STUDIES IN THE HELIANTHEA.E (ASTERACEAE) , VII. NOTES ON THE GENUS, MONACTIS Harold Robinson Department of Botany Smithsonian Institution, Washington, D.C. 20560, Efforts to identify members of the Heliantheae from Ecuador have shown a concentration of problems in the genus Monactis . Neither Monactis nor the segreg-ate genera Astemma Less, and Monopholis Blake have been reevaluated since their original description and treat-ments at the species level have been erratic. The present preliminary revision attempts to properly delimit the genus Monactis and provides necessary new species descriptions and new combinations. Concepts are summarized in two provisional keys to the Ecuador-ian and Peruvian species. The genus Monactis was originally described in Nova genera et species plantarum by Humboldt, Bonpland and Kunth in 1818 to include two species from the northern Andes. The characters emphasized were "involucrum oligophyllum, imbricatum, pauciflorum. Receptaculum paleaceum. Flosculi disci nonnulli, tubulosi, hermaphroditi; radii subsolitarius , ligulatus, femineus. Akenia calva." The name was derived from the single-rayed heads of the first species, M. flaverjoi -des HBK, resembling the condition found in members of the genus Flaveria . The species is sometimes cited as Ecuadorian but the type locality is given as near Jaen which is in Cajamarca, Peru. The second species of Monactis , M. dubia HBK of southern Elcuador was described as lacking rays and having reduced stamens. It was suggested that the species was dioecious and on the basis of this sugges-tion Lessing in 1832 removed the second species as a monotypic genus , Astemma . Fragments of the type in the U.S. National Herabrium show that the anthers are aborted but this is regarded as an indication of apomixis rather than a dioecious condition. Other features of the species agree with Monactis and the species is close to if not the same as M. Holwayae. Bentham and Hooker (1873) recognized both Astemma and Monactis , the former distinguished as dioecious and the later being placed in a group with inner phyllaries investing the ray achenes. Two species of Monactis were cited without providing names and the nature of the supposed second species 33
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