60 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



19. CHAETOCHLOA Scribn. 



Annuals or perennials with flat leaves and bristly spikelike panicles; spikelets^ 

 hermaphrodite, 1-flowered, or sometimes with a staminate flower below the hermaphro- 

 dite terminal one, surrounded by few or many persistent awnlike branches springing 

 from the pedicels below the articulation of the spikelets; glumes awnless; stamens 3; 

 styles distinct; grain included within the hardened lemma and palea, free. 



KEY TO THE SPECIES. 



Panicles dense and thick. 



Spikelets arranged singly in racemes; 5 to 16 bristles at the base 



of each spikelet 1 . C. glauca. 



Spikelets clustered but not in racemes; 1 to 3 bristles at base of 



each spikelet 2. C. viridis. 



Panicles slender, interrupted. 



Leaf blades more than 5 mm. wide; spikes with distinct, some- 

 what spreading branches below 3. C. grisebachii 



ampla. 

 Leaf blades less than 5 mm. wiilo; spikes not branched below, 



merely interrupted 4. C. composita. 



1. Chaetochloa glauca (L.) Scribn. U. S. Dept. Agr. Div. Agrost, Bull. 4: 39. 1897. 



Pigeon grass. 

 Panicum glaucum L. Sp. PI. 56. 1753. 

 Setaria glauca Beauv. Ess. Agrost. 51. 1812. 

 Type locality: "Habitat in India." 



Range: A native of the Old World, widely introduced into North America, in New 

 Mexico still rare. 

 New Mexico: Kingston; Mesilla Valley; Roswell. 



2. Chaetochloa viridis (L.) Scribn. U. S. Dept, Agr. Div. Agrost. Bull. 4: 39. 1897. 



Green foxtail. 



Panicum viride L. Sp. PI. ed. 2. 83. 1762. 



Setaria viridis Beauv. Ess. Agrost. 51. 1812. 



Type locality: "Habitat in Europa australi." 



Range: Native of Europe, widely introduced into North America; in New Mexico 

 a common weed in cultivated fields. 



New Mexico: Common in waste and cultivated ground in nearly every part of 

 the State. 



3. Chaetochloa grisebachii ampla Scribn. it Merr. U. S. Dept. Agr. Div. Agrost. 



Bull. 21: 36. 1900. 

 Type locality: Organ Mountains, New Mexico. Type collected by G. R. Vasey. 

 R,ange: New Mexico and Arizona to northern Mexico. 



New Mexico: Mangas Spi'ings; Hillsboro; Rio Frisco; Burro Mountains; Organ 

 Mountains; Tortugas Mountain. Damp canyons, in the Upper Sonoran Zone. 



4. Chaetochloa composita (H. B. K.) Scribn. U. S. Dept, Agr. Div. Agrost. Bull. 



4: 39. 1897. 



Setaria composita H. B. K. Nov. Gen. & Sp. 1: 111. 1816. 



Type locality: "Crescit regione calidissima prope Cumana et Bordones, in Nova 

 Andalusia: item in ripa fluminis Magdalenae prope Guarumo et in sylvis Orinocen- 

 sibus juxta Esmeralda." 



Range: Colorado and Arizona to Texas and Mexico; also in South America. 



New Mexico: Cross L Ranch; Albuquerque; Chiz; Animas Creek; Mangas Springs; 

 Lake Valley; Aden; Rincon; Burro Mountains; Mesilla Valley; Guadalupe Mountains; 

 Pecos Valley. River valleys and low hills, in the Lower and Upper Sonoran zones. 



