Stylotrichium, Mattfeld, 1923

Amorim, Vivian Oliveira & Roque, Nádia, 2017, Stylotrichium hortensiae (Asteraceae-Eupatorieae): A new species from Chapada Diamantina, Bahia, Brazil, Phytotaxa 308 (2), pp. 283-288 : 287

Key to the species of Stylotrichium

1. Cypselae epappose (pappus absent) ................................................................................................................................................ 2.

– Cypselae with pappus ...................................................................................................................................................................... 3.

2. Branches glanduliferous; laminae 1.2–1.8 × 0.7–1.2 cm, margins crenate, adaxial surface with glandular trichomes; paleae 1–2; corolla ca. 2.7 mm long, anther connective appendages obtuse; cypselae scabrous, densely sessile glandular trichomes, carpopodium annular, symmetrical, not decurrent into ribs ( Fig. 3F ) ............................................................................................... S. sucrei

– Branches scabrous to glabrescent; laminae 0.5–0.7 × 0.2–0.4 cm, margins entire, adaxial surface glabrous; paleae 4; corolla ca. 1.4 mm long, anther connective appendage emarginated; cypselae glabrous, rarely glabrescent, carpopodium terete, asymmetric, decurrent into ribs ( Fig. 3C ) ....................................................................................................................................... S. glomeratum

3. Laminae oblanceolate to oblong, 3.5–8 cm long; involucral bracts lanceolate; paleae 3–4; flowers 35–45, anther connective appendages as long as wide, style ca. 6.5 mm long; elements of the pappus 1–1.5 mm long ( Fig. 3D ) ........................... S. hortensiae

– Laminae obovate, orbicular or obtrullate, 0.4–3.3 cm long; involucral bracts oblong to oblanceolate; paleae 1–2; flowers 20–25; anther connective appendages wider than long, style 3.9–5 mm long; elements of the pappus 0.2–1 mm long ............................ 4.

4. Laminae broadly obovate to orbicular, 2.9 × 3.3 cm; cypselae 3-ribbed, pappus 0.2–0.6 mm long ( Fig. 3E ) ........ S. rotundifolium

– Laminae obovate to obtrulate, 0.4–1.5 × 0.2–1 cm; cypselae 5-ribbed, pappus 0.6–1 mm long .................................................... 5.

5. Leaves short petiolate (ca. 0.4 mm long), venation reticulodromous basal ( Fig. 3B ) .................................................... S. edmundoi

– Leaves sessile, venation reticulodromous suprabasal ( Fig. 3A ) ................................................................................ S. corymbosum

Figures

FIGURE 3. Species of Stylotrichium. A. Stylotrichium corymbosum. B. Stylotrichium edmundoi. C. Stylotrichium glomeratum. D. Stylotrichium hortensiae. E. Stylotrichium rotundifolium. F. Stylotrichium sucrei. Photos by V.O. Amorim (C, D, F) and A. Gandara (A, B, E).