Introduction to the Acanthaceae Family

The Acanthaceae family is part of the Lamiales order of core eudicots and, as such, is closely related to the Lamiaceae or Mint family, with which it shares several characteristics. The Acanthaceae are widespread in tropical and subtropical regions, but the USA has quite a few, and they can even be found in temperate Canada. Acanthaceae are usually herbs or shrubs and typically have zygomorphic flowers in white, pink, blue, and shades of purple. Several species are used ornamentally and medicinally. In the field, if you are injured, you can crush the leaves of most Acanthaceae and apply them directly to the wounds to aid in healing. 

Flowers of the Acanthaceae

Plants are always hermaphrodites. Pollination is entomophilous, and the mechanism may be conspicuously specialized or not. Flowers are aggregated in racemes, cymes, or verticils. Often they are in dichasial cymes that become monochasial in the ultimate branches and are often condensed in the leaf axils. Flowers may or may not be pseudanthial. Flowers are both bracteate and bracteolate, and the bracts and bracteoles are often large and showy. Bracts are absent in Thunbergioideae, but bracteoles are present, and bracts are present, but bracteoles are absent in the Nelsonioideae. Flowers are usually more or less zygomorphic or sometimes actinomorphic. The floral irregularity involves the perianth and the androecium. Flowers are 4 or 5 merous and are tetracyclic. Free hypanthium is absent. A hypogynous disk is present. Perianth has a distinct calyx and corolla with 8(6–7) or 10 parts in 2 whorls and may be isomerous or anisomerous. Calyx has 4(3) or 5 parts in 1 whorl, is connate, and is variously entire, lobulate, or blunt-lobed, with the lobes shorter or longer than the tube. Varying degrees of gamosepaly from 0.5–0.9. The calyx may be imbricate, valvate, contorted, or open in bud. When the calyx has 5 parts, it is free with the median member posterior. Corolla has 4 or 5 parts, or 3 parts when the upper lip is suppressed. It is 1 whorled and connate, at least basally. The corolla tube is adaxially deeply split in Acanthus and others, where the upper lip of the corolla is cut away almost to the base of the tube. Corolla lobes may be shorter to longer than the tube. The degree of gamopetaly is 0.5–0.75. The corolla is imbricate ascending cochlear or quincuncial, contorted (left or right), or sometimes with open aestivation (Acanthus). It may be bilabiate, unequal but not bilabiate, with the upper lip at times suppressed, or maybe almost regular.  

Androecium of the Acanthaceae

The androecium has 2 or 4(5) members. Androecial members are adnate with the filaments usually inserted on the corolla tube. They may be all equal or unequal, free of one another or coherent 2 adelphous (partially connate in pairs), and are 1 whorled. Androecium usually includes staminodes or may be made of exclusively fertile stamens (rarely Ruellia).  When present, there are 1-3 staminodes in the same series as the fertile stamens. There are 4(5) or 2 stamens that usually extend beyond the mouth of the flower and are inserted near the base, midway down, or in the throat of the corolla tube, and they are usually didynamous and may or may not be hairy or spurred. Stamens are always oppositisepalous, alternating with the corolla members. Anthers may be separate from one another or connivent, are dorsifixed (often with one lobe reduced or abortive) or adnate, dehiscing via longitudinal slits, are unilocular to bilocular, are tetrasporangiate, and may or may not be appendaged (often with a long connective).

Gynoecium of the Acanthaceae

The gynoecium is 2-carpelled, and the pistil is 2-celled. The gynoecium is synstylovarious to syncarpous and superior. The ovary is 2 locular and sessile. The gynoecium is median. There is one style that is attenuate from the ovary, apical, and usually filiform and much longer than the ovary. There are two stigmas with the posterior often smaller, they are dry type (wet in Thunbergioideae), non-papillate (papillate in Thunbergioideae), and Group II type.  Placentation is axile. Each locule contains 2-50 ovules that are non-arillate or arillate (occasionally with funicular aril), anatropous to campylotropous, and unitegmic.  

Fruit of the Acanthaceae

Fruit is a non-fleshy 2-chambered loculicidal capsule dehiscing somewhat explosively, or sometimes an achene (Avicennia). In most species, the seeds are attached to a small hooked stalk that ejects them from the capsule. Seeds are non-endospermic, borne on retinacula, may or may not be conspicuously hairy, and may or may not contain amyloid.

Habit & Leaf Form of the Acanthaceae

Mostly tropical herbs, shrubs, or twining vines, with some epiphytes or rarely trees (with pneumatophores and sometimes stilt roots in Avicennia). Leaves are usually well developed but sometimes are much reduced, or occasionally plants are aphyllous switch-plants. Leaves may be heterophyllous or isophyllous and are often swollen at the nodes. Branches are terete to angular in cross-section. Herbs are annual or perennial, with or without a basal aggregation of leaves. Most plants are self-supporting but may also be epiphytic or climbing (sometimes in Adhatoda). When they climb, they are stem twiners, root climbers, or scrambling with twiners twining clockwise.  Tree forms are always leptocaul. Plants may be hydrophytic, helophytic (including a few mangroves), mesophytic (many from damp tropical forests), or xerophytic. Leaves are arranged opposite distichous or decussate (rarely alternate or whorled), are simple, and may or may not be gland-dotted. Lamina is dissected or entire, pinnately veined, and cross-venulate. Leaves are exstipulate. Lamina margins are entire, crenate, serrate, or dentate and may be flat, revolute, or involute. Domatia occur in 3 genera as hair tufts. The leaf lamina is dorsiventral (sometimes incomplete) or bifacial (isobilateral in several genera), with or without epidermal salt glands (present on both leaf surfaces in Acanthus ilicifolius). The abaxial epidermis may be papillose or not. Stomata are almost always diacytic, but in Lepidagathis, they are paracytic. Stomata are mainly confined to the abaxial surface or sometimes found on both surfaces. Hairs of diverse kinds are present throughout the family and are usually small and short-stalked and may be eglandular unicellular, uniseriate, or glandular (may always be glandular in Nelsonioideae). Unicellular and multicellular hairs are branched or simple. Lamina does not have secretory cavities. Cystoliths are very often present as streaks in the lamina but are absent in Acantheae and Aphelandreae.In numerous genera, the mesophyll has sclerenchymatous idioblasts as bundles of unique acicular fibers.

