WOOTON AND STANDLEY FLORA OF NEW MEXICO. 327 



2. PRUNUS L. Plum. 



Low, treelike or spreading shrubs, 3 meters high or less, forming thickets; branches 

 stout, rigid, somewhat spiny; bark grayish; leaves sharply serrate; flowers white, 

 produced before the leaves; fruit ellipsoidal, red, the stone flattened, acute on both 

 edges. 



KEY TO THE SPECIES. 



Leaves pubescent beneath; petals 4 to 6 mm. long 1. P. watsoni. 



Leaves glabrous; petals 8 to 16 mm. long 2. P. americana . 



1. Prunus -watsoni Sarg. Gard. & For. 7: 134./. 25. 1894. Sand plum. 

 Prunus angustifolia watsoni Waugh, Rep. Vt. Agr. Exp. Sta. 12: 239. 1899. 

 Type locality: Ellis, Kansas. 



Range: Nebraska to Texas and eastern New Mexico. 



New Mexico: Nara Visa {Fisher 205). Plains, in the Upper Sonoran Zone. 



2. Prunus americana Marsh. Arb. Amer. 111. 1785. Wild plum. 

 Type locality: Not definitely stated. 



Range: Montana and New York to Florida and New Mexico. 



New Mexico: Taos; Pecos; Farmington; White Mountains. 



In some parts of the State this plum is almost certainly native; in other places it 

 may have been introduced. At Taos the trees are abundant and the fruit is gathered 

 by the Indians. At Farmington the small trees are very numerous along some of the 

 irrigating ditches. 



Some similar species has escaped rather abundantly near Mesilla. 



3. CEE-ASTJS L. Cherry. 



A small slender tree 3 to 4 meters high, with smooth purplish or reddish brown bark, 

 slender virgate branches, and corymbose white flowers; leaves 3 to 5 cm. long, oblong- 

 elliptic, slightly attenuate to the base, acute or abruptly short-acuminate, crenulate, 

 on petioles 1 cm. long or less; corymbs about 4-flowered; hypanthium campanulate, 

 glabrous; petals small, white; fruit ovoid, red; stone ovoid. 



1. Cerasus crenulata Greene, Proc. Biol. Soc. Washington 18: 56. 1905. 



Type locality: West Fork of the Gila, Mogollon Mountains, New Mexico. Type 

 collected by Metcalfe (no. 587). 



Range: Mountains of southwestern New Mexico. 



New Mexico: Mogollon Mountains; Hillsboro Peak. Transition Zone. 



The fruits when ripe are a bright cherry red, ellipsoidal, 1 cm. long or less, and de- 

 cidedly acid as well as somewhat astringent. 



67. MIMOSACEAE. Mimosa Family. 



Shrubs or suffrutescent perennials with usually spiny stems and bipinnate leaves with 

 usually numerous small leaflets; flowers regular, small, in axillary pedunculate heads 

 or spikes; calyx 4 or 5-parted (sometimes wanting in Acuan); corolla of 4 or 5 distinct 

 or united petals; stamens 5 to 10 or numerous, distinct or united; fruit a more or less 

 flattened, dehiscent or indehiscent legume. 



KEY to the genera. 



Stamens numerous, always more than 10, distinct or 

 monadelphous. 

 Corolla gamopetalous, tubular; stamens monadel- 

 phous; low plants with unarmed stems 1. Calliandra (p. 328). 



Corolla polypetalous; stamens distinct; plants more 

 or less shrubby and spiny (except in A. cus- 

 pidata) 2. Acacla. (p. 328). 



