FLOWERING PLANTS AND FERXS OF ARIZONA 705 



Key to the species 



1. Stems rarely more than 15 cm. long, spreading or decumbent; upper leaves only 



slightly reduced; flowers mostly solitary; peduncles or pedicels much 



shorter than the subtending leaves, often decurved in fruit (2). 



2. Sepals linear or narrowly lanceolate; corolla rotate-campanulate, lavender 



drying violet purple; leaves appressed or narrowly ascending, closely 



imbricate along the stem, at least above, densely villous-sericeous on 



both faces 1. E. pilosus. 



2. Sepals lanceolate or ovate-lanceolate; corolla rotate, cream-colored or azure 



blue; leaves spreading, not closely imbricate along the stem, commonly 



glabrous above 2. E. sericeus. 



1. Stems commonly 30 cm. long or longer, erect or ascending; upper leaves greatly 

 reduced; flowers one or few on very slender, bracted peduncles longer 

 than the subtending leaves, the inflorescence a very open, leafy, terminal 

 panicle; corolla rotate, azure blue or occasionally white (3). 



3. Corolla not more than 7 mm. in diameter 3. E. alsinoides. 



3. Corolla 8 to 20 mm. in diameter 4. E. arizonicus. 



1. Evolvulus pilosus Nutt., Gen. PL 1: 174. 1818. 



Apache County to Coconino County, south to Cochise, Santa 

 Cruz, and Pima Counties, 3,000 to 5,500 feet, March to July. North 

 Dakota and Montana to Texas and Arizona. 



2. Evolvulus sericeus Swartz, Prodr. Veg. Ind. Occ. 55. 1788. 



Erol ndus wilcoxianus House, Torrey Bot. Club Bui. 33: 315. 

 1906. 



Navajo and Yavapai Counties to Cochise, Santa Cruz, and Pinal 

 Counties, 3,500 to 5,500 feet, May to September, type of E. wilcoxianus 

 from Fort Huachuca {Wilcox 96). Texas to southeastern California, 

 south to Argentina; West Indies. 



The common form in Arizona is var. discolor (Benth.) Gray (E. 

 discolor Benth., E. wilcoxianus House) . This has the upper leaf surface 

 green and glabrate, and the corolla usually cream-colored. The form 

 with leaves sericeous on both faces is occasional in Cochise County. 



3. Evolvulus alsinoides L., Sp. PL ed. 2, 392. 1762. 



Eastern Maricopa, Cochise, Santa Cruz, and Pima Counties, 2,500 

 to 5,000 feet, April to September. Widely distributed in tropical and 

 subtropical regions of both the Eastern and the Western Hemisphere. 



The Arizona form is var. acapulcensis (Willd.) Van Ooststroom (E. 

 acapulcensis Willd.) , which intergrades in Arizona with E. arizonicus, 

 differing chiefly in its smaller corolla. 



4. Evolvulus arizonicus A. Gray, Syn. Fl. ed. 2, 2f: 218. 1886. 

 Graham County to Yavapai County, south to Cochise, Santa Cruz, 



and Pima Counties, 3,500 to 5,000 feet, April to October, type from 

 Sonora near the border of Arizona. Southwestern New Mexico, 

 Arizona, and northern Mexico ; Argentina . 



One of Arizona's most beautiful wild flowers, with flowers a deep 

 sky blue. The typical form has the hairs of the herbage all or nearly 

 all short and appressed. Almost equally abundant, in the 3 southern 

 counties, is var. laetus (Gray) Van Ooststroom (E. laetus A. Gray) 

 with many of the hairs long and spreading. There is complete inter- 

 gradation of the 2 forms. The type of E. laetus was collected in the 

 Santa Rita Mountains (Pringle in 1881). 



