Introduction to the Apocynaceae Family

The Apocynaceae family is an important family to learn how to identify. It is a family of often showy, beautiful flowers that are frequently fragrant but also often highly poisonous if ingested. The name “dogbane” comes from this toxic nature that has poisoned livestock and dogs.

The Apocynaceae was recently revised to include the former Asclepiadaceae, or milkweed, family. Molecular phylogenetics provides an excellent reason to do so, and the two families are similar in morphology and other properties. However, there are a few notable differences in the Asclepiadoideae subfamily that I have included in detail in the descriptions below.   

Beginner’s Guide to the Dogbane or Milkweed Family

If you’re new to plant morphology, this section is a perfect beginner’s description to teach you how to identify the Apocynaceae family, with no need to know any scientific jargon. Below is some additional information on the uses of the Apocynaceae family, along with morphology pictures to help you identify family members, and finally, pictures of individual species found in North America.

But for researchers or those wanting to learn a more in-depth version, check out the Scientific Botanical Description below the images in addition to genus-level distribution data.

Leaves and Stems of the Dogbane and Milkweed Family

Perennial or annual herbs, shrubs, woody vines, and trees that all have a characteristic milky white juice (latex) (sometimes clear) that they release when damaged. Leaves are usually simple (not compound) and may be thin to thick and leathery. They are usually arranged in opposite pairs or whorls around the stem. In some species, the leaves are modified into spines, and the stem may appear cactus-like.

Flowers of the Dogbane and Milkweed Family

Flowers are often large, showy, symmetrical, and come in whites, reds, blues, and yellows and may be fragrant, foul-smelling, or odorless. Petals are joined at the base to form a funnel or trumpet shape, often with twisted or contorted lobes in bud, often appearing pinwheel-like. Most flowers have nectaries at their base to attract pollinators.

Reproductive Features of the Dogbane and Milkweed Family

There are 5 male parts (stamens) that are often fused to the female parts (ovary, style, and stigma) to create a unique central structure called a “gynostegium,” but in some lineages they are partially to fully free. There are typically two superior ovaries (which sit above where the petals attach), with a large and conspicuous style head on top that acts as a platform to receive pollen.

Fruits of the Dogbane and Milkweed Family

The fruits are most often large pod-like capsules (follicles) containing numerous seeds accompanied by long silky hairs (comose), which allow them to disperse in the wind. But sometimes the seeds are hairless, and some species produce fleshy berries or drupes (like a cherry with a hard central pit) or dry capsules.

Morphology of Apocynaceae in North America

The first table shows general Apocynaceae family morphology, but then there is a second one below it showing morphology specific to the Asclepiadoideae subfamily of the Apocynaceae.

Some Apocynaceae Species Found in North America

Apocynoideae Subfamily

Adenium obesum – Sabi Star or Desert Rose

This is a drought-deciduous or evergreen shrub that is native to Africa but cultivated elsewhere. It has large, swollen stems with a very enlarged, swollen stem (caudex). Spiral leaves are clustered at branch tips. It has tubular pink flowers 4 – 5 cm wide with 5 petals.

Apocynum androsaemifolium – Spreading Dogbane

This is a branching herbaceous perennial with opposite and more or less egg-shaped to somewhat elliptical leaves. Flowers are small, bell-shaped, whitish-pink, and found mostly in terminal clusters like these. Native throughout North America.

Apocynum cannabinum – Indian Hemp

Erect, herbaceous branching perennial with usually purplish-green stems and with opposite lance-shaped to egg-shaped leaves that usually have white hairs on the lower surface. Flowers are small greenish to cream-colored, usually in terminal inflorescences. Native throughout North America.

Nerium oleander – Oleander or Nerium

This cultivated Apocynaceae species is originally from the Mediterranean. It has thick, leathery, lance-shaped leaves in whorls of 2 – 3. Flowers are deeply 5-lobed with a fringed corolla around the mouth of the floral tube, as seen here in the center of the flower. Flowers are intensely fragrant (perfume).

Pachypodium rutenbergianum—Madagascar Palm

This is a unique-looking tree 3-8 m tall with very thick succulent branches, long spines, and an enlarged stem (caudex). It has long, leathery, oblong to lance-shaped leaves. Flowers are white with a yellow center, petals spreading in a pinwheel shape. Native to Madagascar & cultivated elsewhere.

Trachelospermum jasminoides—Star Jasmine

This is a vigorous, medium-sized evergreen shrub or vine with elliptic to egg-shaped, hairless, glossy, green, leathery leaves. Flowers are in few-flowered clusters on long stalks; they are very fragrant and hairy inside the floral tube. This Apocynaceae member is native to Asia but widely cultivated elsewhere.

Asclepiadoideae Subfamily

Asclepias arenaria – Western Sand Milkweed

Erect herbaceous perennial with densely woolly leaves and stems. Leaves are broadly egg-shaped with wavy (undulate) margins seen in the photo. Flowers are found in the leaf axils and are greenish to cream-colored. This species is endemic to the Great Plains region of the USA and is very drought-tolerant.

Asclepias asperula—Antelope Horns

This is a clump-forming, 1-2 ft tall perennial with long, narrow leaves that are usually folded lengthwise, as shown in the photo. Flowers are usually in roundish terminal inflorescences with greenish flowers with maroon highlights. The fruit are follicles that usually curve like a horn (see photo). It is native to the southwestern USA and northern Mexico.

Asclepias curassavica – Tropical Milkweed

A perennial native of South America but becoming widely introduced elsewhere. Flowers have purple or red corollas and yellow or orange coronas in the center. Leaves are long and narrow with acute tips or tapering to a point. It is not recommended to grow this plant outside of the tropics because it is confusing monarchs into overwintering in temperate climates instead of migrating.

Asclepias engelmanniana – Engelmann’s Milkweed

A tall, slender perennial with 1 – 4 branching stems with long and very narrow linear leaves, usually in groups of 2 – 3. Pale green flowers without horns are crowded in umbels in the upper leaf axils. This species is endemic to the Great Plains of the USA.

Asclepias incarnata—Swamp Milkweed

A herbaceous perennial that is branched on the upper part of the stem and has lance-shaped to linear–oblong leaves. The flower’s corolla is pink to red (rarely white), and the horn curves inward past the hood. This lovely plant is native to swamps and other wet areas of eastern North America.

Asclepias latifolia – Broadleaf Milkweed

This unbranched, 2 – 3 ft tall herbaceous perennial has very large, broad, somewhat egg-shaped or oval leaves with prominent veins. Leaves are densely packed, appearing cabbage-like when young. Flowers are pale greenish to yellow, often hidden in axils by the large leaves. Native to the western USA and northern Mexico, mostly in the Great Plains.

Asclepias pumila – Plains Milkweed

This short herbaceous perennial is usually less than 30 cm tall with narrow leaves that are densely packed, appearing whorled but not upon close inspection. Flowers are light pink or white in terminal inflorescences. This is another endemic of the Great Plains region of the USA.

Asclepias speciosa – Showy Milkweed

Herbaceous perennial up to 1.2 m tall with oppositely arranged, elongated, simple leaves. Large, hairy, pale pink to pinkish-purple flowers appear in dense umbel-like clusters and have very prominent hoods and hooks forming a star shape. Native to western North America.

Asclepias subverticillata – Horsetail Milkweed

This erect, spreading, herbaceous perennial may or may not be branched and grows to 1 m tall with sparse, narrow, linear leaves with margins that roll backward on the edge (revolute) and grow in whorls of 3 – 5 at branch nodes. Star-like whitish or cream flowers grow in the upper leaf axils. It is native to the central and southwestern USA and northern Mexico.