Uses of Acanthaceae 

The leaves of many Acanthaceae are used externally for wounds. Research has shown that the family has antifungal, anti-inflammatory, anti-pyretic, antioxidant, insecticidal, immunomodulatory, anti-platelet aggregation, and anti-viral potential. More research is currently underway. Notable ornamentals include bear’s-breech (Acanthus mollis), clockvine (Thunbergia), shrimp plant (Justicia brandegeana), and caricature-plant (Graptophyllum pictum).

Morphology of Acanthaceae in North America

Acanthaceae Species I have Covered So Far in North America

Acanthoideae Subfamily

Acanthus mollis – Bear’s Breeches

A clump-forming perennial herb with tuberous roots, a basal rosette of deeply lobed leaves, and tall spikes of pinkish or purplish flowers. Native to the Mediterranean, often cultivated in North America for its leaves and flowers.

Carlowrightia arizonica – Arizona Wrightwort

Heavily branched subshrub 10 – 30 cm tall or sometimes taller. Leaves are simple, opposite, variable in size and shape but ~ lanceolate. Flowers are narrowly triangular with 2 lateral petal lobes, 2 upper lobes fused together with a yellow spot and purple streaks, and a keeled bottom lobe. Native to Texas, Arizona, California, and northern Mexico.

Dicliptera resupinata – Arizona Foldwing

Erect herb to 60 cm tall with heavily branching pubescent stems; leaves are lanceolate 2 – 6 cm long. Flowers are bilabiate, light purple with small dark purple lines near the center and surrounded by two heart shape bracts. Native to southeastern AZ, southwest NM, USA, & northwest Mexico.

Justicia pilosella – Hairy Tubetongue

Herbaceous perennial to 30 cm tall with opposite leaves that may be pubescent or glabrous but with ciliate margins, zygomorphic sessile flowers with a long, white, pubescent tubular corolla with 4 pink or purple lobes, 3 of which bend outwards strongly. Narrow endemic of southern TX and southern NM in the USA, plus arid northeastern Mexico.

Ruellia blechum – Green Shrimp Plant

Short herbaceous erect or clambering perennial with opposite ovate leaves and a conspicuously pyramidal shaped inflorescence with often pilose pyramidal bracts from Paco’s Nature Reserve, Sinaloa, Mexico; conspicuous inflorescence spike with pyramidal bracts. Native to Mexico, Central & South America.

Ruellia caroliniensis – Carolina Wild Petunia

Unbranched herbaceous perennial to 1 m with opposite, oval leaves and sessile axillary clusters of 2 – 4 flowers with usually only 1 – 2 open at a time; leaves and flowers crowded together at top of plant. Flowers are light purple to pinkish with a slender corolla tube and 5 petaloid lobes, and long-pointed calyx lobes. Native throughout the eastern USA.

Ruellia humilis – Wild Petunia

Perennial herb to 60 cm tall with tubular, bell-shaped flowers with a long, skinny white tube and five shallow rounded lavender to lilac-colored petals; singly or in clusters in upper axils, not crowded at the top of the plant. Native to eastern and central USA.

Ruellia nudiflora – Violet Wild Petunia

Erect 30 – 60 cm tall perennial with few branches and opposite gray-green leaves 5 – 12 cm long with undulate or wavy-toothed margins on short petioles. Terminal dichasial inflorescence of lavender to purple trumpet-shaped flowers with inserted stamens. Flowers last about a day. Native to southern USA (AZ east to AL), Mexico, and Central America.

Ruellia strepens – Smooth Wild Petunia

Herbaceous perennial plant 0.5 – 1 m tall, sometimes branching with hairless or parsley hairy stems; opposite leaves up to 13 cm long, lanceolate to ovate and smooth or slightly undulate margins and mostly hairless surfaces. Nearly sessile flowers in clusters of 1 – 3 in upper axils. Native to southcentral & southeast USA.

Tetramerium nervosum – Hairy Fournwort

Subshrub to 30 cm tall with opposite lanceolate leaves. Flowers in conspicuous pilose leafy bracts on hairy, 4-sided spike inflorescences; tubular with an upper lobe with a violet patch and a yellow base, 2 side lobes, and a keel-like lower lobe. Native to AZ and TX, USA south through Mexico, Central America, south to Venezuela.

Nelsonioideae Subfamily

Elytraria imbricata – Purple Scaly Stem

Weedy subshrub with linear leaves crowded at the top of the plant that may be basal and stemless or up to 60 cm tall. Inflorescences with very appressed bracts, blue flowers. Native from southern USA south to north Argentina, mostly dry tropical forests.

Thunbergioideae Subfamily

Thunbergia grandiflora – Blue Trumpet Vine

Twining evergreen vine 2 – 2.5 m long, with large, heart-shaped, bright green leaves and large showy lavender-blue trumpet-shaped flowers up to 7 cm across with a yellow or white throat. Native throughout southeast Asia. Often cultivated as an annual in North America.

