88 
Spring Flora of Oklahoma 
1. Xanthoxylum ammcanum Milo. Prickly Asii. Toothache- 
tree. A prickly, aromatic shrub. Leaves alternate, odd-pinnate. 
Leaflets 3-11, ovate, opposite, nearly sessile, l%'-2' long. Flowers 
greenish, in the sessile, axillary cymes, borne on the wood of the 
previous season and appearing before the leaves. Calyx none. Petals 
4 or 5. Pistils 2-5. Follicles black, about 2" long. 
In woods and thickets. April-May. 
II. PTELEA L. 
Shrubs or small trees, without prickles. Leaves 3-5- 
foliolate, with entire or serrulate leaflets. Flowers green¬ 
ish-white, polygamous, corymbose-paniculate. Calyx 4- 
5-parted, imbricated. Petals 4-5, imbricated. Stamens 
4-5, alternate with the petals. Ovary flattened, 2-celled. 
Fruit a nearly orbicular samara, 2-winged. 
1. Ptelea trifoliata L. Three-leaved Hop-tree. A shrub. 
Leaves long petioled, 3-foliolate. Leaflets ovate or oval, 2'-5' long, 
sessile, crenulate. Flowers in terminal, compound cymes. Odor dis¬ 
agreeable. Samara 8"-9" in diameter, the wing membranous and 
reticulated, emarginate. 
In woods and rocky soil. May-June. Kingfisher-Comanche 
counties. 
FAMILY 45. POLYGALACEAE. Milkwort Family. 
Herbs or shrubs with simple or entire leaves and no 
stipules. Flowers mostly small, papilionaceous in ap¬ 
pearance. Sepals 2 to 5. Petals 3. Stamens monodel- 
phous or diadelphous, with 1-celled anthers opening with 
a terminal pore. Pods flat, 1 or 2-celled. 
I. POLYGALA (Tourn.) L. 
Low herbs or shrubs with solitary or racemose flowers 
and small simple leaves. Sepals 5, the 2 lateral ones 
large and petaloid. Petals 3, united to each other and to 
the stamen tube, the middle one often crested and append- 
aged. Stamens 6 or 8. Pod 2-celled, flattened contrary to 
the partition, sometimes winged. 
