STANDLEY ALLIONIACEAE OF MEXICO. 395 



The glabrous Bougainvillea perhaps hardly deserves specific rank. It is impossible 

 to draw any sharp line between the two forms. Like B. spectabilis it is not a native 

 of any part of North America, unless it is the southernmost region, but it is widely 

 cultivated and sometimes seems to have escaped. 



8. TRIPTEROCALYX Hook. 



Tripterocalyx Hook. Journ. Bot. Kew Misc. 5: 261. 1853. 



Cycloptera Nutt.; A. Gray, Amer. Journ. Sci. II. 15: 319. 1853, not Endl. 1841. 



Apaloptera Nutt.; A. Gray, loc. cit. 



Type species, Abronia micrantha Torr. 



1. Tripterocalyx cyclopterus (A. Gray) Standley, Contr. Nat. Herb. 12: 329. 1909. 

 Abronia cycloptera A. Gray, Amer. Journ. Sci. II. 15: 319. 1853, excluding syn- 

 onyms. 

 Abronia carnea Greene, Pittonia 3: 343. 1898. 



Type locality, "On the Bio Grande, New Mexico." Type collected by Charles 

 Wright (no. 1712). 

 Specimens examined: 



Chihuahua: Sandhills near Paso del Norte (Ciudad Juarez), 1885, Pringle 75; 

 Sabinal, Sierra Madre, alt. 1,290 meters, September 29, 1903, Jones. 



9. ABRONIA Juss. 



Abronia Juss. Gen. 448. 1789. 



Tricratus L'Her.; Willd. Sp. PL 1: 807. 1799. 



Type species, Abronia umbellata Lam. 



The Abronias are known in Mexico under the names of alfombrilla de los arenales 

 and alfombrilla de la playa. The roots of A. maritima are said to be eaten sometimes 

 by the Indians. 



KEY TO THE SPECIES. 



Stems erect or strongly ascending; perianth greenish white 1. A.fendleri. 



Stems prostrate or merely ascending; perianth purplish red. 



Flowers of a deep, dark red; fruit strongly coriaceous 2. A. maritima. 



Flowers much paler, purplish red; fruit with thin walls and 

 wings. 



Anthocarp not winged but 5-lobed 3. A. torreyi. 



Anthocarp 5- winged. 



Wings of the fruit much narrowed below, the body 

 strongly ribbed or pitted; leaf blades not sinu- 

 ate-margined 4, A. villosa. 



Wings of the fruit slightly if at all narrowed below, the 

 body smaller and not ribbed or pitted; leaf 

 blades more or less sinuate. 

 Leaf blades only slightly sinuate; plant stout; 



fruit 10 to 12 mm. long, its wings thin 5. A. platyphylla. 



Leaf blades strongly sinuate, narrower; fruit 7 mm. 



long or less, its wings comparatively thick . . 6. A . gracilis. 



1. Abronia fendleri Standley, Contr. Nat. Herb. 12: 324. pi. 43. 1909. 



Type locality, "Santa Fe, New Mexico." Type collected in 1847, Fendler 739. 

 Specimens examined: 



Chihuahua: On sandhills near Paso del Norte (Ciudad Juarez), September 20, 

 1886, Pringle 794. 

 As stated when the species was published, the plants from the southern part of the 

 Rio Grande Valley are not typical fendleri and may be specifically distinct. The 