Taxonomy of Acanthaceae

The Acanthaceae family has between 4000-5600 spp in 207 currently accepted genera. It is part of the Lamiales order of the Core Eudicots. Some genera and species are as of yet unconfirmed, so these numbers may change. There are four subfamilies of Acanthaceae recognized:

1. Acanthoideae – herbs or sometimes shrubs, with petiole bundles arranged in a circle. Corolla often has the abaxial lobe outside others when in bud. Anthers are sagittate, or the thecae are displaced and not opposite, sometimes with one theca more or less reduced. Stigma is dry and typically bifid. Capsules are obovoid and explosive, seeds are flattened and borne on hook-like hardened funicles. 
2. Avicennioideae – trees with pneumatophores, sometimes stilt roots. The leaf lamina is thick with salt glands on both sides, club-shaped hairs, and colleters.  Flowers are 4(-6) merous, quincuncial, with nectar glands on the inside of the tube. Stamens are equal and alternate with the corolla. Stigma has two blunt lobes. Fruit is an achene with large seeds that are more or less viviparous. 
3. Nelsonioideae – herbs with glandular hairs. The inflorescence may be terminal or axillary, bracts are spiral, and bracteoles are sometimes absent. Corolla with descending cochleate aestivation with the adaxial lobes of outside the others. There are 2 stamens with variable anthers with thecae that may or may not be separate. The stigma is broadly lobed. 
4. Thunbergioideae – twining vines, sometimes erect. Petiole bundles are arcuate or annular with wing bundles. Leaf lamina vernation is strongly curved. Inflorescence is axillary flowers or fasciculate. They have no bracts but have very large bracteoles that may or may not be connate. Anthers have lignified unicellular hairs, are sagittate, dehisce by pores or sometimes slits, and have an elongated connective. The stigma is small, wet, sub-bilobed to trumpet-shaped, and has broad and often unequal papillate lobes.

Genera:

