FLOWERING PLANTS AND FERNS OF ARIZONA 527 



The Arizona plants are best referred to var. mohavensis Ferguson. 

 The varieties of this species are ill defined and vague. 



6. Croton texensis (Klotzsch) Muell. Arg. in DC, Prodr. 15 2 : 692. 

 1866. 



Hendecandra texensis Klotzsch in Wiegmann, Arch. Naturgesch. 

 7: 252. 1841. 



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

 and Pima Counties, 1,200 to 7,000 feet, very common, roadsides, 

 fields, and dry stream beds. Illinois to Wyoming, south to Arkansas, 

 Arizona, and Mexico. 



This plant is sometimes called doveweed, the seeds being a 

 favorite food of that bird. The plant gives off a disagreeable odor, so 

 strong as to be noticeable to passing motorists. Hay containing this 

 plant is reported to have poisoned cattle. The Hopi Indians use it as 

 an emetic and an eyewash. 



4. DITAXIS 



Herbs or shrubs with mostly malpighiaceous hairs; leaves simple, 

 alternate, exstipulate; flowers mostly monoecious, borne in bracteate 

 axillary racemes, or sometimes solitary; calyx 5-lobed; petals 5 or 

 sometimes wanting in the pistillate flowers; glands 5, alternating with 

 the petals; stamens 8 to 12 (usually 10), the filaments united below 

 into a column (androphore), the anthers in 2 whorls, the lower with 

 5 or 6, the upper with 3, 5, or 6 anthers; ovary 3-celled, the ovules soli- 

 tary; styles 3, bifid, distinct or partially connate; seeds not caruncu- 

 late, small. 



Key to the species 



1. Gland-tipped teeth present on the leaves, bracts, and pistillate sepals. 



1. D. ADENOPHORA. 



1. Gland-tipped teeth lacking (2). 



2. Claws of the staminate petals entirely free from the column of united fila- 

 ments (androphore) ; stigmas not flattened, sometimes subclavate; leaves 

 petiolate (3). 

 3. Pistillate petals ovate-lanceolate, with a few short hairs on the back scarcely 

 extending beyond the tip of the petal, or the margin shortly ciliate; styles 

 united only at base ; glands in the staminate flowers mostly thickish, obtuse ; 

 seeds shallowly faveolate 6. D. neomexicana. 



3. Pistillate petals obovate-cuneate, with abundant coarse hairs on the back 



extending markedly beyond the tip of the petal; styles united one-third to 

 one-half of their length; glands in the staminate flowers thin, acute; seeds 



nearly smooth 7. D. serrata. 



2. Claws of the staminate petals united to the androphore; stigmas flattened 

 and dilated (4). 



4. Leaves sessile; anther w r horls so close together as to be scarcely distin- 



guishable; seeds ellipsoid to subspheroid, 3.4 to 4.6 mm. long (5). 

 5. Pistillate petals wanting; sepals strigose outside; glands linear. 



2. D. MERCURIALINA. 



5. Pistillate petals present; sepals glabrous outside; glands not longer than 



wide 3. D. cyanophylla. 



4. Leaves petiolate; anther whorls obviously distinct; seeds definitely truncate 

 at base (6) . 



6. Little-branched shrub 1 to 1.9 m. high; lateral branches more than 3 mm. 



thick except at tip, pithy; seeds trigonous-pyramidal, truncate, -4 

 mm. or more long; leaves with few hairs or none. -4. D. brandegei. 

 6. Freely branching low shrub up to 0.75 m. high; main stem rarely more 

 than 3 mm. thick; seeds ovoid-truncate, 2.3 to 2.8 mm. long; leaves 

 thickl; 



286744°-42 34 



