Most current classifications include the segregate family Lobeliaceae in Campanulaceae as subfamilyLobelioideae. A third subfamily, Cyphioideae, includes the genusCyphia, and sometimes also the generaCyphocarpus,Nemacladus,Parishella andPseudonemacladus. Alternatively, the last three genera are placed in Nemacladoideae, whileCyphocarpus is placed in its own subfamily, Cyphocarpoideae.
This family is almostcosmopolitan, occurring on all continents exceptAntarctica. In addition, species of the family are native to many remote oceanic islands and archipelagos.Hawaii is particularly rich, with well over 100 endemic species ofHawaiian lobelioids. Continental areas with high diversity are South Africa, California and the northernAndes.
Habitats range from extreme deserts to rainforests and lakes, from the tropics to the highArctic (Campanula uniflora), and from sea cliffs to high alpine habitats.
Although most Campanulaceae areperennial herbs (sometimes climbing, as inCodonopsis), there is also a large number ofannuals e.g. species ofLegousia.Isotoma hypocrateriformis is asucculent annual from Australia's dry interior. There are alsobiennials, e.g. the commonly cultivated ornamentalCampanula medium (Canterbury bells). Many perennial campanuloids grow in rock-crevices, such asMusschia aurea (Madeira) andPetromarula pinnata (Crete). Some lobelioids also grow on rocks, e.g. the peculiar perennial stem succulentBrighamia rockii inHawaii. Insular and tropical montane species in particular are often more or less woody and may bear the leaves in a dense rosette. When, in addition, the plant is unbranched, the result may be a palm- or treefern-like habit, as in species of the Hawaiian genusCyanea, which comprises the tallest of Campanulaceae,C. leptostegia (up to 14 m).Lysipomia are minute cushion plants of the highAndes, while giant rosette-forming lobelias (e.g.,Lobelia deckenii) are a characteristic component of the vegetation in the alpine zone on the tropical African volcanoes. In the HimalayaCampanula modesta andCyananthus microphyllus reach even higher, probably setting the altitudinal record for the family at 4800 m. Several species are associated with freshwater, such asLobelia dortmanna, anisoetid common inoligotrophic lakes in theboreal zone of North America and Europe, andHowellia aquatilis, anelodeid growing in ponds in SW North America.
There is usually abundant, white latex, but occasionally the exudate is clear and/or very sparse, as inJasione.
Leaves are oftenalternate, more rarely opposite (e. g.Codonopsis) or whorled (Ostrowskia). They are simple (Petromarula one of very few exceptions) entire (repeatedly divided in spp. ofCyanea), but often with dentate margin.Stipules are absent.
Inflorescences are quite diverse, including bothcymose andracemose types. InJasione they are strongly condensed and resembleasteraceouscapitula. In a few species, e. g.Cyananthus lobatus, flowers are solitary.
Flowers arebisexual (dioecious inDialypetalum) andprotandrous. Petals are fused into a corolla with 3 to 8 lobes. It may be bell- or star-shaped in subfamily Campanuloideae, while tubular and bilaterally symmetric in most Lobelioideae. Blue of various shades is the most common petal colour, but purple, red, pink, orange, yellow, white, and green also occur. The corolla may be down to 1 mm wide and long in some species ofWahlenbergia. At the other extreme, it reaches a width of 15 cm inOstrowskia.
Stamens are equal in number to, and alternating with the petals. Anthers may be fused into a tube, as in all species ofLobelioideae and some Campanuloideae (e.g.Symphyandra)
Carpel number is usually 2, 3 or 5 (8 inOstrowskia), and corresponds to the number of stigmatic lobes.
The style is in various ways involved in the "presentation" of the pollen, as in several other families of the order Asterales. InLobelioideae, pollen is, already in the bud stage, released into the tube formed by theanthers. During flowering, it is pushed up by the elongating style and "presented" to visiting pollinators at the apex of the tube, a mechanism described as a pollen pump. The style eventually protrudes through the anther tube, and becomes receptive to pollen. In Campanuloideae, the pollen is instead packed between hairs on the style, gradually being released as the hairs invaginate. Subsequently, the stigmatic lobes unfold, and become receptive.
Bees and birds (particularly hummingbirds andhawaiian honeycreepers) are probably the most common pollinators of Campanulaceae. A few confirmed and many probable cases of bat-pollination are known, particularly in the genusBurmeistera.Brighamia andHippobroma have pale or white flowers with a long-tubed corolla, and are pollinated byhawkmoths. Pollination by lizards has been reported forMusschia aurea andNesocodon mauritianus.
The ovary is usually inferior or, in some species, semi-inferior. Very rarely is it completely superior (e.g.Cyananthus). InCampanumoea javanica, calyx and corolla diverge from the ovary at different levels.
Berries are a common fruit-type in Lobelioideae (Burmeistera,Clermontia,Centropogon,Cyanea etc.), whilst rare in Campanuloideae (Canarina being one of few examples). Capsules, with very varying modes of dehiscence, are otherwise the predominating fruit type in the family.
Members of subfamily Lobelioideae contain the alkaloidlobeline. The principal storage carbohydrate of Campanulaceae isinulin, afructan also occurring in the relatedAsteraceae.
Eddie, W. M. M.; Shulkina, T.; Gaskin, J.; Haberle, R. C.; Jansen, R. K. (2003). "Phylogeny of Campanulaceae s. str. inferred from ITS sequences of nuclear ribosomal DNA".Annals of the Missouri Botanical Garden.90 (4):554–575.doi:10.2307/3298542.JSTOR3298542.
^Angiosperm Phylogeny Group (2009), "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III",Botanical Journal of the Linnean Society,161 (2):105–121,doi:10.1111/j.1095-8339.2009.00996.x,hdl:10654/18083
^Stevens, P.F. (2001 onwards)."Campanulaceae".Angiosperm Phylogeny Website. Retrieved 2022-04-23.
^Friis, Else Marie; Crane, Peter R.; Pedersen, Kaj Raunsgaard (August 2011).Early Flowers and Angiosperm Evolution. Cambridge University Press.ISBN9780521592833.
