66 
Spring Flora of Oklahoma 
greenish or whitish regular flowers in axillary, peduncled 
heads or spikes. Flowers perfect, or the lowest some¬ 
times staminate. Calyx campanulate, its teeth short. 
Petals distinct or slightly united. Stamens 10 or 5, dis¬ 
tinct. Pod linear, straight or curved, several-seeded, 2- 
valved. 
1. Acuan illionerasis (Michx.) Kuntze. Illinois Mimosa. Stems 
erect or ascending, glabrous, angled. Leaves short-petioled, bi-pin- 
nate. Pinnae 5-15 pairs, sessile. Leaflets 10-24 pairs, sometimes 
more, sessile, obtuse. Pods numerous, densely capitate, oblong or 
lanceolate, strongly curved 8"-12" long, acute, slightly appressed be¬ 
tween the 2-5 seeds. 
Prairies and river banks. May-September. Common. 
III. MORONGIA Britton. 
Decumbent, perennial herbs or shrubs with re-curved 
prickles on leaves and stems. Leaves bi-pinnate, usually 
sensitive. Leaflets numerous, small. Flowers pink in a 
globose head. Pod linear; spiny all over, at length 4- 
valved, several-seeded. 
1. Morcngia uncinata (Willd.) Britton. Sensitive-bkier. Herb¬ 
aceous, perennial, branched, decumbent. Stem, branches, petioles, 
and peduncles armed with hooked prickles. Stem grooved and angled. 
Pinnae 4-8 pairs. Leaflets 8-15 pairs, obliquely elliptic, obtusish, and 
mucronate at the apex, inequilateral and rounded at the base, slightly 
ciliate on the margin. Head globose, very dense. Flowers pink. 
Pods terete, very densely spiny, about 2' long. 
Dry soil. May-July. Common. 
IV. NEPTUNIA Lour. 
Perennial herbs or shrubby plants, with unarmed pros¬ 
trate or diffused stems. Leaves with 2-pinnate blades. 
Leaflets small. Flowers perfect or polygamous, in head¬ 
like or cylindric spikes on solitary, axillary peduncles. 
Calyx 5 lobed. Corolla of 5 distinct or partially-united 
petals. Stamens 10, or rarely 5, exserted. Filaments dis¬ 
tinct. Ovary stipitate. Ovules several. Pod relatively 
broad, flat, oblique, 2-valved. 
1. Neptunia lutea (Leavenw.) Benth. Stems branched at the 
base, the branches prostrate, somewhat shaggy pubescent. Leaves 