Asclepias syriaca—Common Milkweed

A tall perennial up to 1 m tall with large egg-shaped to somewhat elliptic leaves with pale green on the lower surface. Flowers are in somewhat drooping umbels in leaf axils and are usually pink (rarely white), with horns that bend inwards. The follicles have a very roughly textured surface (shown in the photo). Native to the eastern USA and Canada.

Asclepias tuberosa—Butterfly weed

A bushy herbaceous perennial to 60 cm tall, with a hairy stem that may or may not branch in the top half. Leaves are linear to narrowly egg-shaped and may be arranged opposite or alternate on branches. Flowers are in terminal flat-topped umbels of yellow to red-orange flowers. Native to southeastern Canada and the eastern and southwestern USA.

Asclepias variegata—Red Ring Milkweed

Herbaceous perennial with usually unbranched stems with several pairs of opposite broadly oblong to ovate leaves. Flowers in 1 – 4 rounded, compact umbels with showy white and pinkish-red-tinged flowers with spreading hoods. Native to eastern North America, rare in the north, most common in the southeastern USA.

Asclepias verticillata – Whorled Milkweed

An erect perennial with branching only at the top of the plant (or unbranched) with numerous narrow linear leaves in whorls of 3 – 6. Flowers are in several umbels crowded in the upper axils with white to greenish flowers with somewhat spreading hoods and horns that are larger than the hoods. Native to eastern North America and parts of western North America.

Asclepias viridis – Green Antelope Horns

A herbaceous perennial common on overgrazed pastures and roadsides. Simple leaves, often with wavy (undulate) edges, are arranged alternately on the stems. Flowers are green with purplish hoods, and they lack the horns usually present in the genus. This species is endemic to the south-central and some of the southeastern USA.

Cyanchum laeve – Climbing Milkweed or Sand Vine

This is a climbing vine that is sparsely hairy with opposite heart-shaped leaves with palmate veins. Flowers are in clusters of 5 – 40 flowers in the leaf axils. The fruit is an egg-shaped follicle. Native to central and eastern USA, southeastern Canada

Funastrum clausum—White Twinevine

A tendril-climbing perennial vine with linear to oblong leaves that are hairy and somewhat succulent. Flowers appear in the leaf axils and have soft-hairy white petals. This species is native to the southern USA, Mexico, and the tropical Americas.

Rauvolfioideae Subfamily

Carissa macrocarpa—Natal Plum

Spiny evergreen shrub with leathery, glossy dark green leaves. Flowers are very fragrant and white with long narrow petals. The fruit is a large, reddish, edible drupe (looks like a plum). Native to Africa, cultivated in southern North America and the tropical Americas.

Cascabela ovata—Yellow Oleander

A perennial shrub or tree with spiral, moderately thick, and leathery leaves with prominent veins (pinnate). Flowers are large, showy, tubular, and yellow. The fruit is large, ~rounded, and somewhat plum-like but with multiple large stony seeds, turning purplish when mature. Native and common in Mexico and also Central America.

Catharanthus roseus – Madagascar Periwinkle

An evergreen subshrub with hairless egg-shaped, somewhat glossy leaves arranged in opposite pairs. Flowers are white with yellow or red centers or dark pink with red centers. Native to Madagascar but frequently cultivated in North America.

Plumeria rubra – Red Frangipani

A medium to large shrub or small tree with a succulent trunk and branches. Drought-deciduous or semi-evergreen with large leaves clustered at branch ends. Flowers are white to pink and very fragrant in terminal umbels. Native to Mexico and tropical America, widely cultivated elsewhere.

Rauvolfia tetraphylla – Devil Pepper

A much-branched shrub or small tree with 4 (3 – 5) whorled egg-shaped, elliptic, or ~oblong leaves per node. Flowers are small and white and appear in clusters in the leaf axils. The fruit is a small red 2-seeded drupe (shown in the photo). It is native to Mexico and the tropical Americas.

Vinca major – Greater Periwinkle

A scrambling vine with opposite semi-evergreen leaves with a waxy surface and tiny hairs, sometimes with hairy margins. Flowers are pink to violet, fused at the base, with pinwheel-like lobes. Native to the western Mediterranean, widely cultivated as a groundcover, and highly invasive in some areas.

Vinca minor – Periwinkle

A scrambling vine with opposite hairless evergreen leaves that are smaller and narrower than V. major and never have a hairy margin. Flowers are similar to V. major but a little smaller. This Apocynaceae member is native to Eurasia, widely cultivated and highly invasive in some areas.

Uses of the Apocynaceae Family 

Most parts of many members of the Apocynaceae family are poisonous, hence the common family name of dogbane, since it has been used to poison dogs and other animals. The sap of most is a milky latex, which is often toxic but can sometimes be used for medicine and rubber. In fact, the family is used for cardiac stimulants, chemotherapy, and hypertension in modern pharmacology.

Many ornamental shrubs, trees, herbs, and vines come from this family, including Oleander, Frangipani, Carissa, Plumeria, Vinca, Asclepias, Hoya, Araujia, Ceropegia, Stapelia, Caralluma, Decabelone, etc.

Several species in the basal Ravolfioideae are used as edible fruits, like Carissa macrocarpa, which is the source of the edible natal plum; karanda, which comes from Carissa carandas; and the wild mangaba from Hancornia speciosa. 

Ecosystem and Wildlife Values of the Apocynaceae Family

The famous monarch butterfly requires Asclepias species for reproduction, depositing its eggs on the plants, which hatch into caterpillars that eat the leaves. The monarchs are able to eat the toxic sap without ill effects. Other insects like milkweed beetles, milkweed bugs, and milkweed tussock moths also feed on them, and the Danaine butterflies also depend on the subfamilies Asclepiadoideae, Apocynoideae, and Secamonoideae as larval host plants.

Many Apocynaceae flowers, especially Asclepias, Apocynum, Cynanchum, and Hoya, produce large volumes of sugar-rich nectar for a vast array of generalist native bees, honeybees, wasps, butterflies, and hummingbirds.

The silky coma hairs of Asclepias, Nerium, and Funastrum seeds are extensively used by small songbirds (goldfinches, bushtits, and hummingbirds) to line and insulate nests.

Fleshy-fruited Rauvolfioideae (such as Carissa, Landolphia, Saba, and Willughbeia) serve as critical food sources for frugivorous birds, bats, and primates in tropical ecosystems.

Taxonomy of the Apocynaceae

The Apocynaceae contains 4555 to 5100 species in 400 genera, which belong to five subfamilies. It is part of the Gentianales order of the core eudicots. The recent inclusion of Asclepiadoideae in Apocynaceae greatly increased the number of species and genera. As with most families, thanks to molecular phylogenetics, which is better clarifying our understanding of the plant families, the genera and species have been undergoing revisions. This information is up-to-date as the accepted data currently shows.

Apocynoideae Subfamily

The Apocynoideae is a diverse subfamily of perennial (rarely annual) herbs, shrubs, lianas, and the occasional tree. They exude milky latex, but it is sometimes clear. Leaves are simple and entire and usually exstipulate or have very small stipules and are otherwise quite variable. The stamens converge into a cone and adhere directly to the style head, though they lack pollinaria and do not form a fully fused gynostegium. Fruits are typically paired, dry follicles containing seeds crowned with a conspicuous tuft of silky hairs (coma) for wind dispersal.  

