530 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



7. Amyris sylvatica Jacq. Stirp. Ainer. 107. 1763. 



Veracruz and perhaps elsewhere. Central America, West Indies, and north- 

 ern South America ; type from Cartagena, Colombia. 



Glabrous shrub or tree, 2 to 9 meters high ; leaflets crenate, bright green ; 

 fruit 4.5 to 7 mm. long, black or reddish. "Tea " (Porto Rico). 



8. Amyris thyrsiflora Turcz. Bull. Soc. Nat. Moscou 31 ': 475. 1858. 

 Veracruz. 



Glabrous shrub or tree ; leaflets crenate or entire, coriaceous, lustrous ; flowers 

 white, fragrant. 



6. EUYTHROCHITON Nees & Mart. Nov. Act. Acad. Caes. Leop. Carol. 11: 



151. 1823. 



1. Erythrochiton lindeni (Bail!.) Hemsl. Biol. Centr. Amer. Bot. 1: 166. 1879. 



Toxosiphon lindeni Baill. Adansonia 10: 312. 1872. 



Tabasco ; type from Teapa. Central America. 



Shrub, about 2 meters high ; leaves long-petiolate, the leaflet 1, oval or elliptic, 

 10 to 35 cm, long, entire, glabrous ; flowers white, in scorpioid cymes, the sepals 

 2 to 4 cm. long, 



7. THAMNOSMA Torr. & Fri^m. in Fr&m. Rep. Exped. Rocky Mount. 313. 1845. 



Erect shrubs or sometimes herbs ; leaves alternate, linear or reduced to scales, 

 entire ; flowers smaii, racemose ; fruit a 2-lobed capsule. 



Petals 3 to 5 mm. long; leaves present; seeds 1.5 to 2 mm. long — 1, T. texana. 

 Petals 8 to 14 mm. long : leaves usually absent ; seeds 4 to 6 mm, long 



2. T. montaua. 



1. Thamnosma texana (A. Gray) Torr. U. S. & Mex. Bound. Bot. 42. 1859. 

 Rutosma texana A. Gray, Gen. Fl. Amer. 2: 144. 1849. 



Chihuahua to Nuevo Le6n and San Luis Potosi. Western Texas (type local- 

 ity) to Colorado and Arizona. 



Slender shrub, 50 cm, high or less, or often herbaceous ; leaves linear, 5 to 

 15 mm. long; flowers yellowish or purplish. 



2. Thamnosma montana Torr. & Frem. Rep. Exped. Rocky Mount. 313. 1845. 

 Northern Baja California and probably northern Sonora. California to 



Arizona and Utah ; type from Nevada. 



Glandular shrub, 30 to 60 cm. high, the branches often spinose, yellowish 

 green ; leaves 5 . to 10 mm. long but early deciduous ; flowers purple. " Cor- 

 doncillo " ( Arizona ) . 



A decoction of the plant is used by the Pima and Apache Indians as a rem- 

 edy for gonorrhoea, and in Arizona it is employed as a general tonic and 

 blood purifier. 



8. HEIilETTA Tulasne, Ann. Sci. Nat. III. 7: 280. 1847. ■ 



1. Helietta parvifolia (A. Gray) Benth. in Hook. Icon. PI, 14: 66, 1882, " 



Ptelea parvifolia A, Gray; Herasl, Biol. Centr. Amer. Bot. 1: 170. 1879. 

 Coahuila to Tamaulipas and Queretaro; type from Carrizal, Nuevo Leon. 

 Western Texas. 



Shrub or tree, sometimes 8 meters high, with a slender trunk 15 cm. in dia- 

 meter ; bark thin, dark brown, scaly ; leaves opposite, persistent, digitate, the 

 leaflets 3, obovate, 1 to 5 cm. long, obtuse, usually entire, glabrous, flowers 

 small, white, cymose; fruit 6 to 8 mm. long, with thin wings; wood hard, close- 

 grained, orange-brown, the specific gravity about 0.88. " Barreta " (Nuevo Le6n, 

 Tamaulipas, Coahuila, Texas), 



i 



