64 
Spring Flora of Oklahoma 
ly serrate leaves. Bark, leaves and seeds bitter with 
prussic acid. Flowers perfect, corymbose, umbelled, ra- 
cemed or solitary, regular. Calyx inferior, deciduous, 
free from the ovary, its tube obconic, campanulate, or 
tubular, 5-lobed. Petals 5, inserted on the calyx. Sta¬ 
mens numerous, inserted with the petals. Fruit a drupe. 
I. PRUNUS (Tourn.) L. 
Trees or shrubs. Leaves sharply serrate. Flowers 
white, produced before the leaves. Fruit fleshy, the stone 
flattened, acute on both edges. 
Leaves abruptly acuminate; drupe red or yellow. 
1. P. americana. 
Leaves acute or obtusish; drupe red or purple. 
2. P. gracilis. 
1. Primus americania Marsh. Wild Yellow or Red plum. A 
shrub or small tree. Branches more or less thorny. Bark thick. 
Leaves ovate or obovate, acuminate, usually pubescent when young, 
sharply and often doubly serrate, with gland-tipped teeth, rounded 
at the base, slender-petioled. Flowers white, 8"-12" broad, appear¬ 
ing in lateral, sessile umbels before the leaves. Drupe globose, red 
or yellow,' 9"-12" in greatest diameter. 
In thickets. April-May. 
2. Prunus gracilis Engelm. & Gray. Low Plum. A branching 
shrub, 12'-48' high, the foliage and young twigs densely soft-pubes¬ 
cent. Leaves short-petioled, ovate-lanceolate or oval, acute or acut- 
ish at both ends, sharply serrate, glabrate on the upper surface at 
maturity. Flowers white, 3"-4" broad, in sessile lateral umbels, 
appearing before the leaves. Drupe oval-globose, 4"-5" in diameter. 
In sandy or dry soil. Spring. 
FAMILY 36. MIMOSACEiE. Mimosa Family. 
Herbs, shubs or trees, with alternate, mostly com¬ 
pound, commonly 2-3-pinnate leaves, the stipules various, 
and small, regular, mostly perfect flowers, in heads, spikes 
or racemes. Calyx 3-6-toothed, or 3-6-lobed. The corolla 