Acanthoideae: Acanthopale (12), Acanthopsis (19), Acanthus (30-39), Achyrocalyx (4), Afrofittonia (1), Ambongia (1), Ancistranthus (1), Andrographis (26), Angkalanthus (1), Anisacanthus (13), Anisosepalum (3), Anisostachya (61 inc Corymbostachys), Anisotes (30 inc Chlamydostachya, Danguya, Himantochilus), Aphanosperma (1), Aphelandra (199 inc Geissomeria), Ascotheca (1), Asystasia (55 inc Styasasia, Asystasiella), Ballochia (3), Barleria (286), Barleriola (4), Blepharis (126), Borneacanthus (6), Boutonia (1), Brachystephanus (21 inc Oreacanthus), Bravaisia (3), Brillantaisia (14), Brunoniella (6), Calacanthus (1), Calycacanthus (1), Camarotea (1), Carlowrightia (27), Celerina (1), Cephalacanthus (1), Cephalophis (1), Chalarothyrsus (1), Chamaeranthemum (5), Champluviera (2), Chileranthemum (3), Chlamydacanthus (3), Chlamydocardia (2), Chorisochora (4), Chroesthes (3), Clinacanthus (4), Clistax (3), Codonacanthus (3), Conocalyx (1), Cosmianthemum (13), Crabbea (13 inc Acanthostelma, Golaea), Crossandra (54), Crossandrella (3), Cuenotia (1), Cyclacanthus (2), Cynarospermum (1), Cyphacanthus (1), Dasytropis (1), Dianthera (41 inc Centrilla, Rhacodiscus), Diceratotheca (1), Dichazothece (1), Dicladanthera (2), Dicliptera (216 inc Dactylostegium, Peristrophe), Dinteracanthus (5), Dischistocalyx (12), Duosperma (26), Dyschoriste (94 inc Sautiera, Apassalus, Chaetacanthus), Ecbolium (22), Echinacanthus (4), Encephalosphaera (3), Eranthemum (22), Eremomastax (1), Filetia (9), Fittonia (2), Forcipella (6), Glossochilus (1), Graphandra (1), Graptophyllum (15), Gymnophragma (1), Gymnostachyum (50), Gypsacanthus (1), Haplanthodes (3), Haplanthus (4), Harpochilus (2), Hemigraphis (38), Henrya (3), Herpetacanthus (21 inc Juruasia, Standleyacanthus), Heteradelphia (2), Holographis (17), Hoverdenia (1), Hulemacanthus (2), Hygrophila (78 inc Hemiadelphis, Nomaphila, Santapaua, Synnema), Hypoestes (138 inc Periestes), Ichthyostoma (1), Isoglossa (70 inc Rhytiglossa), Isotheca (1), Jadunia (2), Justicia (935 inc Adhatoda, Beloperone, Calophanoides, Drejerella, Ixtlania, Jacobinia, Leptostachya, Mananthes, Megalostoma, Neohallia, Odontonemella, Pelecostemon, Pupilla, Sarojusticia, Sarotheca, Sericographis, Siphonoglossa), Kalbreyeriella (4), Kenyacanthus (1), Kosmosiphon (1), Kudoacanthus (1), Lankesteria (7), Lasiocladus (4 inc Synchoriste), Leandriella (2), Lepidagathis (142 – 157 inc Acanthura, Lindauea, Lophostachys, Teliostachya), Leptosiphonium (10), Liberatia (2), Linariantha (1), Louteridium (11), Mackaya (6 inc Odontonemella),  Marcania (1), Megalochlamys (10), Megaskepasma (1 inc Perenideboles), Melittacanthus (1), Mellera (8 inc Ionacanthus), Metarungia (1), Mexacanthus (1), Mimulopsis (18 inc Epiclastopelma), Mirandea (6), Monechma (14 inc Schwabea), Monothecium (3), Morsacanthus (1), Neriacanthus (5), Neuracanthus (32), Nicoteba (4), Odontonema (32 inc Phidiasia), Oplonia (21 inc Forsythiopsis), Orophochilus (1), Pachystachys (18), Pararuellia (11), Pericalypta (1), Petalidium (38), Phaulopsis (21 inc Theileamea), Phialacanthus (5), Phlogacanthus (42 inc Cystacanthus), Physacanthus (3 inc Haselhoffia), Podorungia (5 inc Warpuria), Poikilacanthus (13), Polylychnis (1), Populina (2), Pranceacanthus (1), Pseudacanthopale (1), Pseuderanthemum (128 inc Buceragenia), Pseudodicliptera (4), Psilanthele (1), Psiloesthes (1), Ptyssiglottis (37), Pulchranthus (4), Rhaphidospora (8), Rhinacanthus (25), Rhombochlamys (1), Ritonia (3), Rostellularia (29), Ruellia (361 inc Benoicanthus, Blechum, Dipteracanthus, Eusiphon, Lychniothyrsus, Nothoruellia, Pentstemonacanthus, Pseudoruellia, Spirostigma, Stephanophysum, Tremacanthus, Ulleria), Ruelliopsis (1), Rungia (81), Ruspolia (4), Ruttya (6), Saintpauliopsis (1), Salpinctium (3), Salpixantha (1), Samuelssonia (1), Sanchezia (55 inc Steirosanchezia), Sapphoa (2), Satanocrater (4), Schaueria (15), Schaueriopsis (1), Sclerochiton (18), Sebastiano-schaueria (1), Spathacanthus (4), Sphacanthus (2), Sphinctacanthus (2), Stachyacanthus (1), Stenandrium (66 inc Stenandriopsis), Stenostephanus (81 inc Cylindrosolenium,  Habracanthus, Hansteinia, Kalbreyeracanthus, Lissospermum, Listrobanthes, Nilgirianthus, Razisea), Stenothyrsus (1), Streblacanthus (3 inc Sciaphyllum), Streptosiphon (1), Strobilanthes (448 inc Championella, Clarkeasia, Didyplosandra, Hemigraphis, Hymenochlaena,  Microstrobilus, Pachystrobilus, Paragutzlaffia, Parastrobilanthes, Pleocaulus, Psacadopaepale, Pseudostenosiphonium, Pteracanthus, Pteroptychia, Semnothyrsus, Sericocalyx, Taeniandra, Tarphochlamys, Tetraglochidium, Thelepaepale, Triaenanthus, Xanthostachya, Xenacanthus), Strobilanthopsis (1), Suessenguthia (8), Symplectochilus (2), Tabascina (1), Tessmanniacanthus (1), Tetramerium (30), Thyrsacanthus (6 inc Drejera), Thysanostigma (2), Trichanthera (2), Trichaulax (1), Trichocalyx (2), Trichosanchezia (1), Vindasia (1), Whitfieldia (14), Wuacanthus (1), Xantheranthemum (1), Xerothamnella (2), Xylacanthus (1), Yeatesia (3), Zygoruellia (1). Avicennioideae: Avicennia (8). Nelsonioideae: Aymoreana (?), Elytraria (21), Nelsonia (3), Staurogyne (149 inc Gynocraterium, Ophiorrhiziphyllon, Staurogynopsis).  Thunbergioideae: Anomacanthus (1), Mendoncia (89), Pseudocalyx (6), Thunbergia (151).

Key Differences From Similar Families

Acanthaceae are most often confused with Lamiaceae or Verbenaceae. Both the Lamiaceae and Verbenaceae usually have squarish stems as opposed to terete or angular, and their leaf nodes are not swollen. Acanthaceae has bracteoles not seen in the other two families, and their stamens are often hairy or spurred. Acanthaceae fruits are dry capsules that are often forcibly ejected as opposed to nutlets in Lamiaceae or drupes or berries in Verbenaceae. 

Distribution of Acanthaceae

Acanthanceae are mostly tropical and subtropical species, with a few temperate outliers. Native throughout Africa, Australia, Indonesia, and the Americas. 

Distribution of Acanthaceae in the Americas

Canadian Genera Include:

Acanthoideae: Dianthera 1 of 41 former Americas endemic spp native ON, QC; Justica 1 sp native in QC and ON. 

USA Genera Include:

Acanthoideae: Acanthus 1 of 30 Old World Tropics spp intro CA; Andrographis 1 of 26 Indian & S Asia spp intro VA; Anisacanthus 4 of 13 Americas endemic spp native to AZ, NM, TX; Asystasia 1 of 55 Old World Tropics spp intro FL, AL?; Barleria 2 of 286 pantropical spp intro FL; Carlowrightia 8 of 27 Americas endemic spp native CA, AZ, NM, TX, intro FL; Dianthera 9 of 41 former Americas endemic spp inc 8 native and 1 intro AZ, KS S to TX and all E to NJ and S to FL from there plus IA, MI, NY, VT, genus now intro Africa, Malaya; Dicliptera 4 of 216 pantropical spp native to S half of USA from AZ E to NC and all S plus KS, MO, IL, IN, KY, VA; Dyschoriste 6 of 94 pantropical spp native to NM, AZ, TX, LA, OK, FL, AL, GA, SC; Eranthemum 1 of 22 S Asia spp intro FL; Graptophyllum 1 of 15 African sp intro FL; Hemigraphis 2 of 38 tropical Asia spp intro LA, FL; Henrya 1 of 3 Americas endemic spp native AZ; Hygrophila 6 of 78 pantropical spp native and intro TX, LA, AL, MS, GA, FL, VA, inc 1 sp formerly known as Nomaphila intro TX; Hypoestes 1 of 138 Old World Tropics spp intro HI; Justicia 19 of 935 pantropical spp native and intro in most of S half USA CA E to NJ and all S exc NV, UT, CO and inc IA, WI, MI, NY, VT;  Megaskepasma monospecific former N SAM endemic inro HI; Odontonema 2 of 32 mostly Americas endemic spp intro FL; Pseuderanthemum 1 of 128 pantropical spp intro FL, SC; Ruellia 22 of 361 mostly pantropical spp native in most of E half USA from ND S to TX and all E exc ND, SD, CT, RI, MA, VT, NH, ME and inc AZ, NM, but intro in AK, NY; Sanchezia 1 of 55 former Neo endemic spp intro HI; Stenandrium 2 of 66 Americas & African spp native NM, TX, FL, GA; Tetramerium 1 of 30 sub & tropical Americas endemic spp native NM, AZ, TX; Yeatesia 2 of 3 SE NAM endemic spp native TX, LA, AL, MS, FL, GA. Avicennioideae: Avicennia 2 of 8 pantropical spp native TX, MS, AL, GA, LA, FL, intro CA. Nelsonioideae: Elytraria 3 of 21 pantropical spp native NM, AZ, TX, FL, GA, SC, inc 1 narrow endemic of GA, FL, SC; Nelsonia 1 of 3 Old World Tropics spp intro FL. Thunbergioideae: Thunbergia 5 of 151 Old World Tropics spp intro TX, FL and HI. 

Mexico Genera Include:

Acanthoideae: Acanthus 1 of 30 Old World Tropics spp intro Pue; Andrographis ?? of 26 Indian & S Asia spp intro Pue, Tlx, Mor, Ver; Anisacanthus 7 of 13 Americas endemic spp native throughout all of Mexico, inc 3 endemic to Mexico inc 1 a narrow endemic of Son + Chi; Aphanosperma sinaloensis monospecific endemic BC, BCS, Son, Sin, Chi, Dgo, Zac, NL, Tam; Aphelandra ?? of 199 former Mexico & Neo endemic spp native throughout all of Mexico; Barleria ?? of 286 pantropical spp native most of Mexico exc BC, BCS, Son, Sin; Bravaisia 3 of 3 Mexico + N Neo endemic spp native much of Mexico exc BC, BCS, Son, Sin; Carlowrightia 26 of 27 Americas endemic spp native through all of Mexico inc 15 endemics of Mexico, 7 of which are narrow endemics of Tam (3), Chi (2), Sin (1), Yuc (1); Chalarothyrsus monospecific endemic of Nay, Jal, Col, Mch, Gro, Oax, Pue; Chileranthemum 3 of 3 spp native most of Mexico exc BC, BCS, Son, Sin, inc 1 narrow endemic of Jal + Gro; Dianthera ?? of 41 former Americas endemic spp native throughout all of Mexico, genus now intro Africa, Malaya; Dicliptera ?? of 216 pantropical spp native all of Mexico; Dyschoriste ?? of 94 pantropical spp native throughout all of Mexico; Gypsacanthus monospecific endemic of Nay, Jal, Col, Mch, Gro, Oax, Pue; Henrya 3 of 3 Americas endemic spp native in all of Mexico, inc 2 endemic to S+W Mexico; Holographis 17 of 17 spp endemic throughout all of Mexico; Hoverdenia monospecific endemic of Chi, Coa, NL, SLP, Dgo, Zac, Ver; Hygrophila ?? of 78 pantropical spp native Nay, Jal, Col, Mch, Gro, Oax, Chp, Ver, Yuc, QR, Cam, Tab; Hypoestes 1 of 138 Old World Tropics spp intro much of Mexico exc BC, BCS, Son, Sin, Cam, Tab, Chp, Yuc, QR; Justicia 20+ of 935 pantropical spp native throughout all of Mexico;  Lepidagathis ?? of 142 pantropical spp native Nay, Jal, Col, Gro, Mch, Oax, Chp, Pue, Mor, Ver, Cam, Tab, Yuc, QR; Louteridium 9 of 11 Mexico + Neo endemic spp native most of Mexico exc BC, BCS, Son, Sin, inc 6 narrow endemics of Mch (1), Oax (1), Jal + Mch (1), Ver + Chp (1), Gro (1), Tam (1); Mexacanthus monospecific endemic Nay, Jal, Col, Mch, Gro, Oax; Mirandea 6 of 6 Mexico endemic spp native most of Mexico exc Pue, BC, BCS, Son, Sin; Odontonema ?? of 32 mostly Americas endemic spp native in all of Mexico; Pachystachys 1 of 18 Neo endemic spp native Chp, Cam, Tab, QR, Yuc, intro Nay, Jal, Col, Gro, Mch, Oax; Poikilacanthus 5 of 13 Neo endemic spp native Nay, Jal, Col, Mch, Gro, Oax, Chp, Pue, Tab, Cam, Yuc, QR, inc 4 endemic to Mexico, 3 of which are narrow endemics of Oax (1), Col + Mch + Oax (1); Pseuderanthemum ?? of 128 pantropical spp native throughout all of Mexico; Ruellia ?? of 361 mostly pantropical spp native throughout all of Mexico; Sanchezia ?? of 55 former Neo endemic spp intro Chp, Tab, Cam, Yuc, QR; Spathacanthus 3 of 4 Mexico + CAM endemic spp native Nay, Jal, Col, Mch, Gro, Pue, Ver, Chp, Tab, Cam, Yuc, QR, inc 1 narrow endemic of Ver; Stenostephanus ?? of 81 Mexico & Neo endemic spp native most of Mexico exc BC, Son, Sin; Streblacanthus 2 of 3 Mexico & N Neo endemic spp native Nay, Jal, Col, Mch, Gro, Oax, Ver; Tabascina monospecific endemic Chp, Tab, Cam, Yuc, QR; Tetramerium 25 of 30 sub & tropical Americas spp native in all of Mexico, inc 21 endemics of Mexico, 10 of which are narrow endemics of Oax (3), Mch (2), Gro (2), Oax + Chp (1), Jal + Col (1), Sin (1); Yeatesia 3 of 3 SE NAM endemic spp native Chi, Coa, NL, Tam, Dgo, Zac, SLP, Hgo, Mex?, inc 1 endemic of NE Mexico.  Avicennioideae: Avicennia 2 of 8 pantropical spp native most of Mexico exc C Mexico. Nelsonioideae: Elytraria 4 of 21 pantropical spp native all of Mexico inc Mexican Pacific Is, inc 2 endemics to Mexico; Nelsonia 1 of 3 Old World Tropics spp intro Nay, Jal, Col, Gro, Mch, Oax; Staurogyne ?? of 149 pantropical spp native Nay, Jal, Col, Mch, Gro, Oax; Stenandrium ?? of 66 Americas & African spp native throughout all of Mexico. Thunbergioideae: Mendoncia ?? of 89 Americas and Africa spp native Nay, Jal, Col, Mch, Gro, Oax, Chp, Ver, Tab, Cam, Yuc, QR; Thunbergia ?? of 151 Old World Tropics spp intro much of Mexico exc BC, BCS, Son, Sin.

