Introduction to the Campanulaceae Family

The Campanulaceae, or Bellflower family, is part of the Asterales order (related to sunflowers) of the core dicots. It is a widespread family found on every continent except Antarctica, and it is a popular garden ornamental for its lovely flowers. The first time I found one was on a grassy bluff next to the ocean, and I automatically knew what family it was in because of the pretty blue bell-shaped flowers with the long style that the family is best known for, although other colors and flower shapes do exist in the family.

 Common Botanical Description

If you’re new to plant morphology, this guide is a perfect beginner’s description, with no need to know any scientific jargon. Below this section is additional information on uses and morphology photos to help you identify the family, followed by pictures of individual species found in North America. But for researchers or those wanting to learn a more in-depth version, refer to the Scientific Botanical Description below the images for highly detailed scientific descriptions and genus-level distribution data.

Leaves and Stems: Most members are perennial herbs, but some annuals, biennials, shrubs, or small trees exist in the family; mostly they live on land, but some are aquatic. One key identifying feature is the milky juice that is released when they are damaged.

Leaves are usually arranged alternately on the stem but are sometimes in opposite pairs or whorls. They are usually simple (not compound), linear, lance-shaped, oblong, egg-shaped, or rounded with variously toothed margins but are occasionally divided into opposite pairs of leaflets.

Flowers: Flowers are often medium to large and showing, appearing singly or in various spikes or umbrella-shaped clusters. Flowers are typically bell-shaped or star-shaped, giving them the common name of bellflowers. Most are in shades of blue, but they can also be found in white, yellow, red, pink, or purple. Flowers are often symmetrical but can be irregular or “two-lipped,” like in Lobelia.

Reproductive Features: Reproductive features are specialized to ensure successful pollination by insects. There are usually 5 stamens (male parts) that may be separate or joined in a long column surrounding the female parts (ovary, style). Most species have an inferior ovary located below where the petals attach. A single long style comes up through the center of the flower.

Fruits: The fruit is almost always a dry capsule that splits open through valves, irregular slits, or other ways to release the seeds. Very rarely is the fruit a fleshy berry (mostly in the Lobelioideae subfamily). Some seeds are equipped with wings to aid in dispersal.

Uses of the Campanulaceae Family

With plenty of showy flowers, this family is popular for garden ornamentals, especially from Lobelia, Wahlenbergia, Codonopsis, Jasione, and more than 120 species of Campanula. They are widely grown in gardens and landscapes around the world.

Morphology of Campanulaceae in North America

Some Campanulaceae Species of North America

Campanuloideae Subfamily

Campanula alaskana—Alaska Bellflower

Herbaceous perennial from rhizomes with weak stems with larger basal leaves and small, linear stem leaves. Flowers are large and showy, bell-shaped, nodding, and up to 3 cm long in blue-violet to lavender colors. It is often confused with Campanula rotundifolia but has broader leaves, and it is only found along the North Pacific from Washington State north to Alaska.

Campanula petiolata—Western Harebell

This was a recent taxon split from the much more widespread Campanula rotundifolia, with which it shares many characteristics but tends to be more upright with stronger stems. The long style with a 3-lobed tip visible in the photo is common among Campanula rotundifolia and close relatives like these. Some taxonomists do not recognize this or Campanula alaskana as separate species from Campanula rotundifolia.

Campanulastrum americanum—American Bellflower

A tall, erect annual or biennial common in moist woods. Unlike most bellflowers, it has flat star-shaped flowers in elongated spikes, and it has alternate lance-shaped leaves compared to the often linear ones seen in Campanula species.

Triodanis biflora—Venus’s Looking Glass

This species is an annual herb of disturbed areas with alternate leaves that do not wrap around the stem. It has pinkish to purple bellflowers with widely spreading lobes that make them look like a star. Native to the southern and eastern United States, Mexico, and South America.

Triodanis perfoliata—Clasping Venus’s Looking Glass

This species is very similar to Triodanis biflora, with a similar native range, though perhaps a bit more widespread. It can usually be differentiated by the leaves shown here that clasp and nearly wrap all the way around the stem. However, they can hybridize, making identification difficult.

