A new concept of the genus Heterocoma is presented based on morphological and anatomical evidence. The genus is characterized by the combination of foliose subinvolucral bracts, fimbrillate or paleaceous receptacles, glabrous cypselae, and a caducous biseriate pappus (at least the inner series). A putative synapomorphy of the genus is the presence of phytomelanin in the cypselae walls. The monotypic genera Bishopalea, Sipolisia, and Xerxes are synonymized under Heterocoma with the following new combinations: Heterocoma ekmaniana, Heterocoma erecta, and Heterocoma lanuginosa. Two new species, Heterocoma gracilis and Heterocoma robinsoniana, are described and illustrated. The genus is endemic to the campos rupestres of the Brazilian Central Plateau. A key to the six species recognized in Heterocoma is provided.
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1 February 2013
Two New Species of Heterocoma (Asteraceae: Vernonieae) and a Broadened Concept of the Genus
Benoît Loeuille,
Jimi Naoki Nakajima,
Denise Maria Trombert Oliveira,
João Semir,
José Rubens Pirani
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Systematic Botany
Vol. 38 • No. 1
February 2013
Vol. 38 • No. 1
February 2013
Brazil
Compositae
phytomelanin
Sipolisiinae
taxonomy