Spring Flora of Oklahoma 
65 
of as many distinct or more or less united petals. Sta¬ 
mens 5-10-many, distinct or united. Ovary 1-celled. 
Ovules several or numerous. Fruit a more or less flat¬ 
tened, dehiscent or indehiscent legume. 
Stamens numerous, at least more than 10. I. Acacia. 
Stamens only as many as the petals, or twice as many. 
Anthers without glandular appendages at the top. 
Petals separate; pod smooth. II. Acuan. 
Petals united to about the middle; pod spiny. 
III. Morongia. 
Anthers, at least in the bud, topped by glandular ap¬ 
pendages. 
Herbs; pods flat and thin, twice or thrice longer 
than broad. IV. Neptunia. 
Shrubs or trees; pods relatively thick, many times 
longer than broad. V. Prosopis. 
I. ACACIA L. 
Shrubs or low trees with armed or smooth stems and 
numerous very small leaflets. Flowers small, regular, in 
spikes or heads on axillary peduncles. Corolla of 4 or 5 
similar petals; petals united, separate or wanting. Sta¬ 
mens numerous, distinct, exserted. Pods flattened or 
terete, 2-valved, dehiscent. 
1. Acacia angustissima (Mill.) Kuntze. Prairie Acacia. Low, 
thornless shrub, varying from glabrous to hirsute-pubescent. Pinnae 
of the leaves 2-15 pairs, oblong in outline, l'-2' long. Leaflets 10-50 
pairs, oblong or linear-oblong, about 2" long, less than 1" wide, 
slightly inequilateral, 1-veined. Heads globose, axillary, 6"-10" in 
diameter. Filaments yellow, 3-4 times as long as the sepals. Pod 
linear, acute, often narrowed at the base, mostly straight, l'-2' long, 
about 3" wide, flat, its valves thin, impressed between the seeds. 
Prairies. May-July. Common. 
II. ACUAN Medic. 
Perennial herbs or shrubs, with bi-pinnate leaves, £.nd 