Lobelioideae Subfamily

Lobelia appendiculata—Pale Lobelia

This species is an annual unbranched herb that grows up to 60 cm tall with oblong to egg-shaped leaves that clasp partway around the stem. It has pale blue to white two-lipped flowers (2 upper lobes and 3 larger lower ones) in a loose terminal spike. It is native to the south-central USA.

Lobelia cardinalis—Cardinal Flower

This herbaceous perennial grows up to 1.2 m tall and is found mostly in or near bogs, riverbanks, swamps, or wet forests. It has large, lance-shaped to oval leaves with toothed margins. Flowers are large and bright red with 5 deeply cut lobes. Plants with pink or white flowers occasionally occur. It is native to southeastern Canada through the eastern and southern USA, south to northern Colombia.

Lobelia spicata—Pale Spike Lobelia

This short-lived perennial is often found flowering below taller grasses in sunny or semi-shaded prairies, woodlands, and disturbed areas. They have simple, variously elongated-shaped leaves with shallow teeth and are most known for their sometimes densely flowered spikes of white or pale blue flowers, like those in the photo. Native to southern Canada and the eastern USA.

Scientific Botanical Description of the Campanulaceae Family

Habit & Leaf Form of the Campanulaceae Family

Mostly perennial herbs with some annual or biennial and a few shrubs or small pachycaul trees with heights from 8 cm to over 2 m tall (excluding trees). They are laticiferous, which is an important identifying characteristic. Variously hydrophytic to xerophytic, and when hydrophytic, they are rooted with emergent and submerged leaves. Other plants may or may not have a basal aggregation of leaves. Leaves usually alternate or sometimes are opposite or whorled.

Leaves are petiolate or subsessile, sheathing or non-sheathing, and when sheathing, they have free margins. Leaves are not gland-dotted; they lack a pulvinus and stipules and are usually simple or sometimes compound–pinnate. Lamina, when simple, may be dissected or entire. When entire, it is linear, lanceolate, oblanceolate, oblong, ovate, obovate, or orbicular. When dissected, it is pinnatifid or palmatifid. Lamina margins are crenate, serrate, or dentate.

Flowers of the Campanulaceae Family

Plants are always hermaphrodites. Pollination is entomophilous and conspicuously specialized via modifications of the style with sterile tissue covering the stigmas. Flowers are solitary or aggregated in cymes, racemes, spikes, and umbels, sometimes pseudanthial. Inflorescences are scapiflorous or not, terminal or axillary, and with or without involucral bracts. Flowers are medium to large; regular to very irregular; 5-merous; tetracyclic. Perianth has a distinct calyx and corolla of 10 or 16–20 (Michauxia) parts in 2 whorls.

Calyx 5 or 8–10 (Michauxia); 1 whorled; free or connate (depending on interpretation, with the tube nearly always being united with the ovary); basally appendaged (e.g., Campanula with adjoining pairs of sepals contributing to each appendage); spurred or not; imbricate or valvate. An epicalyx is sometimes present. Corolla 5 or 8–10 (Michauxia); 1 whorled; connate (usually) or free (Jasione); valvate; often campanulate with long tubular bells or open starry ones; bilabiate or regular; mostly blue, but also white, yellow, red, pink, or purple; spurred (e.g., Heterotoma) or not spurred.

Androecium of the Campanulaceae Family

There are 5 or 8–10 (Michauxia) androecial members made of exclusively fertile stamens that are free of the perianth or adnate low down on the corolla and free of one another or coherent, 1-whorled, and sometimes forming a column around the style. Stamens are isomerous with the perianth, opposite the sepals, and alternating with the corolla members; they are filantherous or laminar and filantherous (e.g., being laminate below the filaments in Wahlenbergia). Filaments are sometimes basally appendiculate (sometimes in Campanula). Anthers are cohering and sometimes terminating an androecial column (e.g., Centropogon, Burmeistera) or separate, dehiscing via longitudinal slits, introrse, and tetrasporangiate.

