Systematic revision of the genus Isostigma (Asteraceae, Coreopsideae).

PETER, GUADALUPE

CANDOLLEA

CONSERVATOIRE ET JARDIN BOTANIQUES VILLE GENEVE

Lugar: Ginebra; Año: 2009 vol. 64 p. 5 - 30

0373-2967

Isostigma Less. (Asteraceae, Coreopsideae) is a South American genus, distributed in Argentina, Brazil, Bolivia, Paraguay, and Uruguay. The genus includes 11 species of perennial herbs or subshrubs, with leaves entire, furcate, or pinnatisect, capitula generally radiate, involucres 3-4-seriate, ray florets female, disc florets perfect and 4-5-lobed, style with appendage branches, cypselae linear and flat, pappus generally 2-aristate. All the species have Kranz anatomy in both stems and leaves. A classification into two subgenera is proposed, 1)Subg. Isostigma: I. brasiliense (Gardner) Benth. & Hook.f., I. cordobense Cabrera, I. dissitifolium Baker, I. peucedanifolium (Spreng.) Less., I. simplicifolium Less., and I. sparsifolium Guad.Peter; and 2)Subg. Microtrichon Guad.Peter: I. acaule (Baker) Chodat, I. herzogii Hassl., I. hoffmannii Kuntze, I. molfinianum Sherff, and I. scorzonerifolium (Baker) Sherff. One subgenus and one variety are described, and three new status and combinations are made. Three lectotypes and two neotypes are designated. Distribution maps and keys to the South American genus of Coreopsideae and to all species of Isostigma are provided.