Genus of plants
Spermacoce or false buttonweed[2] is a genus of flowering plants in the family Rubiaceae. It comprises about 275 species found throughout the tropics and subtropics.[3] Its highest diversity is found in the Americas, followed by Africa, Australia and Asia.
Description
The species are herbs or small shrubs with small- to medium-sized, four-lobed flowers arranged in capitate inflorescences. Some have a brightly coloured calyx and are eye-catching, particularly the Australian species. The corolla is variable in colour, often white, but also all shades of blue, pink and maroon. The fruit is usually a two-seeded capsule, sometimes a schizocarp or nut.[4]
Selected species
Spermacoce is a highly diverse genus with about 275 species in many tropical and subtropical places around the globe.[3] North American species include:[5][6]
- Spermacoce alata Aubl. - West Indies, most of Latin America; naturalized in Africa, India, China, Southeast Asia, Australia, Melanesia
- Spermacoce assurgens Ruiz & Pav. - synonym of Spermacoce remota[3]
- Spermacoce brachysepala (Urb.) Alain in H.A.Liogier & L.F.Martorell - West Indian false buttonweed - Puerto Rico, Haiti, Dominican Republic
- Spermacoce capitata Ruiz & Pav. - baldhead false buttonweed - Central and South America from Belize to Argentina
- Spermacoce confusa Rendle - river false buttonweed - Florida, West Indies, Latin America from Mexico to Argentina
- Spermacoce densiflora (DC.) Alain - bouquet false buttonweed - Florida, West Indies, Latin America from Mexico to Argentina
- Spermacoce ernestii Fosberg & Powell - synonym of Spermacoce ovalifolia[3]
- Spermacoce eryngioides (Cham. & Schltdl.) Kuntze - whorled-leaf false buttonweed - West Indies including Puerto Rico; southeastern South America from Bolivia and Brazil to Argentina
- Spermacoce exilis (L.O. Williams) C. Adams - Pacific false buttonweed - Latin America from Mexico to Argentina, plus West Indies; naturalized in Africa, China, India, southeast Asia and some tropical oceanic islands
- Spermacoce floridana Urb. - synonym of Spermacoce keyensis [3]
- Spermacoce glabra Michx. - smooth false buttonweed - southern and eastern United States (mostly in the Lower Mississippi Valley); also South America
- Spermacoce keyensis Urb. - Florida false buttonweed - southern Florida, Bahamas, southern tip of Texas (Cameron County)
- Spermacoce latifolia Aubl. - synonym of Spermacoce alata[3]
- Spermacoce neoterminalis Govaerts - Everglades false buttonweed- southern Florida
- Spermacoce ovalifolia (M. Martens & Galeotti) Hemsl. - broadleaf false buttonweed - West Indies including Puerto Rico, Latin America from Mexico to Paraguay
- Spermacoce ocymoides Burm.f.
- Spermacoce prostrata Aubl. - prostrate false buttonweed - Florida, Mississippi, Alabama, West Indies including Puerto Rico; most of Latin America; naturalized in China, Vietnam, Sri Lanka and Java
- Spermacoce remota - Lam. - woodland false buttonweed - Florida, Georgia, Texas, Alabama, West Indies, much of Latin America; naturalized in Southeast Asia, China, India, New Guinea, Mauritius and many oceanic islands (including Hawaii)
- Spermacoce sintenisii (Urb.) Alain - synonym of Spermacoce brachysepala[3]
- Spermacoce tenuior L. - slender false buttonweed - Texas, Louisiana, Georgia, West Indies; Latin America from Mexico to Bolivia; naturalized in Tanzania, Java, Sulawesi and Galápagos
- Spermacoce terminalis (Small) Kartesz & Gandhi - synonym of Spermacoce neoterminalis[3]
- Spermacoce tetraquetra A. Rich. - pineland false buttonweed - Florida, West Indies, Mexico, Central America
- Spermacoce verticillata L. - shrubby false buttonweed - Florida, West Indies, most of Latin America; naturalized in Africa, Australia, assorted oceanic islands