Gynoecium of the Campanulaceae Family

The gynoecium is 2, 3, 5 (8 in Ostrowskia) or 8–10 carpelled (Michauxia). The pistil is 2 or 3 celled or occasionally 5 (6–10) celled. The gynoecium is synstylovarious and with a usually inferior ovary or rarely superior. The ovary is 2, 3, or 5 (6–10) locular. Styles 1. Stigmas equal in number to carpels; wet or dry type; papillate or non-papillate; Group II or IV type. Placentation axile with 10–50 ovules per locule; horizontal; non-arillate; anatropous; unitegmic; tenuinucellate.  

Fruit of the Campanulaceae Family

The fruit of the Campanulaceae is almost always a non-fleshy, dehiscent septicidal, loculicidal, valvular, or irregularly splitting capsule or, rarely, a fleshy indehiscent berry. Seeds are small, endospermic, oily, and rarely starchy and are sometimes winged. 

Taxonomy of Campanulaceae

There are 2,380 species in 84 genera of the Asterales order of the core Eudicots (dicots).

The family is divided into five subfamilies, 2 of which are very widespread:

1. Campanuloideae is a large subfamily characterized by polysymmetric flowers, stamens that sprawl at the bottom of the corolla tube after the anthers have dehisced, an inferior ovary, and long-hairy styles. These are widespread and found worldwide, with especially high diversity in the north temperate Old World.
2. Lobelioideae is a subfamily of herbs or small trees with terminal, occasionally axillary, inflorescences and large to small resupinate flowers. Stamen filaments are connate at least apically, and anthers are connate. They are mostly tropical, especially common in the New World with a major center of diversity in the Andes and over 100 endemic species found on the Hawaiian Islands. They are not present in the Arctic and are absent from the Near East and Central Asia.
3. Nemacladoideae is a small subfamily of tiny annuals (rarely perennial) with sub-opposite leaves, racemes without bracteoles, and small flowers that are not resupinate. Anthers are connivent; filaments are connate apically and may be free at the base. These are restricted to the southwestern USA (especially California) and northwestern Mexico.
4. Cyphioideae is a group of perennial herbs (twining vines) and shrubs with tuberous roots. The fused corolla is split almost to the base into two groups, usually with three upper lobes and two lower lobes. Stamen filaments may be free or connate. Mostly in Southern Africa but also in East Africa and the Cape Verde Islands.
5. Cyphocarpoideae is a small subfamily endemic to Chile and is made of annual or perennial spiny herbs with deeply lobed leaf margins and foliaceous bracts. The upper corolla lobe is sub-hooded, and the lower lobes show three ridges.

Genera of the Campanulaceae:

Campanuloideae: Adenophora (68), Asyneuma (37), Azorina (1? or syn. Campanula), Berenice (1), Campanula (452), Canarina (3), Codonopsis (49), Craterocapsa (5), Cryptocodon (1), Cyananthus (19), Cyclocodon (3), Cylindrocarpa (1), Echinocodon (1), Edraianthus (21), Favratia (1), Feeria (1), Githopsis (4), Gunillaea (2), Hanabusaya (1), Heterochaenia (4), Heterocodon (1), Himalacodon (1), Homocodon (2), Jasione (14), Kericodon (1), Legousia (6), Merciera (6), Michauxia (8), Microcodon (4), Muehlbergella (1), Musschia (3), Namacodon (1), Nesocodon (1), Ostrowskia (1), Pankycodon (1), Peracarpa (1), Petromarula (1), Physoplexis (1), Phyteuma (22), Platycodon (1), Prismatocarpus (27), Pseudocodon (8), Rhigiophyllum (1), Roella (22), Sachokiella (1? or syn. Campanula), Sergia (2), Siphocodon (2), Theilera (2), Theodorovia (1? or syn. Campanula), Trachelium (2), Treichelia (2), Triodanis (6), Wahlenbergia (263), Zeugandra (2).