Adenium (6), Aganosma (9), Alafia (25), Allomarkgrafia (10), Allowoodsonia (1), Amalocalyx (1), Amphineurion (1), Anechites (1), Anodendron (17), Apocynum (5), Artia (5), Asketanthera (4), Baharuia (1), Bahiella (2), Baissea (25), Beaumontia (9), Carruthersia (4), Chonemorpha (10), Cleghornia (2), Cycladenia (1), Dewevrella (1), Echites (14), Ecua (1), Elytropus (1), Epigynum (5), Eucorymbia (1), Farquharia (1), Forsteronia (45), Funtumia (2), Galactophora (6), Holarrhena (6), Hylaea (2), Ichnocarpus (3), Isonema (3), Ixodonerium (1), Kibatalia (15), Laubertia (4), Macropharynx (15), Malouetia (32), Mandevilla (183), Mascarenhasia (8), Mesechites (8), Micrechites (15), Motandra (3), Neobracea (8), Nerium (1), Odontadenia (23), Oncinotis (8), Pachypodium (23), Papuechites (1), Parepigynum (1), Parsonsia (85), Pentalinon (2), Pinochia (4), Plectaneia (3), Pleioceras (5), Pottsia (3), Prestonia (63), Rhabdadenia (3), Rhodocalyx (2), Salpinctes (1), Sindechites (1), Spirolobium (1), Stephanostema (1), Stipecoma (1), Streptoechites (1), Strophanthus (39), Temnadenia (2), Thenardia (3), Thoreauea (3), Thyrsanthella (1), Tintinnabularia (3), Trachelospermum (10), Urceola (21), Vallaris (2), Wrightia (34). 

Asclepiadoideae Subfamily

The Asclepiadoideae is a subfamily that can usually be easily recognized by the presence of a gynostegium with its monoadelphous stamens and two styles that are partially joined (free below) to the massive style head. The two carpels are free below, joining at the style head, where lateral receptive stigmatic chambers alternate with the anthers. Pollen is aggregated into waxy pollinia, and the stamens often have complex petaloid outgrowths forming characteristic “hoods” and “horns.” Fruits are always dry, paired (or solitary by abortion) follicles containing comose seeds, and most plants exude milky latex.

Anemotrochus (3), Anisopus (4), Anisotoma (3), Apteranthes (7), Araujia (13), Asclepias (210), Aspidoglossum (37), Aspidonepsis (5), Astephanus (2), Asterostemma (1), Australluma (2), Barjonia (7), Blepharodon (4-6), Calciphila (2), Calotropis (3), Campestigma (1), Caralluma (31), Ceropegia (473), Chlorocyathus (2), Cibirhiza (3), Cionura (1), Conomitra (1), Cordylogyne (2), Cosmostigma (3), Cristobalia (4), Cynanchum (259), Diplolepis (14), Dischidanthus (2), Dischidia (128), Ditassa (114), Dolichopetalum (1), Echidnopsis (36), Emicocarpus (1), Emplectanthus (3), Eustegia (5), Fanninia (1), Fischeria (17), Fockea (6), Funastrum (22), Glossostelma (12), Gomphocarpus (20), Gongronema (7), Gongronemopsis (9), Gonolobus (~140), Gymnema (53), Gymnemopsis (5), Gyrostelma (1), Harmandiella (1), Hemipogon (9), Heterostemma (45), Heynella (1), Hoya (569), Hypolobus (1), Ibatia (36), Jobinia (25), Kanahia (2), Lachnostoma (16), Leptadenia (9), Lygisma (5), Macroscepis (21), Margaretta (1), Marsdenia (69-84), Matelea (181), Metastelma (94), Microloma (11), Minaria (22), Miraglossum (7), Monsanima (2), Nautonia (1), Neoschumannia (3), Nephradenia (5), Oncinema (1), Oreosparte (3), Orthosia (55), Oxypetalum (139), Oxystelma (2), Pachycarpus (39), Papuahoya (3), Parapodium (3), Pentacyphus (3), Pentasacme (6), Pentatropis (4), Peplonia (9), Pergularia (2), Petalostelma (12), Pherotrichis (4), Philibertia (45), Piaranthus (9), Pseudolachnostoma (12), Pycnorhachis (1), Rhyssolobium (1), Rhytidostemma (8), Riocreuxia (10), Rojasia (1), Ruehssia (146), Sarcolobus (22), Schizoglossum (26), Schizostephanus  (2), Schubertia (6), Scyphostelma (39), Sicyocarpus (1), Sisyranthus (15), Solenostemma (1), Stathmostelma (14), Stelmagonum (1), Stenostelma (6), Stephanotis (18), Stigmatorhynchus (2), Suberogerens (1),Talayotea (2), Tassadia (31), Telosma (9), Topea (2), Treutlera (1), Tweedia (6), Tylodontia (4), Vincetoxicum (264), Woodia (3), Xysmalobium (40).

Periplocoideae Subfamily

The Periplocoideae are a subfamily of twining lianas, erect or climbing shrubs, geophytic herbs, or rarely small trees, exuding milky, watery, or clear sap. Colleters are characteristically present at the base/sinuses of the calyx. Filaments are distinct and inserted near the corolla base, with anthers converging over and adhering to the style head. The subfamily is differentiated by pollen shed in tetrads deposited into a spoon-shaped (spatulate) translator bearing an adhesive basal disc (lacking the paired waxy pollinia of Asclepiadoideae). Fruits are paired follicles with comose seeds for wind dispersal.  

Atherandra (1), Baroniella (10), Baseonema (1), Batesanthus (3), Buckollia (2), Camptocarpus (9), Cryptolepis (34), Cryptostegia (2), Decalepis (5), Ectadium (2), Epistemma (4), Finlaysonia (6), Gymnanthera (2), Hemidesmus (1), Ischnolepis (1), Maclaudia (1), Mondia (2), Myriopteron (1), Pentopetia (23), Periploca (17), Petopentia (2), Phyllanthera (10), Raphionacme (36), Sacleuxia (2), Sarcorrhiza (1), Schlechterella (2), Stomatostemma (1), Streptocaulon (5), Tacazzea (5), Telectadium (3), Zygostelma (1). 

Rauvolfioideae Subfamily

The Rauvolfioideae forms the basal grade of the Apocynaceae. They are a diverse subfamily divided into eleven tribes. In general, they are mostly pantropical trees, shrubs, and some lianas, with just a few temperate herbaceous lineages. They also have variable fruit and floral morphology but generally have stamens that are free from the style head, which separates them from the Apocynoideae and Asclepiadoideae. They also have actinomorphic flowers, usually salverform or rotate with petals often overlapping with left-contorted aestivation, giving them a “pinwheel” look. They have highly variable fruits but often produce fleshy drupes or berries, or paired dry follicles with unwinged or hairless seeds (no silky comas).  

Acokanthera (5), Allamanda (16), Alstonia (44), Alyxia (117), Ambelania (3), Amsonia (17), Ancylobothrys (8), Aspidosperma (80), Bousigonia (3), Callichilia (6), Calocrater (1), Cameraria (7), Carissa (9-15), Carvalhoa (2), Cascabela (6), Catharanthus (9), Cerbera (6), Cerberiopsis (3), Chamaeclitandra (1), Chilocarpus (14), Clitandra (1), Condylocarpon (7), Couma (5), Craspidospermum (1), Crioceras (1), Cyclocotyla (1), Cylindropsis (1), Dictyophleba (6), Diplorhynchus (1), Dyera (2), Geissospermum (5), Gonioma (2), Hancornia (1), Haplophyton (2), Himatanthus (9), Hunteria (9), Kamettia (2), Kopsia (25), Lacmellea (24), Landolphia (63), Laxoplumeria (5), Lepinia (4), Lepiniopsis (2), Leuconotis (4), Macoubea (3), Melodinus (25), Microplumeria (1), Molongum (3), Mortoniella (1), Mucoa (2), Neocouma (2), Ochrosia (44), Orthopichonia (6), Pacouria (3), Parahancornia (7), Petchia (8), Picralima (1), Pleiocarpa (7), Plumeria (10-18), Pteralyxia (2), Pycnobotrya (1), Rauvolfia (78), Rhigospira (1), Saba (3), Schizozygia (1), Skytanthus (3), Spongiosperma (6), Stephanostegia (2), Strempeliopsis (2), Tabernaemontana (126), Tabernanthe (2), Thevetia (3), Vahadenia (2), Vallesia (10), Vinca (7), Voacanga (22), Willughbeia (16),

Secamonoideae Subfamily

The Secamonoideae are a small subfamily of twining lianas or climbing vines; rarely, they may be shrubs (Madagascar). Leaves are simple, opposite, and entire, sometimes bearing adaxial colleters. Flowers are characteristically small to minute, with a fully developed gynostegium. The subfamily is best differentiated by its pollinia arrangement, producing 4 pollinia per pollinarium (2 per anther theca) attached to a central corpuscular translator. Fruits are paired, slender to fusiform follicles that contain comose seeds.