Neotropical Genera Include:

Acanthoideae: Ancistranthus monospecific endemic of Cuba; Andrographis ?? of 26 Indian & S Asia spp intro Bahamas, Cuba, Hispaniola, Leeward & Windward Is;Anisacanthus 6 of 13 Americas endemic spp native El Salvador, Honduras, Nicaragua, Costa Rica, E Brazil, inc 5 narrow endemics of Nicaragua (1), Costa Rica (1), E Brazil (3); Aphelandra 199 of 199 former Mexico & Neo endemic spp native Mexico S through CAM, Trinidad-Tobago, tropical SAM S to Peru, N Argentina exc N Chile, Paraguay, Uruguay, intro in Cuba, Dominican Republic, Windward Is, & S Asia; Asystasia 2 of 55 Old World Tropics spp inc 1 sp endemic to Panama (the only New World native sp) and 1 sp intro Belize, El Salvador, Honduras, Nicaragua, Antilles (exc Netherlands Antilles), Venezuela, SE Brazil; Barleria ?? of 286 pantropical spp native CAM, Colombia, Venezuela, Guyana, intro Bahamas, Antilles (exc Cayman Is), SW Caribbean, Trinidad-Tobago, French Guiana, S Brazil; Barleriola 4 of 4 Greater Antilles endemic spp of Cuba, Dominican Republic, Haiti, Puerto Rico; Bravaisia 3 of 3 spp Mexico & N Neo endemic spp native CAM, Cuba, Colombia, Venezuela, Trinidad-Tobago, intro Venezuelan Antilles, Windward Is; Brillantaisia 1 of 14 African spp intro Jamaica; Carlowrightia 4 of 27 Americas endemic spp native CAM (exc Panama), Ecuador, inc 1 narrow endemic of Ecuador;Cephalacanthus monospecific endemic of Peru; Chamaeranthemum 5 of 5 Neo endemic spp of Costa Rica, Peru, SE+S Brazil, inc 4 narrow endemics of Costa RIca (2), Rio de Janeiro SE Brazil (1), Santa Catarina S Brazil (1); Chileranthemum 2 of 3 Mexico + CAM endemic spp native Guatemala, El Salvador; Clistax 3 of 3 spp endemic to N+E+S Brazil;Crossandra 1 of 54 African + Indian spp intro Antilles (exc Cayman Is, Netherlands Antilles), El Salvador, Nicaragua; Cuenotia monospecific endemic NE Brazil; Cyphacanthus monospecific endemic Colombia; Dasytropis monospecific endemic Cuba; Dianthera 41 of 41 former Americas endemic spp native E Canada & USA S through Mexico, CAM, Antilles (exc Cayman Is & Netherland Antilles), and S through tropical SAM S to N Argentina (exc N Chile), intro Bermuda, Africa, Malaya; Dichazothece monospecific endemic SE Brazil; Dicliptera ?? of 216 pantropical spp native CAM, Bahamas, Turks-Caicos, Greater Antilles (exc Cayman Is), Leeward & Windward Is, Trinidad-Tobago, tropical SAM S to N Chile, N Argentina; Dyschoriste ?? of 94 pantropical spp native CAM (exc Belize), Cuba, Hispaniola, Venezuela, Ecuador, Peru, Bolivia, Paraguay, C+S+SE Brazil, N Argentina, Uruguay, intro Leeward Is; Encephalosphaera 3 of 3 N SAM spp endemic spp of Colombia, Ecuador, Peru, N Brazil; Eranthemum 1 of 22 S Asia spp intro El Salvador, Antilles (exc Puerto Rico, Netherlands Antilles, Cayman Is), Trinidad-Tobago, Suriname;Fittonia 2 of 2 former N SAM endemic spp native Colombia, Venezuela, Ecuador, Peru, Bolivia, N Brazil and intro El Salvador, Myanmar, Bangladesh; Graptophyllum 1 of 15 African spp intro Cuba, Hispaniola, Puerto RIco, Jamaica, Leeward Is, Venezuelan Antilles, Trinidad-Tobago, Honduras, Nicaragua, Panama, Venezuela; Harpochilus 2 of 2 spp endemic to NE Brazil; Henrya 1 of 3 Americas endemic spp native CAM (exc Belize); Herpetacanthus 21 of 21 Neo endemic spp native Costa Rica, Honduras, Nicaragua, Panama, Ecuador, French Guiana, Suriname, Peru, Bolivia, N+E Brazil; Hygrophila ?? of 78 pantropical spp native Greater Antilles (exc Cayman Is), Trinidad-Tobago, CAM (exc Costa Rica), tropical SAM S to N Argentina (exc N Chile);Hypoestes 1 of 138 Old World Tropics spp intro Mexico, Guatemala, El Salvador, Honduras, Panama, Colombia, Paraguay;Isotheca monospecific endemic Venezuela and Trinidad-Tobago; Justicia ?? of 935 pantropical spp native widespread CAM, Greater Antilles (exc Cayman Is), Leeward & Windward Is, Trinidad-Tobago, tropical SAM S to N Argentina (exc N Chile); Kalbreyeriella 4 of 4 Neo endemic spp native Costa Rica, Panama, Colombia, N Brazil, Ecuador, Peru; Lepidagathis ?? of 142 pantropical many CAM, Cuba, Hispaniola, Puerto Rico, Leeward & Windward Is, Trinidad-Tobago, tropical SAM S to Peru, NW Argentina, Paraguay, S Brazil; Liberatia 2 of 2 SAM endemic spp of Bolivia, SE+S Brazil; Louteridium 5 of 11 Mexico & Neo spp endemic spp native CAM (exc El Salvador), inc 1 narrow endemic of Belize; Megaskepasma monospecific former N SAM endemic of Suriname, Venezuela, now intro in Costa Rica, Nicaragua, Panama, Trinidad-Tobago and Hawaii; Morsacanthus monospecific endemic S Brazil; Neriacanthus 5 of 5 Neo endemic spp of Panama, Jamaica, Colombia, Ecuador, Peru, Venezuela; Nicoteba 1 of 4 African spp intro Panama, Colombia, Guyana; Odontonema 32 of 32 spp former Americas endemic spp native from Mexico S through CAM, Cuba, Haiti, Leeward & Windward Is, Trinidad-Tobago, Ecuador, Colombia, Venezuela, N+E Brazil, Guyana, intro Paraguay. Dominican Republic, Puerto Rico, Galapagos as well as