HAPLOPAPPUS ENORMIDENS (COMPOSITAE) , A NEW SPECIES FROM BAJA CALIFORNIA, MEXICO Reid Moran Natural History Museum, San Diego, California 92112 In June 1975 I found sterile plants of an unknown Haplo-pappus in the southwestern foothills of the Sierra San Pedro Mcfrtir, Baja California. In habit this plant resembled H. verni -cosus Brandegee, for which I mistook it from a distance; but the leaves were more like those of H. odontolepis Moran. I returned to the spot with Jack Reveal on July 19 and 20, to find the, plant in late flower and early fruit. It proves to be a new species somewhat intermediate between H^. vernicosus and H_. odontolepis . The new species is placed in Haplopappus section Hazardia as treated by Hall (1928). Clark (1975) compared Hazardia with Isocoma and Ericameria , also treated by Hall as sections of Hap -lopappus , and concluded that " Hazardia should be considered a distinct genus separate from Hall's other North American sections of Haplopappus ". With his evidence, he may judge that Hazardia should be in a different genus from Isocoma and Ericameria , even though not all taxonomists will necessarily agree. From the evi-dence given, however, he cannot logically conclude that Hazardia should be considered a distinct genus, for he made no comparisons with the South American type species and typical section of Hap-lopappus . Haplopappus odontolepis was described (Moran 1969) from flowering material, with no mature achenes. Although it seemed probable that the disk florets were fertile, a later collection shows them sterile. I am grateful to Dr. Ray Jackson for making chromosome counts of several collections of Haplopappus species and for re-viewing this manuscript. Haplopappus enormidens Moran, species nova. Fruticulus hispidulus resinosus 1-3 dm altus. Folia ses-silia elliptica acuta irregularissime spinoso-dentata plerumque 6-10 mm longa et 2-3 mm lata. Capitula solitaria vel pauca cy-mosaque, involucro cylindrico 9-12 mm longo et 2-3 mm lato, bracteis 16-21 squarrosis. Flores radii 3-6 fertiles, ligulis 3-4 mm longis. Flores disci 5-11 steriles. Achenia obcompressa cuneata 3-4 mm longa, pappo 4-6 mm longo. Typus: Moran et Reveal 22602 (SD 91522). Species H. odontolepidi similis, sed foliis capitulisque minoribus, bracteis uninervibus, et floribus paucioribus minoribusque. 371
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