Calyptranthera (13), Genianthus (17), Goniostemma (2), Pervillaea (5), Secamone (150), Secamonopsis (2), Toxocarpus (29), Trichosandra (1).

Key Differences From Other Families

The Apocynaceae can be confused with the Rubiaceae (Coffee/Madder), who share opposite, entire leaves, sympetalous 4-5-merous flowers, and woody or herbaceous habit. The Rubiaceae, however, almost never have a milky latex and have prominent interpetiolar stipules and strictly inferior ovaries.

They are also confused with the Gentianaceae, which also share similar leaves without stipules and sympetalous flowers with contorted corollas, but the sap of the Gentianaceae is always clear, never milky, and they have a single syncarpous ovary. They also lack the specialized pollinia and other features of the Apocynaceae.

The Euphorbiaceae are another family occasionally confused with the Apocynaceae, mostly because of their abundant milky latex, and some succulent forms resemble succulent Apocynaceae. However, Euphorbiaceae flowers are highly reduced unisexual pseudanthaia (cyathia) subtended by petal-like glands.

Scientific Botanical Description of the Apocynaceae

This section is for researchers and others who want a more thorough, scientific botanical description of the Apocynaceae family.

Habit & Leaf Form of the Apocynaceae Family

The Apocynaceae are mostly perennial or annual herbs, shrubs, and lianas, which may be root climbers, scramblers, and stem twiners. However, some trees are also seen, which may develop buttress roots (a few in Tabernaemontana and Dyera). Some plants may be switch plants with succulent, photosynthetic stems. Others have peculiar vegetative forms, such as leaves modified into passive pitcher traps in Dischidia rafflesiana. All forms are laticiferous, containing a milky or sometimes watery or clear latex characteristic of the family.

Leaves are simple and usually well-developed but may be very reduced. They may be herbaceous, leathery, membranous, succulent, or rarely modified into spines. They are mostly attached opposite or whorled (3-8 per whorl) or rarely alternate. Stipules are usually absent or highly reduced; when present, they are often modified into colleters or pairs of sharp spines. Domatia are sometimes seen as pits, pockets, or hair tufts.

The leaf lamina is entire and is frequently pinnately veined but is sometimes one-veined or palmately veined. It is usually dorsiventral, sometimes bifacial, or isobilateral in Nerium oleander. The epidermis frequently contains crystal idioblasts, and diverse hairs are often found, which may be simple eglandular to multicellular glandular shaggy hairs at the lamina bases and on the petiole.

Flowers of the Apocynaceae Family

Apocynaceae plants are predominantly hermaphroditic, tetracyclic, actinomorphic, and 5-merous (rarely 4-merous) and adapted for specialized entomophilous pollination (often utilizing clip mechanisms, guide rails, or temporary pitfall traps). Inflorescences are terminal or axillary, solitary or arranged in cymes, panicles, thyrses, or umbelliform cymes, typically subtended by bracts and bracteoles.

The flowers are often large and showy and may be malodorous, fragrant, or odorless. A basal annular or lobed hypogynous nectariferous disk is usually present in Rauvolfioideae and Apocynoideae but is replaced by internal stigmatic chamber nectaries in Asclepiadoideae.

The perianth is biseriate with a distinct calyx and corolla. The calyx has five parts in one whorl, is usually connate (at least basally), is regular, and is quincuncial, imbricate, or valvular; the adaxial base often bears secretory colleters.

The corolla also has five parts in one whorl and may or may not be appendaged. The corolla is connate (ranging from rotate, campanulate, and salverform to tubular, funnelform, or urceolate), with lobes shorter or longer than the tube.

Aestivation is predominantly contorted, typically sinistrorse (overlapping to the left) in Rauvolfioideae and dextrorse (overlapping to the right) in Apocynoideae/Periplocoideae, or valvate in derived Asclepiadoideae. The throat or tube often bears internal appendages forming a corolline corona (Nerium, Strophanthus). Corolla colors span white, cream, yellow, green, orange, red, pink, purple, violet, and mottled brown/black.

Androecium of the Apocynaceae Family 

The androecium varies heavily, depending on the subfamily. In general, it consists of a single whorl of 5 distinct, fertile stamens alternating with the corolla lobes (haplostemonous, isomerous). Filaments are epipetalous, inserted near the corolla tube base (in Asclepiadoideae and Periplocoideae), midway down the tube, or within the throat.

In Rauvolfioideae, the filaments and anthers are completely free from one another and free from the style head.

In Apocynoideae, the filaments are distinct, but the anthers are connivent (often sagittate with sterile, tailed bases) and postgenitally adhere to the style head via sticky secretions, forming an anther cone.

The Periplocoideae have distinct filaments inserting near the tube’s base. The anthers converge and adhere to the style head, shedding pollen tetrads into spoon-like translators.

In the Secamonoideae and Asclepiadoideae, the filaments are connate into a monadelphous tube that is congenitally fused to the massive style head, forming a true gynostegium. In Asclepiadoideae, anthers bear sclerified lateral guide rails (horny wings) and terminal membranous connective appendages, while the filament tube bears complex dorsal outgrowths forming a nectariferous staminal corona (hoods and horns).

Anthers are basifixed, introrse, non-versatile, and dehisce longitudinally. They are dithecal and tetrasporangiate in the basal subfamilies, reducing to bisporangiate in Asclepiadoideae (where each theca holds a single pollinium).

Gynoecium of the Apocynaceae Family

The gynoecium is typically bicarpellate (rarely 3–5 or up to 8 carpels in Pleiocarpa). Across most of the family, the carpels and their lower styles are free (apocarpous), uniting postgenitally only at the apex into a single, massively enlarged style head (synstylous). Truly syncarpous ovaries occur in select basal clades (e.g., Allamanda, Carissa).

The ovary is superior to semi-inferior (rarely inferior). The carpels are oriented transversely across most basal lineages but are oriented medially (anteroposterior) in Asclepiadoideae.

Placentation is marginal in the typical apocarpous/synstylous condition, with each free carpel bearing 2 to >100 ovules along the ventral suture, or parietal when syncarpous and unilocular (Allamanda) or axile when syncarpous and bilocular (Carissa).

Ovules are pendulous, anatropous to hemianatropous, unitegmic, and tenuinucellate (Apocynoideae/Rauvolfioideae) or pseudocrassinucellate (Asclepiadoideae).

Rather than a conventional apical receptive surface, the style head is expanded into a pentagonal, capitate, or spool-shaped structure. It is often equipped with a basal collar, a ring of hairs, or secretory translator-producing zones. The true receptive stigmatic surfaces are localized laterally or on the underside in specialized chambers alternating with the stamen attachments.