Lobelioideae: Apetahia (? or syn. Sclerotheca), Brighamia (2), Burmeistera (129), Centropogon (212), Clermontia (23), Cyanea (81), Delissea (15), Dialypetalum (5), Diastatea (9), Dielsantha (1), Downingia (13), Grammatotheca (1), Heterotoma (1), Hippobroma (1), Howellia (1), Isotoma (10), Legenere (1), Lobelia (444), Lysipomia (32), Monopsis (15), Palmerella (1), Porterella (1), Ruthiella (4), Sclerotheca (10), Siphocampylus (237), Solenopsis (13), Trematolobelia (8), Unigenes (1), Wimmeranthus (1), Wimmerella (10).

Nemacladoideae: Nemacladus (26), Parishella (? syn. Nemacladus), Pseudonemacladus (1).

Cyphioideae: Cyphia (76).

Cyphocarpoideae: Cyphocarpus (4).

Key Differences From Similar Families

Campanulaceae is easy to distinguish by the combined presence of latex, simple leaves, and an inferior ovary. Sometimes plants from Acanthaceae, Lamiaceae, and Rubiaceae with long reddish or orange corolla tubes are placed in Campanulaceae, but they differ in leaves that are usually opposite and having free stamens and anthers.

Distribution of the Campanulaceae

The Campanulaceae are found from frigid zones to tropical climates with a cosmopolitan distribution excluding tropical Africa and Antarctica. Found from deserts to rainforests and the Arctic, but the majority of species are by far northern temperate species.

In the Americas, the Campanulaceae are found through Canada, including the Arctic (and Greenland), and south through the USA, Mexico, Central America, and South America.

Distribution of Campanulaceae in the Americas

NOTE: This data was gathered 4-5 years ago and may not reflect current genus names and status.

Canadian Campanulaceae Genera Include:

Campanuloideae: Campanula 19 spp., including 18 native in all of Canada, including the Arctic (and Greenland), and 1 sp. intro to BC; Githopsis 1 W NAM endemic sp. native to S Vancouver Island, BC; Heterocodon monospecific W NAM endemic native to BC; Jasione 1 sp. intro to BC?; Triodanis 1 sp. native to BC, ON, and QC. Lobelioideae: Downingia 2 spp. native to BC, AB, and SK; Isotoma 1 sp. intro to BC; Lobelia 2 spp. native to BC, ON, and QC, and ephemeral NB.

USA Campanulaceae Genera Include:

Campanuloideae: Asyneuma 1 sp. native to OR and CA; Campanula 34 spp., including 33 native to most of the USA and AK but excluding OK, AR, LA, MS, and 1 sp. intro to NV and NH; Clermontia 22-23 narrow endemic spp. of HI; Cyanea 80-81 spp. narrow endemic genera of HI; Githopsis 4 spp. W NAM endemic genera native MT, WA, OR, and CA (2 endemics); Heterocodon monospecific W NAM endemic native to WA, OR, CA, NV, ID, MT, WY, and CO; Jasione 1 sp. intro to WA, OR, NC, MD, PA, DE, NY, CT, NJ, RI, and MA; Legousia 1 sp. intro to CA and PA; Platycodon 1 sp. intro to NY, PA, NC, and HI; Triodanis 6 spp. native to all of the USA (5 endemics), and intro HI; Wahlenbergia 2 spp. intro to TX, LA, AR, MS, AL, GA, SC, NC, and FL. Lobelioideae: Brighamia 2 spp. narrow endemic genera of HI; Delissea 15 spp. narrow endemic genera of HI; Downingia 13 spp. native to WA, ID, MT, OR, WY, CA, NV, and UT, includes 9 USA endemics, mostly in CA; Hippobroma monospecific intro to FL and HI; Howellia monospecific W USA endemic of WA, ID, MT, OR, and CA; Legenere monospecific Americas disjunct endemic of CA + Patagonia; Lobelia 43 spp. native and intro to the entire USA and HI and native in AK; Palmerella monospecific narrow endemic of S CA + N BC Mexico; Porterella monospecific endemic of OR, ID, WY, CA, UT, and AZ; Trematolobelia 8 spp. narrow endemic genera of HI. Nemacladoideae: Nemacladus 18-26 W NAM endemic spp. native to OR, ID, CA, NV, UT, AZ, and NM, including many endemic to W USA.

