''Cochliostema'' is a genus of plants with two species in the family

Commelinaceae Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with about 731 kn ...

(the spiderwort and dayflower family). The genus occurs from southern

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

to southern

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Systematics

''Cochliostema'' is a member of the subtribe Dichorisandrinae of the tribe Tradescantieae of the flowering plant family Commelinaceae. Its closest relative in the Dichorisandrinae is '' Plowmanianthus'', followed by '' Geogenanthus''. All three genera share the possession of flower petals fringed with moniliform trichomes. Within ''Cochliostema'' there are two species: '' Cochliostema velutinum'' R.W.Read and '' Cochliostema odoratissimum'' Lemaire. '' Cochliostema jacobianum'', a 19th-century name thought to represent another species and still popular among horticulturists, is considered as part of the latter species.

Morphology

Rosette Rosette is the French diminutive of ''rose''. It may refer to: Flower shaped designs * Rosette (award), a mark awarded by an organisation * Rosette (design), a small flower design *hence, various flower-shaped or rotational symmetric forms: ** R ...

, typically unbranched herbs with somewhat

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

, strap-shaped leaves. In the wild, plants grow as

epiphytes An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...

; however, terrestrial plants are found on or around tree falls suggesting that these ground-dwelling plants had been growing epiphytically. One species, ''Cochliostema odoratissimum'', is a tank-epiphyte, resembling certain bromeliads in this respect. This species also attains the greatest size for the genus, with its leaves reaching to 1 m in length, and plants sometimes reaching 2 m in height.

Flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are borne in large thyrses and are generally the largest (ca. 2.5 cm diam.), among the most fragrant, and arguably the most complex in the spiderwort family. They consist of 3

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s, 3 blue to blue-violet and fringed

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s, 3 stamens fused by their filaments in the upper half of the flower, and 3 carpels fused into a single trilocular

pistil Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

. The fused staminal structure has 3 spirally coiled

anther The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s enveloped and concealed by petaloid extensions of the filaments of the two lateral stamens contributing to the 3-staminate structure. These structures, termed "cuculli", are narrowed into two distal hose-like extensions.

References

*Hardy CR, DW Stevenson (2000) Development of the flower, gametophytes, and floral vasculature in ''Cochliostema odoratissimum'' (Commelinaceae). ''Botanical Journal of the Linnean Society'' 134 (1): 131–157. *Hardy CR (2001) Systematics of ''Cochliostema'', ''Geogenanthus'', and an undescribed genus in the spiderwort family, Commelinaceae. Ph.D. Dissertation, Cornell University, Ithaca, NY, USA. {{Taxonbar, from=Q5139392 Commelinaceae Commelinaceae genera Epiphytes Flora of Southern America Taxa described in 1859 Taxa named by Charles Antoine Lemaire