Fruit of the Apocynaceae Family

The fruits of Apocynaceae are typically a pair of dry, dehiscent follicles (follicetum) opening along the ventral suture, but it’s often solitary via abortion of one carpel.

However, in Rauvolfioideae they are more variable, often paired or solitary fibrous drupes, or berries, but may also be a spiny bivalved dehiscent capsule or large woody follicles.

Seeds are usually flat and are conspicuously comose in the Apocynoideae, Periplocoideae, Secamonoideae, and Asclepiadoideae. But they may be hairless, winged, or unadorned. Seeds are oily, and an endosperm is usually present.

Global Distribution of the Apocynaceae

The Apocynaceae are mostly subtropical to tropical shrubs, trees, and herbs, with a few temperate representatives. They are cosmopolitan in distribution, found everywhere except Antarctica. In the American continents, they are widespread throughout, including some herbaceous Apocynaceae species that reach as far north as Arctic Canada. 

Distribution of Apocynaceae in the Americas

Canadian Apocynaceae Genera

Apocynoideae in Canada

Apocynum 2 spp. native in almost all of Canada, including the Arctic but excluding NU and Labrador, with 1 NAM hybrid sp. also native in this range.

Asclepiadoideae in Canada

Asclepias 15 spp. native in all S provinces but intro in NL (absent in Labrador); Cynanchum 1 sp. intro in ON; Vincetoxicum 3 spp. intro to BC, ON, QC, and NB.

Rauvolfioideae in Canada

Vinca 2 spp. intro to BC, ON, QC, NS, and NB.

USA Apocynaceae Genera

Apocynoideae in the USA

Apocynum 2 spp. native to all of the USA, including AK, plus 1 NAM hybrid sp. native in this range; Beaumontia 1 sp. intro HI; Cycladenia monospecific SW USA endemic to CA, OR, AZ, and UT; Echites 1 sp. native to FL; Mandevilla 4 spp. native to AZ, NM, and TX; Nerium monospecific sp. intro to most of S border states exc. NM, also in UT and CA; Pentalinon 1 Mexico, CAM & Caribbean endemic sp. native to S FL; Rhabdadenia 1 S NAM & neoendemic sp. native to FL; Thyrsanthella monospecific SE USA endemic to OK, TX, MO, AR, LA, IL, IN, KY, TN, MS, AL, GA, FL, SC, NC, VA, and DE; Trachelospermum 2 spp. intro to TX, OK, MO, AR, LA, MS, AL, GA, FL, SC, NC, VA, MD, DE, TN, KY, IL, and IN. 

Asclepiadoideae in the USA

Araujia 2 former neoendemic spp. intro to CA, GA, and FL; Asclepias 75 spp. native to all the continental states and HI, with some intro in some states; Calotropis 2 spp. intro to CA, FL, and HI; Cynanchum 17 spp. native and intro to most of the USA exc WA, OR, WY, MT, CO, ND, and SD; Funastrum 5-7 spp. native to CA, NV, UT, CO, AZ, NM, TX, OK, AR, and FL; Gomphocarpus 1 sp. intro to CA?; Gonolobus 3 spp. native to AZ, KS, OK, TX, MO, AR, LA, IL, IN, KY, TN, MS, AL, GA, FL, NC, SC, VA, and MD; Hoya 1 sp. intro to HI; Matelea 24 spp. (may be less now that genus has been reduced) sp. native to the most southern states; Metastelma 7 spp. native to AZ, NM, TX, and FL; Orthosia 2 spp. native to MS, FL, GA, and SC; Pherotrichis 1 sp. native to AZ; Suberogerens monospecific endemic of W+SE Mexico, and Ver; Vincetoxicum 3 spp. intro to CA, NE, KS, MN, MO, MI, WI, IL, IN, KY, OH, PA, NJ, MD, NY, CT, RI, MA, VT, NH, and ME.

Periplocoideae in the USA

Cryptostegia 2 spp. intro to TX and FL; Periploca 1 sp. intro to KS, OK, TX, TN, VA, PA, NJ, NY, CT, and RI.

Rauvolfioideae in the USA

Allamanda 1 former neoendemic sp. intro to FL; Alstonia 1 sp. intro to FL and HI; Alyxia 1 Pacific sp. native to HI; Amsonia 16 spp., including 14 native to all of S USA from CA E to NJ but excluding WV, which includes 7 endemic to the USA and 3 narrow endemics of AZ (2) and NM (1), and includes 2 spp. intro to NY, CT, and MA; Carissa 1 sp. intro to AZ, TX, and FL; Catharanthus 1 sp. intro to CA, TX, LA, MS, FL, GA, SC, NC, OH, and HI; Haplophyton 1 S NAM & N CAM endemic spp. native to AZ, NM, and TX; Ochrosia 4 spp. native to HI and intro to FL; Plumeria 1 sp. native FL; Pteralyxia 2 spp. endemic genera of HI; Rauvolfia 3 spp. inc. native in FL, and intro and native in HI; Tabernaemontana 2 spp. native to FL and intro HI; Thevetia 1 Neo sp. intro to TX, FL, and HI; Vallesia 2 spp., including 1 native and 1 intro to CA and FL; Vinca 3 spp. intro to most of the USA, except NV, OK, CO, WY, ND, and SD.

Mexico Apocynaceae Genera

Apocynoideae in Mexico

Apocynum 1 sp. native to N Mexico, plus 1 NAM hybrid sp. native in this range; Echites 7 NAM, CAM & Caribbean spp. native to most of Mexico, exc. BC, BCS, Son, and Sin, and inc. 1 endemic to SW+C Mexico; Forsteronia 1-3 spp. neoendemic genus native to SW+SE Mexico, Ver, Chp; Laubertia 1 Mexico endemic sp. in most of Mexico exc. Ver; Mandevilla ~22 spp. native (~1/2 endemic) to all of Mexico; Mesechites 1 Mexico & Neoendemic sp. native to Mexico except for BC, BCS, Son, Sin, Mex, Cd Mex, Pue, Tlx, and Mor; Nerium monospecific sp. intro to most of Mexico exc. BC, BCS, Son, Sin, and Ver; Odontadenia 1 neoendemic sp. native SW+SE Mexico, Chp; Pentalinon 1 sp. native SW+C+SE Mexico; Pinochia 2 spp. Mexico & N neoendemic genus native to SW+SE Mexico, Chp, and Ver; Prestonia ~5 spp. native to most of Mexico exc. BC, BCS, Son, and Sin; Rhabdadenia 1 S NAM & neoendemic sp. native to Ver, Cam, Tab, Yuc, QR, and Chp; Thenardia 3 spp. Mexico & Honduras endemic genus native to SW+C+SE Mexico, inc. 2 endemics; Thoreauea 3 spp. endemic genus of SW Mexico + Ver; Tintinnabularia 2 spp. Mesoamerica endemic genus native to Oax, Chp, and Ver, inc. 1 narrow endemic of Ver.  

