FLOWERING PLANTS AND FERNS OF ARIZONA 197 



5. Leaves with filiferous margins, rarely less than 20 mm. wide, never very 



rigid; stems sparingly branched above ground or simple (6). 



6. Inflorescence usually tomentose; leaves bluish green, thin and flexible, 



20 to 65 cm. long, the margins tardily filiferous, the marginal fibers 



straight and very fine; stems erect or ascending, 1 to 5.5 meters long; 



pistil 2 to 2.5 cm. long 6. Y. schottii. 



6. Inflorescence glabrous or exceptionally puberulent; leaves soon freely 



filiferous (7). 



7. Flowers 2.5 to 5 cm. long: pistil 2 to 3.25 cm. long: stems erect, 1 to 4.5 



meters high; leaves yellow green, 30 to 60 or even 150 cm. long, the 



marginal fibers very coarse, strongly curled. _ 7. Y. mohavensis. 



7. Flowers 6 to 8 or even i0 cm. long; pistils 4.5 to 8 cm. long (8). 



8. Plant acaulescent or with procumbent stems not more than 1 meter 

 long: inflorescence barely exceeding or included within the foliage; 

 peduncle 10 to 15 cm. long; leaves usually pale grayish green, 

 more or less rough to the touch, 50 to 75 cm. long, rigid except 

 at base, commonly more or less twisted, the marginal fibers 



usually coarse, strongly curle.d 8. Y. baccata. 



8. Plant with erect or strongly ascending stems, these often as many as 

 25 and up to 2.5 meters long: inflorescence well exserted; leaves 

 essentially smooth, dark yellowish green, the marginal fibers 

 moderately coarse 9. Y. arizoxica 



1. Yucca whipplei Ton., U. S. and Mex. Bound. Bot. 222. 1859. 



Hesperoyucca whipplei Baker, Kew Roy. Bot. Gard. Bui. Misc- 

 Inform. 1892: 8. 1892. 



Reported by McKelvey from Diamond Creek, a tributary of the 

 Colorado River (Mohave County). Western Arizona, southern Cali- 

 fornia, and Baja California, May and June. 



Our-Lord's-candle, Spanish-bayonet, Spanish-dagger. 



2. Yucca baileyi Woot. and Standi., Contrib. U. S. Xatl. Herbarium 



16: 114. 1913. 



Apache, Navajo, and Coconino Counties, 4,500 to 7,500 feet, sandy 

 plains, hillsides, and pine forests, May to June. Northwestern New 

 Mexico and Arizona. 



The raceme is always unbranched and short, sometimes not ex- 

 ceeding the foliage. 



Hopi Indians utilize the fibers for basket material. The flowers are 

 browsed by livestock, as also are the young leaves when other forage 

 is scarce. 



An unnamed variety with exceptionally short and rather coarsely 

 filiferous leaves, occasional in northern Arizona, is represented by a 

 collection from the Gorge of the Little Colorado River, 5,500 feet 

 {Kearney and Peebles 12819). 



3. Yucca angustissima Engelm. ex Trel., Mo. Bot. Gard. Ann. Rpt. 



13: 58. 1902. 



Coconino, Mohave, and Yavapai Counties, 2,700 to 7,500 feet, 

 May to June. Southern Utah and Nevada, northwestern New 

 Mexico, and Arizona. 



The typical form, found in Coconino and Yavapai Counties, has 

 leaves 4 to 7 mm. in width and often develops short lateral branches 

 toward the base of the inflorescence. A form with leaves 12 to 14 

 mm. wide has been observed at several localities in northern Mohave 

 County. 



