976 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



Key to the species 



1. Heads radiate, the rays white, conspicuous 1. H. radiatus. 



1. Heads discoid (2). 



2. Leaves entire and oblanceolate or obovate, or once pinnatifid with compara- 

 tively broad segments, these 2 to 6 mm. wide 2. H. mexicantjs. 



2. Leaves once to thrice pinnatifid, with narrowly linear or linear-filiform seg- 

 ments (3). 

 3. Plant biennial, single-stemmed, tall, 30 to 80 cm. high, leafy-stemmed, 

 the stem leaves numerous, at least the lower ones not conspicuously 

 smaller than the basal leaves; corolla teeth more than half as long as 



the throat 3. H. robustus. 



3. Plants perennial, usually several-stemmed, lower, rarely more than 30 cm. 

 high; corolla teeth one-third to one-fourth as long as the throat (4). 

 4. Plant scapose or subscapose, rarely with 2 or 3 stem leaves. 



4. H. LUGENS. 



4. Plant leafy-stemmed 5. H. pauciflorus. 



1. Hymenopappus radiatus Rose, Contrib. U. S. Natl. Herbarium 1: 



122. 1891. 

 Southern Apache, Navajo, and Coconino Counties, 5,000 to 7,000 

 feet, pine forests and open flats, May to July, type from Willow Spring, 

 Apache County {Palmer 615 in 1890). New Mexico and Arizona. 



2. Hymenopappus mexicanus A. Gray, Amer. Acad. Arts and Sci. 



Proc. 19: 29. 1883. 



Hymenopappus integer Greene, Pittonia 3: 249. 1897. 

 Hymenopappus obtustfolius Heller, Torrey Bot. Club Bui. 26: 



551. 1899. 

 Hymenopappus petaloideus Rydb., North Amer. Fl. 34: 54. 



1914. 



White Mountains (Apache and Navajo Counties), San Francisco 

 Peaks (Coconino County), south to the mountains of Cochise and 

 Pima Counties, 5,000 to 10,000 feet, open coniferous forests, common, 

 June to September, type of H. obtusijolius from Fort Valley, near 

 Flagstaff (MacDougal 240), type of H. petaloideus from the Chiricahua 

 Mountains (Blumer 1202). Western Texas to Arizona and Mexico. 



3. Hymenopappus robustus Greene, Torrey Bot. Club Bui. 9: 63. 



1882. 



Apache, Navajo, Coconino, Graham, and Gila Counties, 3,500 to 

 6,500 feet, mesas and slopes, April to September. Texas to central 

 Arizona and northern Mexico. 



4. Hymenopappus lugens Greene, Pittonia 4: 43. April 1899. 



Hymenopappus gloriosus Heller, Torrev Bot. Club Bui. 26: 



551. October 1899. 

 Hymenopappus scaposus Rydb., Torrev Bot. Club Bui. 27: 634. 



1900. 

 Hymenopappus macroglottis Rydb., ibid. p. 636. 



Apache County to eastern Mohave County, south to Santa Cruz 

 County, 5,000 to 7,000 feet, dry rocky slopes and mesas, usually with 

 pines or junipers, common, May to September, type of H. gloriosus 

 from Mormon Mountain, Coconino County (MacDougal 71), type of 

 H. scaposus from near Flagstaff (MacDougal 129), type of H. macro- 

 glottis from Oak Creek (Rusby in 1883). Colorado to Nevada, Ari- 

 zona, and southern California. 