Tonga and Samoa; Oplonia 16 of 21 Neo & Madagascar spp native Bahamas, Turks-Caicos, Cuba, Hispaniola, Jamaica, Puerto Rico, Leeward Is, Peru, Bolivia, NW Argentina, inc 13 narrow endemics of Cuba (8), Jamaica (3), Peru (2), 5 spp in genus are endemic to Madagascar; Orophochilus monospecific endemic of Peru; Pachystachys 18 of 18 former Neo endemic spp native Panama, Cuba Lesser Antilles (exc Netherlands Antilles), tropical SAM S to N Argentina (exc Suriname, N CHile, Uruguay), intro SW Mexico, Guatemala, El Salvador, Hispaniola, Puerto Rico and S Asia; Phaulopsis 1 of 21 Old World Tropics spp intro Colombia, Jamaica; Poikilacanthus 9 of 13 Neo endemic spp native Guatemala, Honduras, Nicaragua, Panama, Venezuela, Peru, Bolivia, E+S Brazil, Paraguay, Uruguay, N Argentina, inc 6 narrow endemics of Guatemala (2), Bahia NE Brazil (1), São Paulo SE Brazil (1), Peru (1), Trujillo Venezuela (1); Polylychnis monospecific endemic of Guyana & French Guiana; Pranceacanthus monospecific endemic N+C Brazil, Bolivia?; Pseuderanthemum ?? of 128 pantropical spp native CAM, Colombia, Venezuela, Brazil, Ecuador, Peru, Bolivia, intro Cuba, Puerto Rico, Leeward & Windward Is, Venezuelan Antilles, Trinidad-Tobago;Psilanthele monospecific endemic Ecuador; Pulchranthus 4 of 4 SAM endemic spp of Colombia, Venezuela, N Brazil, Suriname, French Guiana, Ecuador, Peru, Bolivia; Rhombochlamys monospecific endemic Colombia; Ruellia ?? of 361 mostly pantropical spp native CAM, Bahamas, Turks-Caicos, Aruba, Antilles (exc Netherlands Antilles), Trinidad-Tobago, SW Caribbean, Galapagos, tropical SAM S to N Argentina (exc N Chile), inc 1 sp formerly known as Ulleria endemic to Suriname; Ruspolia 1 of 4 African spp intro Trinidad-Tobago; Salpixantha monospecific endemic Jamaica; Samuelssonia  monospecific endemic Haiti; Sanchezia 55 of 55 former Neo endemic spp native Panama, Colombia, Venezuela, N Brazil, Ecuador, Peru, Bolivia, now intro Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica, Antilles (exc Cayman Is, Netherlands Antilles), Trinidad-Tobago, plus Mexico, Hawaii, Africa and Asia;Sapphoa 2 of 2 spp endemic to Cuba; Schaueria 15 of 15 spp formerly endemic to C+E+S Brazil, now intro to Trinidad-Tobago; Sebastiano-schaueria monospecific endemic SE Brazil; Spathacanthus 3 of 4 Mexico & CAM endemic spp native Guatemala, Honduras, Costa Rica, inc 1 narrow endemic of Costa Rica; Stachyacanthus monospecific endemic C Brazil; Stenandrium ?? of 66 Americas & African spp native Guatemala, El Salvador, Honduras, Nicaragua, Bahamas, Turks-Caicos, Cuba, Hispaniola, Puerto Rico, Leeward & Windward Is, tropical SAM S to C Chile, N Argentina (exc Guyana, Suriname, French Guiana, N Chile); Stenostephanus 81 of 81 Mexico & Neo endemic spp native from Mexico S through CAM (exc Belize, El Salvador) to Colombia, Venezuela, N+SE Brazil, Ecuador, Peru, Bolivia; Streblacanthus 3 of 3 Mexico & N Neo endemic spp native Guatemala, Costa Rica, Panama, Peru, N Brazil; Strobilanthes ?? of 448 S + tropical Asia spp intro Belize, El Salvador Honduras, Nicaragua, Panama, Cuba, Hispaniola, Jamaica, Puerto Rico, Windward Is, Venezuelan Antilles, Trinidad-Tobago; Suessenguthia 8 of 8 N SAM endemic spp of N Brazil, Peru, Bolivia;Tessmanniacanthus monospecific endemic Peru; Tetramerium 9 of 30 sub & tropical Americas endemic spp native Guatemala, El Salvador, Honduras, Nicaragua, Panama, Venezuela, Colombia, Ecuador, Peru, Bolivia, inc 5 narrow endemics of Peru; Thyrsacanthus 6 of 6 SAM endemic spp native Venezuela, French Guiana, Guyana, Suriname, Brazil, Bolivia, Paraguay, N Argentina; Trichanthera 2 of 2 Neo endemic spp of Panama, Colombia, Venezuela, N Brazil, Guyana, Suriname, French Guiana, Ecuador, Peru;Trichosanchezia monospecific endemic Peru; Xantheranthemum monospecific endemic Peru. Avicennioideae: Avicennia 3 of 8 pantropical spp native CAM, Bahamas, Aruba, Turks-Caicos, Antilles, SW Caribbean, Trinidad-Tobago, Colombia, Venezuela, Guyana, Suriname, French Guiana, N+E+S Brazil, Uruguay, Ecuador, Peru. Nelsonioideae: Elytraria 11 of 21 pantropical spp native CAM, Cuba, Haiti, Aruba, Trinidad-Tobago, tropical SAM S to Peru, NW Argentina, C+SE Brazil, intro Galapagos, inc 9 narrow endemics of Cuba (6), Haiti (1), Peru (1), Ecuador (1); Nelsonia 1 of 3 Old World Tropics spp intro  El Salvador, Honduras, Nicaragua, Panama, Puerto Rico, Colombia, Ecuador, French Guiana, Bolivia, N+C+E Brazil;Staurogyne ?? of 149 pantropical spp native Nicaragua S to Colombia, Venezuela, Guyana, Suriname, French Suriname, Brazil, Bolivia, Trinidad-Tobago. Thunbergioideae: Mendoncia ?? of 89 Americas & Africa spp native CAM (exc El Salvador), Trinidad-Tobago, tropical SAM S to Peru, Bolivia, Paraguay, S Brazil; Thunbergia ?? several of 151 Old World Tropics spp intro Bahamas, Antilles (exc Cayman Is, Netherlands Antilles), CAM (exc Nicaragua), tropical SAM S to N Argentina (exc French Guiana, N Chile, Uruguay).

