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



1. Apocynum suksdorfii Greene, Pittonia 5: 65. 1902. 



Apache County to Coconino and Yavapai Counties (apparently 

 also in the Santa Catalina Mountains, Pima County), 3,000 to 7,000 

 feet, May to August. Colorado to Washington, south to New Mexico 

 and Arizona. 



The var. angustifolium (Wooton) Woodson (A. angustifolium 

 Wooton), with lanceolate leaf blades not more than 2 cm. wide, is 

 more common in Arizona than the typical form which has oblong- 

 lanceolate blades, some of them commonly at least 2.5 cm. wide. 



A. jonesii Woodson, known only by the type collection at Flagstaff, Arizona 

 (M. E. Jones in 1884), is closely related to A. suksdorfii, differing chiefly in having 

 somewhat broader calyx lobes and a somewhat more urceolate corolla. 



2. Apocynum cannabinum L., Sp. PL 213. 1753. 



Collections in the White Mountains (Apache County), at Port 

 Whipple (Yavapai County) , and in the Huachuca Mountains (Cochise 

 County) are cited by Woodson, who refers them to var. glaberrimwn 

 A. DC, characterized by absence of pubescence. The species occurs 

 throughout the United States and in southern Canada. 



3. Apocynum sibiricum Jacq., Hort. Bot. Vind. 3: 37. 1770. 



Apocynum hypericifolium Ait., Hort. Kew. 1: 304. 1789. 



Willow Spring, southern Apache Coimty (Palmer 511), White Moun- 

 tains, Navajo County (Hough 109), Clemenceau, Yavapai Coimty 

 (W. W. Jones 79) , June to July. Throughout much of North America. 



The form occurring in Arizona is var. salignum (Greene) Fernald 

 (A. salignum Greene), which has a narrower corolla tube than in typi- 

 cal A. sibiricum. 



4. Apocynum androsaemifolium L., Sp. PI. ed. 2, 311. 1762. 



Apocynum ambigens Greene, PI. Baker. 3: 17. 1901. 



Apache County to Coconino County, south to Cochise and Pima 

 Counties, 7,000 to 8,800 feet, openings in pine forests, etc., June and 

 July. Canada southward to Georgia and Arizona. 



The most attractive of the species occurring in Arizona and also the 

 most widely distributed and abundant. Most of the Arizona speci- 

 mens belong to the presumably typical form, with leaves pubescent 

 beneath, but var. glabrum Macoun (A. ambigens Greene), with leaves 

 glabrous beneath, has been collected in the White Mountains, Apache 

 County (Goodding 1210), and at Flagstaff, Coconino County (Thornber 

 in 1930). 



5. Apocynum medium Greene, Pittonia 3: 229. 1897. 



Apocynum abditum Greene, Leaflets 2: 105. 1910. 



Coconino, Yavapai, Gila, and Cochise Counties, 5,000 to 7,000 feet, 

 May to August, type of A. abditum from the Coconino National 

 Forest (Pearson 235). Throughout much of North America. 



The typical form, with leaves pubescent beneath, is much more 

 common in Arizona than var. floribundum (Greene) Woodson (A.flori- 

 bundum Greene) with leaves entirely glabrous. The variety has been 

 collected at the Grand Canyon (Hitchcock in 1915) and near Prescott 

 (Sparks in 1902). 