Asclepiadoideae in Mexico

Asclepias 70+ spp. native to all of Mexico; Calotropis 1 sp. intro to SW+C+SE Mexico; Cynanchum several spp. native to all of Mexico; Fischeria 1 Neoendemic sp. native to SW+C+SE Mexico; Funastrum 13 spp. native throughout all of Mexico, including 3 endemics; Gomphocarpus 1 sp. intro to SW Mexico; Gonolobus ~50 spp., about half of which are endemic and native to all of Mexico; Jobinia 1 sp. native Ver; Macroscepis 5 Mexico & neoendemic spp. native to all of Mexico, including 2 narrow endemics; Matelea ~70 spp., ~60% endemic to all of Mexico; Metastelma ~30 spp. native to all of Mexico, including Mexican Pacific Is., including many endemics; Orthosia 9 spp. inc. 6 endemics native to all of Mexico; Oxypetalum 1-2 spp. native to NE+SW+SE Mexico and Ver; Pherotrichis 4 spp. Mexico & N CAM endemic genus native to most of Mexico except Ver, including 2 Mexican endemics of SW Mexico; Ruehssia ~40 Mexico & neoendemic spp. native to all of Mexico, with ~68% endemism; Stelmagonum is monospecific and endemic to SW Mexico; Talayotea 2 spp. endemic genera of most of Mexico except Ver; Tassadia 1 neoendemic sp. native to SW+SE Mexico and Ver. 

Periplocoideae in Mexico

Cryptostegia 2 spp. intro to W+SE Mexico.

Rauvolfioideae in Mexico

Allamanda 1 former neoendemic sp. intro to SW+C Mexico; Alstonia 1 sp. native to SW+C+SE Mexico; Amsonia 4 spp. native to N Mexico; Aspidosperma 5-7+ neoendemic spp. native to SW+SE Mexico, Ver., including 2 endemics; Cameraria 1 former Mexico + N neoendemic sp. native to SE Mexico; Carissa 1 sp. intro to SW+C Mexico; Cascabela 5 spp. native to all of Mexico, including 3 endemics; Catharanthus 1 sp. intro to SW+SE Mexico; Haplophyton 2 S NAM & N CAM endemic spp. native to most of Mexico except Ver; Plumeria 2 spp. native to all of Mexico; Rauvolfia 3-4 spp. native to all of Mexico; Tabernaemontana ~16 spp. native to all of Mexico, including 6 endemics; Thevetia 1 sp. native to most of Mexico except BC, BCS, Son, and Sin; Vallesia 8 spp. native to all of Mexico, inc. 5 narrow endemics; Vinca 1 sp. intro to SW+C+SE Mexico.

Neotropical Apocynaceae Genera

Apocynoideae in the Neotropics

Allomarkgrafia 10 spp. neoendemic genus of Honduras S to Colombia, Ecuador, and Peru; Anodendron 1 sp. intro to Trinidad-Tobago; Asketanthera 4 spp. Greater Antilles endemic genus of Cuba, the Dominican Republic, and Haiti; Bahiella 2 spp. narrow endemic genus of NE Brazil; Beaumontia 1 sp. intro to Costa Rica, Guatemala, El Salvador, and Honduras; Echites 13 spp. native to CAM, the Bahamas, Turks-Caicos, the Greater Antilles, and the Leeward Islands, including 4 narrow endemics of Cuba (2), Costa Rica (1), and Panama (1); Forsteronia 45 spp. neoendemic genus of Cuba, Jamaica, Trinidad-Tobago, CAM, and tropical SAM S to N Argentina (exc. N Chile); Funtumia 1 sp. intro to Cuba, Puerto Rico, Trinidad-Tobago, and El Salvador; Galactophora 6 SAM endemic spp. of Colombia, N+C Brazil, Venezuela, Guyana, Peru, and Bolivia; Hylaea 2 spp. N SAM endemic genus of S Venezuela and N Brazil; Laubertia 3 spp. neoendemic genus of Belize (1 endemic), Colombia, Venezuela, N Brazil (1 endemic), Ecuador, Peru, and Bolivia; Macropharynx 15 neoendemic spp. of Honduras, Costa Rica, Panama, Colombia, Venezuela, Guyana, Suriname, Ecuador, Peru, Bolivia, Paraguay, Brazil, and N Argentina; Malouetia ~20 spp. native to CAM (exc. El Salvador), Windward Is, Colombia, Venezuela, French Guiana, Suriname, Guyana, Brazil (exc. C Brazil), Peru, and Bolivia, and intro to Cuba; Mandevilla ~165 spp. mostly neoendemic genus native to CAM, Cuba, Jamaica, Trinidad-Tobago, and tropical SAM S to N Argentina (exc. N Chile); Mesechites 8 spp. mostly neoendemic genus native to CAM, Cuba (2 endemics), Hispaniola (1 endemic), Jamaica, Trinidad-Tobago, and tropical SAM S to N Argentina (excluding Uruguay and N Chile); Neobracea 8 spp. narrow single-island endemics of Cuba (7) and Cuba + the Bahamas (1); Nerium monospecific sp. intro to CAM and S Brazil; Odontadenia 23 spp. neoendemic genus native to CAM (exc. El Salvador), Hispaniola, Colombia, N+E+C Brazil, Venezuela, Guyana, Suriname, French Guiana, Ecuador, Peru, Bolivia, and Trinidad-Tobago and intro to the Windward Is.; Pentalinon 2 spp. native to the Bahamas, Turks & Caicos, Greater Antilles, SW Caribbean, Leeward & Windward Is., Guatemala, Belize, El Salvador, Honduras, and Nicaragua; Pinochia 4 spp. mostly N neoendemic genus native to Guatemala, Belize, Nicaragua, Costa Rica, Panama, and the Greater Antilles (exc. Cayman Is. & inc. 2 endemics); Prestonia 63 spp. Mexico & neoendemic genus native to CAM, tropical SAM S to N Argentina (exc. N Chile), Leeward & Windward Is., and Trinidad-Tobago; Rhabdadenia 3 spp. native to CAM, Bahamas, Greater Antilles, Leeward & Windward Is., Trinidad-Tobago, and tropical SAM S to N Argentina (exc. N Chile); Rhodocalyx 2 spp. SAM endemic genus of Peru, Bolivia, C+E+S Brazil, Paraguay, and N Argentina; Salpinctes monospecific endemic of S Colombia; Stipecoma monospecific SAM endemic of Bolivia and C+E Brazil; Strophanthus 1 sp. intro to Trinidad-Tobago; Temnadenia 2 spp. endemic genera of Brazil (exc. N); Thenardia 1 S Mexico + Honduras endemic sp. native to Honduras; Tintinnabularia 2 spp. Mesoamerica endemic genus native to Guatemala and Honduras (1 endemic).

