Contributor

D.J. Nicholas Hind

Address

Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK

Description

Perennial herbs, rarely annual or biennial, rarely small shrubs, usually stem and/or leaf succulents. Leaves opposite or alternate, rarely verticillate, exstipulate, usually simple, usually glabrous, often glaucous, rarely with glands in leaf surface, sometimes pubescent, hairs either unicellular or multicellular and glandular-capitate or eglandular, margins usually entire, sometimes serrate, crenate or dentate, rarely coarsely lobed. Flowers usually in terminal cymose inflorescences, less often in spikes or racemes or solitary in leaf-axils, with or without bracts, regular, hermaphrodite, rarely unisexual and dioecious, mostly (3–)4–5 (–± 30)-merous; sepals 4–5 (–6), free or united into tube, persistent; petals same number as sepals, free or variously connate; stamens hypogynous or epipetalous, as many as petals or twice as many, in one whorl (Crassula-lineage) or more usually two whorls (Sedum-lineage), frequently obdiplostemenous, with outer whorl alternate and free from petals and inner whorl adnate to petals; filaments free or adnate to petals; anthers dorsifixed, bithecous, introrse, opening by a longitudinal slit; nectaries scale-like and usually present between the stamens and carpels. Carpels superior, equal in number to petals, free or slightly connate at base, unilocular; ovules (few–) many, inserted on adaxial suture, submarginal or proximally axile; styles short or elongated, stigmatic surface on inner side of apex. Fruit usually of separate follicles, rarely fruit a capsule, follicles membranous or leathery, often surrounded by persistent membranous corolla, opening on adaxial side. Seed minute, glabrous, testa variously striate and sometimes ornamented with ridges or papillae; endosperm usually present and sparse; embryo straight.

Notable genera and distinguishing features

Largest genus is Sedum with c. 500 spp. max.; Echeveria is the largest in the Western hemisphere with c. 150 spp., followed by Sedum with c. 110 spp., Crassula (c. 11 spp. in the Neotropics) and Villadia with c. 10 in Peru.

General notes

Main areas of speciation include Africa (dry areas), Madagascar, Macaronesia and Mexico.

Up to six subfamilies are recognized but following DNA analysis only two main lineages are seen clearly – the Crassula-lineage and the Sedum -lineage.

Mostly plants of dry, rocky habitats, usually terrestrial but rarely epiphytic and very rarely aquatic.

Top

Important literature

Bywater, M. & G. E .Wickens. (1984). New World species of the genus Crassula. Kew Bull. 39(4): 699–728.
Claussen, R. T. (1959). Sedum of North America north of the Mexican Plateau. An exposition of taxonomic methods. Comstock Publishing Associates, Ithaca, New York. pp. 380.
Fröderström, H. (1936). The genus Sedum L. : a systematic essay. Part. IV. Acta Horti Gotoburgensis. 10, Appendix. 1–181 + pl. I–CXV.
Walther, E. (1972). Echeveria. California Academy of Sciences, San Francisco. pp. 426.

Crassulaceae
Family index \| Glossary
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Contributor Address Description Notable genera and distinguishing features General notes Important literature	Contributor D.J. Nicholas Hind Address Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK Description Perennial herbs, rarely annual or biennial, rarely small shrubs, usually stem and/or leaf succulents. Leaves opposite or alternate, rarely verticillate, exstipulate, usually simple, usually glabrous, often glaucous, rarely with glands in leaf surface, sometimes pubescent, hairs either unicellular or multicellular and glandular-capitate or eglandular, margins usually entire, sometimes serrate, crenate or dentate, rarely coarsely lobed. Flowers usually in terminal cymose inflorescences, less often in spikes or racemes or solitary in leaf-axils, with or without bracts, regular, hermaphrodite, rarely unisexual and dioecious, mostly (3–)4–5 (–± 30)-merous; sepals 4–5 (–6), free or united into tube, persistent; petals same number as sepals, free or variously connate; stamens hypogynous or epipetalous, as many as petals or twice as many, in one whorl (Crassula-lineage) or more usually two whorls (Sedum-lineage), frequently obdiplostemenous, with outer whorl alternate and free from petals and inner whorl adnate to petals; filaments free or adnate to petals; anthers dorsifixed, bithecous, introrse, opening by a longitudinal slit; nectaries scale-like and usually present between the stamens and carpels. Carpels superior, equal in number to petals, free or slightly connate at base, unilocular; ovules (few–) many, inserted on adaxial suture, submarginal or proximally axile; styles short or elongated, stigmatic surface on inner side of apex. Fruit usually of separate follicles, rarely fruit a capsule, follicles membranous or leathery, often surrounded by persistent membranous corolla, opening on adaxial side. Seed minute, glabrous, testa variously striate and sometimes ornamented with ridges or papillae; endosperm usually present and sparse; embryo straight. Notable genera and distinguishing features Largest genus is Sedum with c. 500 spp. max.; Echeveria is the largest in the Western hemisphere with c. 150 spp., followed by Sedum with c. 110 spp., Crassula (c. 11 spp. in the Neotropics) and Villadia with c. 10 in Peru. General notes Main areas of speciation include Africa (dry areas), Madagascar, Macaronesia and Mexico. Up to six subfamilies are recognized but following DNA analysis only two main lineages are seen clearly – the Crassula-lineage and the Sedum -lineage. Mostly plants of dry, rocky habitats, usually terrestrial but rarely epiphytic and very rarely aquatic. Top Important literature Bywater, M. & G. E .Wickens. (1984). New World species of the genus Crassula. Kew Bull. 39(4): 699–728. Claussen, R. T. (1959). Sedum of North America north of the Mexican Plateau. An exposition of taxonomic methods. Comstock Publishing Associates, Ithaca, New York. pp. 380. Fröderström, H. (1936). The genus Sedum L. : a systematic essay. Part. IV. Acta Horti Gotoburgensis. 10, Appendix. 1–181 + pl. I–CXV. Walther, E. (1972). Echeveria. California Academy of Sciences, San Francisco. pp. 426.
Copyright Neotropikey: Royal Botanic Gardens, Kew