Patagonia Genera Include:

Acanthoideae: Stenandrium 1 of 66 Americas & African spp native in Bio Bio C Chile, also in Buenos Aires Argentina just N of Patagonia.

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 (2022).  Plant Families of North America.  Not yet published. This is where all of the family descriptions come from. Below should be most of my references for this. Annonaceae, Orchidaceae, Poaceae, and Cyperaceae have additional references.
• 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 onwards. The families of Flowering Plants: descriptions, illustrations, identification, and information retrieval. Version: 2nd May 2020. delta-intkey.com’. Accessed Spring through fall of 2020.
• GBIF.org (2020), GBIF Home Page. Available from: https://www.gbif.org
• Naturalista: CONABIO http://www.naturalista.mx Accessed 2020 – current.
• Neotropikey: Milliken, W., Klitgård, B. & Baracat, A. eds (2009 onwards). 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/ Retrieved Winter 2020 – current.
• The Plant List (2013). Version 1.1. Published on the Internet; http://www.theplantlist.org/ (accessed 2020 to 2021). No longer updated. Use WFO below.
• USDA, NRCS. 2020. The PLANTS Database (http://plants.usda.gov, 2 June 2020). National Plant Data Team, Greensboro, NC 27401-4901 USA; accessed throughout fall of 2020.
• Wikipedia: The free encyclopedia. (2004, July 22). FL: Wikimedia Foundation, Inc. Retrieved throughout 2019-current, from https://www.wikipedia.org
• WFO (2022): World Flora Online. Published on the Internet; http://www.worldfloraonline.org. Accessed Spring 2022 – current