Asclepiadoideae in the Neotropics

Anechites monospecific N neoendemic genus of Honduras S to Colombia, Venezuela, Ecuador, and Peru, plus the Greater Antilles; Anemotrochus 3 spp. Caribbean endemic genus of the Bahamas, Turks-Caicos, Cuba, Hispaniola, and Jamaica; Araujia 13 spp. former S SAM endemic genus native Bolivia, C+SE+S Brazil, Paraguay, Uruguay, and Argentina, and intro in C Chile; Asclepias 12 spp. native to CAM, Bahamas, Turks-Caicos, Antilles (exc. Aruba), Trinidad-Tobago, Galapagos, and most of SAM, exc. Chile and intro in N Chile; Barjonia 7 spp. SAM endemic genus of Brazil, Suriname, and Bolivia; Blepharodon 4 spp. SAM endemic genus native to Bolivia, C+S+SE Brazil, NE Argentina, and Paraguay; Calotropis 2 spp. intro to Bahamas, Turks and Caicos, Antilles, Trinidad-Tobago, Colombia, Venezuela, N+C+E Brazil, Paraguay, and Bolivia; Cristobalia 2 spp. native to Bolivia, Uruguay, N Argentina, and S Brazil; Cynanchum ~15 spp. native in CAM, Cuba, Jamaica, tropical SAM S to N Argentina (exc. N Chile); Diplolepis 9 spp. S SAM endemic genus native to N+C Chile, NW Argentina, including 4 narrow endemics of Chile, the rest in Patagonia; Ditassa 114 SAM endemic spp. of Colombia S to N Argentina, except N Chile and Paraguay; Fischeria 17 spp. neoendemic genus native from S Mexico S through CAM (exc. El Salvador), Cuba, Jamaica, Trinidad-Tobago, Colombia, Venezuela, Ecuador, Peru, Bolivia, Brazil, Paraguay, and NE Argentina; Funastrum 12+ spp. native to the Antilles (exc. Aruba, Leeward, Netherlands Antilles), Trinidad-Tobago, CAM, and tropical SAM S to N Argentina (exc. N Chile), including 5 narrow endemics of Guatemala, Bolivia, Colombia, SE Brazil, and Galapagos; Gomphocarpus 1 sp. intro to CAM (exc. Belize), Cuba, Jamaica, Puerto Rico, Leeward Is, Colombia, Venezuela, Suriname, Brazil, Uruguay, NE Argentina, Ecuador, Peru, and Bolivia; Gonolobus ~100 spp. native to Greater Antilles (exc. Cayman Is.), Leeward & Windward Is., CAM, and tropical SAM S to N Argentina (exc. N Chile, Suriname, French Guiana); Gyrostelma monospecific endemic of C+SE Brazil; Hemipogon 8 spp. SAM endemic genus of Peru, Brazil, Bolivia, and Paraguay; Hoya 1 sp. intro to Cuba, Trinidad-Tobago, Puerto Rico, and Leeward Is.; Hypolobus monospecific endemic of NE Brazil; Ibatia 36 spp. neoendemic genus of Honduras, Nicaragua, Panama, Cuba, Hispaniola, Puerto Rico, Lesser Antilles, Colombia, Venezuela, Guyana, Brazil, Paraguay, Ecuador, Bolivia, and N Argentina; Jobinia 25 spp. neoendemic genus native to Guatemala, Honduras, Venezuela, Ecuador, Peru, Bolivia, C+S+E Brazil, N Argentina, and Uruguay; Lachnostoma 16 spp. N SAM endemic genus of Colombia, Ecuador, Peru, and Venezuela; Macroscepis 19 spp. Mexico & neoendemic genus native to CAM (exc. Belize), Colombia, Venezuela, Guyana, Ecuador, Peru, Bolivia, Paraguay, N Argentina, and Brazil; Matelea ~140 spp. native to CAM, Bahamas, Greater Antilles (exc. Cayman Is.), Leeward & Windward Is., Trinidad-Tobago, and tropical SAM S to N Argentina (exc. N Chile); Metastelma ~85-90 spp. native to the Bahamas, Turks and Caicos, Antilles, CAM, Colombia, Venezuela, Guyana, N+E+S Brazil, Ecuador, Peru, Bolivia, Paraguay, and N Argentina; Minaria 22 spp. SAM endemic genus of Brazil, Bolivia, and NE Argentina; Monsanima 2 spp. narrow endemic genus of E Brazil; Nautonia monospecific E SAM endemic genus of C+SE+S Brazil, Paraguay, and NE Argentina; Nephradenia 5 spp. N SAM endemic genus of Colombia, Venezuela, Guyana, N+E+C Brazil, and Bolivia; Orthosia ~48 spp. neoendemic genus native to CAM (exc. Belize), Colombia, Venezuela, E+S Brazil, Uruguay, N Argentina, Ecuador, Peru, Bolivia, Paraguay, Bahamas, and the Greater Antilles (exc. Cayman Is); Oxypetalum 139 spp. mostly neoendemic genus of Guatemala, Honduras, Costa Rica, Panama, Greater Antilles (exc. Cayman Is), Leeward Is, Colombia, Venezuela, Guyana, Brazil, Ecuador, Peru, Bolivia, Paraguay, Uruguay, and N Argentina; Pentacyphus 3 spp. N SAM endemic genus of high Andean Venezuela, Colombia, Ecuador, and Peru, including 1 narrow endemic of Caldas, Colombia; Peplonia 9 spp. SAM endemic genus of Peru, Bolivia, E+C+S Brazil, and Paraguay; Petalostelma 7 spp. SAM endemic genus of Brazil, Bolivia, Paraguay, and N Argentina; Pherotrichis 1 sp. native to Guatemala; Philibertia 41 spp. SAM endemic genus of Ecuador, Peru, Bolivia, N+C Chile, and Argentina; Pseudolachnostoma 12 spp. neoendemic genus of Nicaragua, Costa Rica, Panama, Colombia, Ecuador, Peru, Venezuela, N Brazil, and Trinidad-Tobago; Rhytidostemma 8 spp. neoendemic genus of Panama, Colombia, Venezuela, Guyana, Suriname, French Guiana, C+N Brazil, Ecuador, and Peru; Rojasia monospecific SAM endemic genus of Bolivia, Paraguay, S Brazil, and NE Argentina; Ruehssia ~120+ spp. Mexico & neoendemic genus native to CAM, much of the Antilles, and tropical SAM S to N Argentina (exc. N Chile); Schubertia 6 spp. SAM endemic genus of Colombia, Peru, Bolivia, Paraguay, Brazil, and N Argentina; Scyphostelma 39 spp. neoendemic genus of Costa Rica, Panama, Colombia, Venezuela, Ecuador, Peru, and Bolivia; Stephanotis 1 sp. intro to Cuba, Hispaniola, Puerto Rico, Leeward Is., and Trinidad-Tobago; Tassadia 31 spp. neoendemic genus native to S Mexico, Cuba, Trinidad-Tobago, Belize, Nicaragua, Costa Rica, Panama, and tropical SAM S to Peru, Bolivia, Paraguay, and S Brazil; Topea 2 spp. narrow endemic genus of WC Brazil, Paraguay, and NE Argentina; Tweedia 6 spp. S SAM endemic genus of Bolivia, N+C Chile, Argentina, and Paraguay, with most being narrow endemics; Tylodontia 4 spp. narrow endemic genus of Cuba.  

Periplocoideae in the Neotropics

Cryptostegia 2 spp. intro to CAM (exc. Guatemala, Belize), the Bahamas, the Antilles, Trinidad-Tobago, Colombia, Venezuela, and N+NE+C Brazil.

