FLOWERING PLANTS AND FERNS OF ARIZONA 563 



1. ABUTILON. Indian -mallow 



Plants herbaceous, suffrutescent or shrubby, canescent or tomen- 

 tose with short stellate hairs, or hirsute with longer simple hairs ; leaf 

 blades crenate or dentate, not or obscurely lobed; flowers solitary in 

 the axils, or in leafy panicles; corolla usually orange or yellow; fruit 

 truncate-cylindric or nearly globose, the carpels with smooth sides, 

 dehiscent nearly to the base when mature; ovules 2 or more in each 



carpel. 



Key to the species 



1. Carpels conspicuously inflated, muticous, with thin membranaceous walls, 



hispid with rather long simple hairs; fruit globose 1. A. crispum. 



1. Carpels not conspicuously inflated, with chartaceous or coriaceous walls, not 

 hispid or, if so, then mucronate to aristate; fruit not globose (2). 

 2. Plant annual, tall; carpels usually more than 10, with long, divergent 



awns 2. A. theophrasti. 



2. Plant perennial; carpels seldom more than 10 (3). 

 3. Carpels seldom more than 5 (4). 



4. Pubescence of the leaves sparsely strigose or substrigose, the hairs long, 

 rather stiff, mostly simple; stems glabrate or hirsute with very 

 long, simple, spreading or reflexed hairs; carpels aristate, the awns 



2 to 3 mm. long, hispid 3. A. thurberi. 



4. Pubescence fine or minute, the hairs mostly stellate; carpels muticous to 



short-cuspidate (5). 



5. Stems woody well above the caudex; herbage finely and densely 



puberulent; leaf blades considerably longer than wide, gradually 



acuminate; petals white or pink, with a dark crimson spot at 



base 4. A. pringlei. 



5. Stems not woody above the caudex or only near the base; pubescence 



coarser or more sparse; leaf blades little if any longer than wide, 



abruptly acuminate; petals not spotted (6). 



6. Leaf blades thickish, usually densely soft-canescent or tomentulose 



on both faces, the larger ones usually 4 cm. long or longer; 



flowers usually numerous, in leafy panicles; petals orange 



yellow, 6 to 10 mm. long; carpels muticous or nearly so. 



5. A. INCANUM. 



6. Leaf blades thin, less pubescent, dark green above, the larger ones 



about 3 cm. long or shorter; flowers few, scattered, mostly 



solitary and axillary; petals pink or red, 4 to 6 mm. long; 



carpels mucronate or short-cuspidate 6. A. parvulum. 



3. Carpels mostly 7 or more (7). 



7. Stems more or less woody above the caudex; leaf blades not more and 

 usually less than 10 cm. long, the basal sinus open; carpels cuspi- 

 date (8). 

 8. Leaves very shallowly cordate, the sinus usually much less than 1 cm. 

 deep; petals light orange yellow, little surpassing the calyx; stems, 

 leaves, calyx, and carpels stellate-canescent or tomentulose. 



7. A. CALIFORXICUM. 



8. Leaves more deeply cordate, the sinus usually 1 to 2 cm. deep ; petals rich 



orange, about twice as long as the calyx; calyx and carpels (and 

 usually the stems) villous; leaf blades velvety-tomentose. 



8. A. PALMERI. 



7. Stems herbaceous above the caudex, stout, tall, usually 90 cm. long, 

 or longer; leaf blades usually 10 cm. long or longer, very deeply 

 cordate, the sinus often closed and 1.5 to 3 cm. deep on the lower 

 leaves; flowers in long, nearly naked, terminal panicles; petals light 

 orange or yellow, much surpassing the calyx; calyx and carpels stellate- 

 canescent (9). 



9. Stems and petioles sparsely to copiously hirsute with long, spreading or 



reflexed hairs; carpels mucronate or cuspidate-. 9. A. soxorae. 



9. Stems and petioles glabrous or puberulent; carpels muticous or 



nearly so 10. A. reventum. 



