366 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



66. Mimosa lemmoni A. Gray, Proc. Amer. Acad. 19: 76. 1883. 



Northern Chihuahua and Sonora. Southern New Mexico and Arizona ; type 

 from Huachuca Mountains, Arizona. 



Shrub, about 1 meter high, very pubescent ; fruit densely pubescent, unarmed 

 or nearly so, about 6 mm. wide. 



67. Mimosa aculeaticarpa Ortega, Hort. Matr. Dec. 134. 1800. 

 Mimosa acanthocarpa Benth. in Hook. Journ. Bot. 4: 409. 1842. 



Mimosa acanthocarpa desmanthocarpa Robinson, Proc. Amer. Acad. 36: 472. 



1901. 

 Mimosa aculeaticarpa impariUs Macbride, Contr. Gray Herb. n. ser. 59: 12. 



1919. 

 San Luis PotosI to Tepic, Chiapas, and Hidalgo. 



Shrub or small tree, armed with numerous spines ; flowers white or pink ; 

 fruit usually spiny on the margins, about 6 mm. wide, reddish brown. 



Mimosa acanthocarpa desmanthocarpa is a form with unarmed fruit. M. 

 acaleaticarpa impariUs has glandular and hirsute branchlets. 



DOUBTFUL SPECIES. 



Mimosa abcuata Mart. & GaL Bull. Acad. Brux. 10^: 308. 1843. Type from 

 TehuacSn, Puebla. According to Robinson, probably a synonym of M. Muncifera 

 Benth. 



Mimosa geminata DC. Prodr. 2: 427. 1825. Described from Mexico. 



Mimosa tbicephala Cham. & Schlecht. Linnaea 5: 591. 1830. Type from 

 Actopan, Hidalgo. 



7. ACUAN Medic. Theod. Sp. 62. 1786. 



Low suffrutescent or herbaceous plants, unarmed ; leaves bipinnate, the 

 leaflets numerous, small, the stipules setaceous, persistent ; flowers in dense 

 heads ; fruit linear, compressed. 



Several other species of the genus occur in Mexico, but they are herbaceous 

 plants. 



Fruit 3 to 5 mm. wide 1. A. virgatum. 



Fruit 5 to 6 mm. wide 2. A. fruticosum. 



1. Acuan virgatum (L.) Medic. Theod. Sp. 62. 1786. 

 Mimosa virgata L. Sp. PI. 519. 1753. 

 Desmanthus virgatus Willd. Sp. PI. 4: 1047. 1806. 



Sonora to San Luis PotosI, Vei*acruz, and Oaxaca. Widely distributed in 

 tropical America. 



More commonly, perhaps, a herbaceous plant, but often a shrub 1 to 3 meters 

 high ; leaflets 2 to 4 mm. long, oblong, obtuse ; flowers white ; fruit 4.5 to 10 

 cm. long, glabrous. 



2. Acuan fruticosum. (Rose) Standi. 



Desmanthus fruticosus Rose, Contr. U. S. Nat. Herb. 1: 131. pi. 13. 1892. 

 Baja California ; type from Carmen Island. 



Slender shrub, 1.5 to 3 meters high ; leaflets oblong, 5 to 9 mm. long ; fruit 

 4 to 8 cm. long. 



8. LEUCAENA Benth. in Hook. Journ. Bot. 4: 416. 1842. 



Unarmed trees or shrubs; leaves bipinnate, the leaflets few and large or 

 numerous and small, the petiole usually glanduliferous ; stipules small ; flowers 

 in dense globose heads, white ; fruit flat, stipitate, bivalvate. 



Some of the South American species are said to be employed to poison or 

 stupefy fish. 