Rauvolfioideae in the Neotropics

Allamanda 15 spp. of former neoendemic genera native to tropical SAM S to Bolivia, NE Argentina, and S Brazil, excluding Ecuador and Paraguay and intro to Honduras, Nicaragua, Costa Rica, Panama, Guatemala, Belize, El Salvador, Trinidad-Tobago, and Galapagos; Alstonia 1 sp. native to CAM (exc. Belize) and intro in Trinidad-Tobago; Ambelania 3 spp. SAM endemic genus of Colombia, Venezuela, Peru, N+NE Brazil, French Guiana, Guyana, and Suriname; Anechites monospecific N neoendemic of Honduras S to Colombia, Venezuela, Ecuador, and Peru, and the Greater Antilles (exc. Cayman Is.); Aspidosperma ~78 spp. neoendemic genus native from S Mexico S through CAM and tropical SAM S to N Argentina (except N Chile), Hispaniola, Trinidad-Tobago, and the Venezuelan Antilles; Cameraria 7 spp. native to Belize, Guatemala, Cuba (4 endemics), Hispaniola (2 endemics), Jamaica, and the Greater Antilles; Carissa 1 sp. intro to Honduras, Nicaragua, Bahamas, Jamaica, Puerto Rico, Leeward & Windward Is, and Trinidad-Tobago; Cascabela 3 spp. native CAM S through tropical SAM to Peru, Bolivia, NE Argentina, SE Brazil (exc. NE Brazil), and intro to Bermuda, Bahamas, Antilles (exc. Cayman Is., Netherlands Antilles); Catharanthus 1 sp. intro to CAM, Bahamas, Turks-Caicos, Antilles (exc. Cayman Is., Venezuelan Antilles), SW Caribbean, the Galapagos, and French Guiana; Cerbera 1 sp. intro to Trinidad-Tobago; Chamaeclitandra monospecific intro to Trinidad-Tobago; Condylocarpon 7 spp. neoendemic genus of Nicaragua, Costa Rica, Colombia, Venezuela, Brazil, French Guiana, Guyana, Suriname, Paraguay, Peru, Uruguay, NE Argentina, and Trinidad-Tobago; Couma 5 spp. neoendemic genus of Guatemala, Belize, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, Suriname, Guyana, French Guiana, N+NE Brazil, Ecuador, Peru, and Bolivia; Geissospermum 5 spp. SAM endemic genus of Venezuela, Guyana, Suriname, French Guiana, N+E Brazil, Peru, and Bolivia; Hancornia monospecific SAM endemic genus of Bolivia, Brazil, Paraguay, and Peru; Haplophyton 2 spp. native to Guatemala and introduced in Cuba; Himatanthus 9 spp. neoendemic genus of Panama and tropical SAM S to Peru, Bolivia, and C+SE Brazil; Kopsia 1 sp. intro to Trinidad-Tobago; Lacmellea 24 spp. neoendemic genus native to CAM (exc. El Salvador), and tropical SAM S. to Peru, Bolivia, and C+E Brazil; Landolphia 1 sp. intro to Trinidad-Tobago; Laxoplumeria 5 spp. neoendemic genus of Panama, Colombia, Ecuador, Peru, Bolivia, Brazil, and French Guiana; Macoubea 3 spp. neoendemic genus of Costa Rica, Panama, Colombia, Peru, Bolivia, Venezuela, Guyana, Suriname, French Guiana, and N+NE Brazil; Microplumeria monospecific N SAM endemic genus of Colombia, Venezuela, and N Brazil; Molongum 3 spp. N SAM endemic genus of Colombia, Venezuela, and N Brazil; Mortoniella monospecific CAM endemic to Belize, Nicaragua, and Costa Rica; Mucoa 2 spp. N SAM endemic genus of Colombia, Venezuela, N Brazil, and Peru; Neocouma 2 spp. N SAM endemic genus of Colombia, Venezuela, Peru, and N Brazil; Pacouria 3 spp. N SAM endemic genus of Colombia, Venezuela, Guyana, Suriname, French Guiana, N+SE Brazil, Bolivia, and Peru; Parahancornia 7 spp. NW SAM endemic genus of Colombia, Venezuela, Guyana, Suriname, French Guiana, N Brazil, Peru, and Bolivia; Plumeria 18 spp. native to CAM, Colombia, Venezuela, Guyana, Bahamas, Turks-Caicos, Antilles (exc. Aruba, Netherlands Antilles), and SW Caribbean and now intro to Ecuador, Peru, Bolivia, Paraguay, Netherlands Antilles, and Trinidad-Tobago; Rauvolfia ~25 spp. native to CAM, Antilles (exc. Netherlands Antilles), tropical SAM S to N Argentina (exc. Uruguay, N Chile); Rhigospira monospecific N SAM endemic genus of Colombia, Venezuela, N Brazil, and Peru; Skytanthus 3 spp. narrow SAM endemic genus of E Brazil (2), N+C Chile (1); Spongiosperma 6 spp. N SAM endemic genus of Colombia, Venezuela, and N+NE Brazil; Strempeliopsis 2 spp. single island endemic genus of Cuba (1) and W Jamaica (1); Tabernaemontana ~45 spp. native to the Antilles (exc. Aruba, Netherlands Antilles), SW Caribbean, tropical SAM S to Peru, Bolivia, and NE Argentina; Thevetia 3 spp. Mexico & neoendemic genus native to CAM, Cuba, Colombia, Venezuela, N & C Brazil, Bolivia, Paraguay, and NE Argentina; Vallesia 6 spp. native to Cuba, Hispaniola, Jamaica, Belize, Guatemala, El Salvador, Honduras, Costa Rica, Colombia, Venezuela (1 endemic), N Brazil, Peru, Bolivia, Paraguay, N Argentina, and Galapagos (1 endemic); Vinca 2 spp. intro to Guatemala, Costa Rica, Colombia, Venezuela, Bolivia, C Chile, and Uruguay.    

Patagonia Apocynaceae Genera

Apocynoideae in Patagonia

Elytropus monospecific endemic to C & S Chile and S Argentina. 

Asclepiadoideae in Patagonia

Araujia 1 sp native to S Argentina; Asclepias 1 sp. native to S Argentina; Diplolepis 10 spp. S SAM endemic genus native to SC+S Chile and S Argentina, including 5 narrow endemics; Philibertia 1 sp. SAM endemic genus native to C Chile and S Argentina; Tweedia 2 spp. S SAM endemic genus native to C Chile and S Argentina. 

Additional Information and References

• Visit Lyrae’s Dictionary of Botanical Terms to learn the terminology of botanists. Note that if you hover over most of the words in the articles, you can also get definitions from them there.
• Willis, Lyrae (Unpublished). Plant Families of North America. This is where all of the family descriptions come from. Below should be most of my references for this, as well as my own personal observations.
• Canadensys: Acadia University, Université de Montréal Biodiversity Centre, University of Toronto Mississauga, University of British Columbia. http://data.canadensys.net/explorer (accessed 2020 – current)
• Delta: Watson, L., and Dallwitz, M.J. (1992+). The Families of Flowering Plants: descriptions, illustrations, identification, and information retrieval. Version: 2nd May 2020. delta-intkey.com. Accessed spring through fall of 2020.
• Endress, Mary & Liede-Schumann, Sigrid & Meve, Ulrich. (2014). An updated classification for Apocynaceae. Phytotaxa. 159. 10.5167/uzh-93115.
• GBIF.org (2020), GBIF Home Page. Available from: https://www.gbif.org
• Flora of North America (1993+). https://floranorthamerica.org/Main_Page.
• Naturalista: CONABIO http://www.naturalista.mx (Accessed 2020–current).
• Neotropikey: Milliken, W., Klitgård, B., & Baracat, A. eds. (2009+). Neotropikey: Interactive key and information resources for flowering plants of the Neotropics. www.kew.org/neotropikey.com (accessed 2020 – current).
• Patagonia Wildflowers: Wildflower Identification Site. https://patagoniawildflowers.org/ Accessed throughout the fall of 2020.
• POWO (2019). Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet: http://www.plantsoftheworldonline.org/
• Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 14, July 2017 [more or less continuously updated since]. http://www.mobot.org/MOBOT/research/APweb/
• USDA, NRCS. 2020. The PLANTS Database (http://plants.usda.gov, 2 June 2020). National Plant Data Team, Greensboro, NC, USA; accessed throughout the fall of 2020.
• WFO (2022): World Flora Online. Published on the Internet: http://www.worldfloraonline.org. Accessed Spring 2022 – current.

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I am currently seeking funding to expand my website and SEO capabilities as I keep adding new families, and I am also looking to invest in a new macro lens, as I will soon be adding floral dissections to the families as they become available to me. You can donate to help support native plant education using the GoFundMe link, also at the bottom of the page.

Copyright Information

The information and the photos on this site are free to use for educational purposes, with proper attribution. For other uses, please contact me first.

You can cite this site as follows: Willis, Lyrae (2020+). Lyrae’s Nature Blog – Plant Families of North America. https://lyraenatureblog.com/. Accessed [Enter Date].