Mexico Campanulaceae Genera Include:

Campanuloideae: Campanula 1-2 spp. native to NE Mexico and intro to SW+SE Mexico and Ver; Githopsis 1 W NAM endemic sp. native BC and Guadalupe Is.; Heterocodon monospecific W NAM endemic native to NW Mexico; Triodanis 1 sp. native throughout Mexico except the SE. Lobelioideae: Centropogon 4+ spp. mostly neoendemic, native to most of Mexico except the NW, and includes 1 endemic species; Diastatea 8 spp. including 7 endemics native to most of Mexico (exc. NW); Downingia 1 sp. native to NW Mexico; Heterotoma monospecific neoendemic native to NE+C+SW+NE Mexico; Hippobroma monospecific intro to all of Mexico; Lobelia ~86 spp., including ~20 endemic to all of Mexico; Palmerella monospecific narrow endemic of S CA + N BC Mexico; Wimmeranthus monospecific endemic of SW Mexico. Nemacladoideae: Nemacladus 10 W NAM endemic spp. native to NW Mexico, mostly in BC, including 1 endemic to BC; Pseudonemacladus monospecific endemic to NE Mexico.

Neotropical Campanulaceae Genera Include:

Campanuloideae: Triodanis 1 sp. native to Guatemala, Colombia, Ecuador, Peru, Bolivia, Paraguay, S+SE Brazil, Uruguay, and Argentina, and intro to Jamaica and Dominican Republic; Wahlenbergia 6 spp. neoendemics of E+S Brazil (inc. 1 Brazil endemic), Colombia, French Guiana, Peru, Ecuador, Bolivia, Paraguay, Argentina, C Chile, and Uruguay. Cyphocarpoideae: Cyphocarpus 3 spp. narrow endemic genera of N+C Chile. Lobelioideae: Burmeistera 129 spp. neoendemic genera of Guatemala, Honduras, Costa Rica, Panama, Colombia, Venezuela, Ecuador, and Peru; Centropogon ~211 spp. mostly neoendemic native to CAM (exc. Belize) and tropical SAM S to Peru, Bolivia, and C+SE Brazil, and the Lesser Antilles (2 endemics); Diastatea 2 spp. native to CAM (exc. Belize), Colombia, Venezuela, Ecuador, Peru, Bolivia, and NW Argentina; Heterotoma monospecific Mexico and neoendemic native to Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica; Hippobroma longiflora monospecific originally endemic Jamaica but widely introduced elsewhere; Lobelia ~50?? spp. native to CAM, the Antilles, all of SAM except Guyana and including Galapagos; Lysipomia 32 spp. Andes endemic genera of Venezuela, Colombia, Ecuador, Peru, and Bolivia; Siphocampylus 237 spp. neoendemic genera of Costa Rica, Panama, the Greater Antilles, Colombia, Venezuela, Ecuador, Peru, Bolivia, Brazil (exc. N), Paraguay, N Argentina, and Uruguay.

Patagonia Campanulaceae Genera Include:

Campanuloideae: Campanula 1 sp. intro to S Argentina and Falkland Is.; Triodanis 1 sp. native to S Argentina; Wahlenbergia 1 sp. native to S Chile. Lobelioideae: Downingia 1 sp. native throughout Patagonia (also native in California); Legenere monospecific Americas disjunct endemic of California + Patagonia; Lobelia 5+ spp. native throughout Patagonia and Falkland Is. and intro to South Georgia Is.

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, along with my own personal observations throughout North America.
• Canadensys: Acadia University, Université de Montréal Biodiversity Centre, University of Toronto Mississauga, University of British Columbia. http://data.canadensys.net/explorer (accessed 2020 – current)
• 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.
• FNA (1993+). Flora of North America. https://floranorthamerica.org/Main_Page. Accessed 2022-current.
• GBIF.org (2020+), GBIF Home Page. Available from: https://www.gbif.org
• iNaturalist.org (2020+). https://www.inaturalist.org/. Accessed 2020-current.
• 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+). 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 2020-present.
• WFO (2022): World Flora Online. Published on the Internet: http://www.worldfloraonline.org. Accessed Spring 2022 – current

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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].