WOOTON AND STANDLEY FLOKA OF NEW MEXICO. 401 



Range: British America to Texas and Mexico. 



New Mexico: Shiprock; Dulce; Tunitcha Mountains. Sandy soil, in the Upper 

 Sonoran Zone. 



18, Chamaesyce rugulosa (Engelm.) Rydb. Bull. Torrey Club 33: 145. 1906. 

 Euphorbia serpyllifolia rugulosa Engelm.; Millsp. Pittonia 2: 85. 1890. 

 Type locality: San Bernardino, California. 

 Range: California to Colorado and New Mexico. 

 New Mexico: Dulce {Standley 8135). Open hills, in the Upper Soiioran Zone. 



7. REVERCHONIA A. Gray. 



Slender, smooth, divaricately branched annual, 30 cm. high or less, with glaucous 

 stems, narrow entire leaves, and small axillary clusters of dark purple flowers; stam- 

 inate flowers with 4 sepals and 2 short stamens; pistillate flowers with 5 sepals and a 

 6-lobed disk; ovary 3-celled; styles 3, distinct; fruit a dry capsule. 



1. Reverchonia arenaria A. Gray, Proc. Amer. Acad. 16: 107. 1881. 



Type locality: Sandhills of the Brazos, Baylor County, Texas. 



Range: Texas and southern New Mexico, south into Mexico. 



New Mexico: Lava; sands northeast of Jornada Range, Dona Ana County; Roswell. 

 Dry hills and plains, in the Lower Sonoran Zone. 



8. PHYLLANTHTJS L. 



Low herbaceous perennial from a woody base, 10 to 20 cm. high, with slender 

 smooth stems, small leaves, and very small greenish flowers; leaves narrowly oblong- 

 cuneate, with lanceolate stipules at the base of the short petiole; flowers in axillary 

 few-flowered clusters, monoecious; staminate flowers about 0.5 mm. long, the pistillate 

 about 3 times as large, on very slender pedicels; sepals 5 or 6, green, white-margined, 

 persistent at the base of the 3-celled 6-valved 3-seeded capsule. 



1. PhyUanthus polygonoides Nutt.; Spreng. Syst. Veg. 3: 23. 1826. 



Type locality: "Ditio Arcansa Amer. bor." 



Range: New Mexico to Texas and Oklahoma. 



New Mexico: Organ Mountains; Queen; Hatchet Ranch. Dry, rocky hillsides, 

 in the Upper Sonoran Zone. 



9. JATROPHA L. 



Herbaceous perennial from a thickened tuberous root; stems thick and succulent, 

 30 to 50 cm. high, erect; leaves petiolate, palmately 3 to 5-lobed, 10 cm. in diameter 

 or less, the lobes triangular-lanceolate, with rather numerous coarse aristate teeth; 

 stipules, bracts, and sepals laciniately lobed into linear segments; flowers large, in a 

 terminal cyme; sepals 5, united below; petals 5, bright pink, about 1 cm. long; fila- 

 ments united below, unequal; fruit a 3-celled capsule, each 2-valved cell containing 

 a single large carunculate seed. 



1. Jatropha macroi'hiza Benth. PI. Hartw. 8. 1839. 

 Type locality: Mexico. 



Range: Southern New Mexico and Arizona to Mexico. 

 New Mexico: Southern Grant and Luna counties. Sandy plains, in the Lower 



Sonoran Zone. 



10. DITAXIS Vahl. 



Monoecious herbaceous perennials with simple alternate leaves and axillary clusters 

 of flowers; staminate flowers with 4 or 5 sepals, the petals of the same number and 

 alternate with them; stamens once, twice, or thrice the number of the petals, with 

 united filaments; petals of the pistillate flowers smaller or rudimentary; styles 3, 

 2-cleft; fruit a 3-seeded capsule; seeds globose. 

 52576°— 15 26 



