STANDLEY TREES AND SHRUBS OF MEXICO. 99 



food for cattle, especially in time of drought. In New Mexico and westoi'n 

 Texas the plants have been used on a large scale for this purpose, often 

 after having been transported by railroad. The plants were formerly much used 

 for food, by the natives of the arid regions, and are still so used to some extent. 

 The leaves are trimmed off and the remaining head is roasted or boiled and 

 the sweet pith and leaf bases then eaten. The heads are often baked for about 

 24 hours in pits dug in the ground. The roasted trunks are also allowed to 

 ferment and then distilled to obtain* a highly esteemed intoxicating drink known 

 as " sotol," which is a colorless liquor of penetrating odor and peculiar taste. 

 Alcohol has been extracjtpd from sotol plants upon a commercial scale. 



The leaves are much used for thatching, baskets, rough hats, mats, etc., and 

 their fiber for rough cordage. The fiber seems to be suitable for the manufac- 

 ture of paper. 

 Most of the species are known generally under the name " sotol." 



Leaves 4-sided, unarmed 16. D. longissimum. 



Leaves 2-edged, flattened or concave, with prickly mai'gins. 

 Fruit large (8 to 9 mm. wide), the style longer than the wings. 



15. D. berlandieri. 

 Fruit small or, if large, the style not exceeding the wings. 

 Fruit 3 to 5 mm. wide. 

 Fruit with a very shallow notch at the apex, broadly elliptic, the style 

 equaling or slighly exceeding the wings. Prickles of the leaves 

 antrorse. 

 Leaves 10 to 15 mm. wide. Inflorescence much branched. 



6. D. texanum. 

 Leaves 5 to 10 mm, wide. 



I^eaves about 1 nteter long 7. D. simplex. 



Leaves 40 to 50 cm. long 8. D. longistylum. 



Fruit with a rather deep notch, narrowly elliptic to obovate, the style 

 not surpassing the wings. Leaves usually 15 to 20 cm. wide. 



Prickles of the leaves mostly retrorse 5. D. leiophyllum. 



Prickles of the leaves mostly antrorse. 



Leaves 25 mm. wide or more 3. D. palmeri. 



Leaves 10 to 20 mm. wide. 



Leaves about 0.5 meters long, dull ; style nearly equaling the wings. 



4. D. parryanum. 

 Leaves about 1 meter long ; style half as long as the wings. 



Leaves dull, glaucous 1. D. cedrosanum. 



Leaves lustrous, not glaucous 2. D. lucidum. 



Fruit 6 to 8 mm. wide, the style not exceeding the wings. Prickles all or 

 mostly antrorse. 



Leaves not with brushy tips, glaucous 9. D. glaucophyllum, 



Leaves with more or less brushy tips. 



Leaves 1 cm. wide or narrower 10. D. acrotriche. 



Leaves mostly 1.5 cm. wide or wider, rarely only 1.2 cm. wide. 



Wings of the fruit truncate at the apex, with a very narrow notch ; 



leaves rough ._ 13. D. serratifolium. 



Wings of the fruit rounded or obtuse at the apex, with a broad notch ; 

 leaves smooth or nearly so. 



Leaves about 1.2 cm. wide 11. D. graminifoliuin. 



Leaves 1.5 to 2 cm. wide. 



Style scarcely half as long as the wings 12. B. durangense. 



Style about as long as the wings 14. D. wheeleri. 



