Monographs Details: Dimerostemma brasilianum Cass.
Authority: Moraes, M. D. & Semir, J. 2009. A revision of Brazilian (Asteraceae, Heliantheae, Ecliptinae), with a new species and taxonomic adjustments. Brittonia. 61 (4): 341-365.
Description:Species Description - Basally woody perennial herbs or subshrubs 0.5-1 m tall, caespitose from a xylopodium. Leaves opposite throughout or sometimes alternate distally on the peduncles; petioles up to 7 mm long; blades 3-5*2.2- 5.5 cm, subchartaceous, broadly ovate to orbicular, rounded to truncate to subcordate at the base, rounded to obtuse at the apex, margins crenate-serrulate or sometimes serru- late, adaxial surface subtomentose or sometimes pilose-strigillose, mostly soft to the touch, the abaxial surface tomentose, grayish 3 -nerved from near to well above the base, mostly reticulate. Peduncles mostly slender or somewhat stout; heads subglobose; Outer phyllaries 7-13x5-10 mm, broadly ovate to elliptic; inner phyllaries 6-10x3-5 mm, elliptic, constricted at the base to obovate. Paleae 9-llxca. 2 mm when folded, with triangular to subulate tip 1-1.5 mm long. Ray florets absent or heads with a few small rays in transition to a tubulate shape, less than 10 mm long, rarely with deeply cleft linear laminas. Disc florets with corollas 4.5-6 mm long, lobes with a few trichomes abaxially. Cypselae 3.5-4.5x1.2-2 mm, slightly flat- tened, smooth or rarely sparsely and finely ruberculate, wings 0.5-1.2 mm wide, ciliate on the margin opposite the palea; pappus with awns 3-5.5 mm long, of the same length, longer or not less than % of the cypsela body, very broad and sometimes decurrent at base, crown up to 1.5 mm high, mostly laterally parted with squamelloid processes between the awns.
- Relatively abundant in Minas Gerais and Goiás, apparently local in Distrito Federal, Mato Grosso do Sul and São Paulo. It occurs in cerrado, campo and campo rupestre, between the coordinates 14°-21°S and 43°-50°W, at 900-1700 m. Flowering January to April.
Morphological comparisons have revealed that Dimerostemma rotundifolium is synony- mous with D. brasilianum. The placement of D. lippioides under the synonymy of D. brasilianum by Robinson (1984b) is not accepted here. Dimerostemma brasilianum differs from D. lippioides in the blades mostly subtomentose, soft to the touch, 3 -nerved from near to well above the base (Fig. 1C) vs. hispidulous, mostly asperous to the touch, always 3-nerved from the base (Fig. IB); peduncles mostly slender vs. stout, mostly elongated and leafless; involucres subglobose (Fig. 2C) vs. broadly campanulate (Fig. 2B); ray florets mostly absent or in transition to tubulate vs. well developed laminas; cypselae with much longer awns and a crown with squamelloid processes between the awns (Fig. 31) vs. without or sometimes with lateral squamelloid processes (Fig. 3J).