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what incurved, slipper-shaped and laterally compressed, the cavity 
divided at apex by a crest-like partition), mainly alternate or scattered 
leaves, solitary and terminal or corymbed loosely-flowered umbels, and 
oblong or ovate pods (often with soft spinous projections). 
1. A. viridis Gray. Almost glabrous: stems short, 3 dm. high: leaves short-petioled, 
ovate-oblong to lanceolate, 2.5 to 5 em. wide: umbels several in a cluster, short- 
peduncled: flowers large (2.5 cm. broad), with purplish hoods. (Acerates paniculata 
Decaisne.)—Prairies and dry barrens, extending from north and east through Texas 
to New Mexico. 
2. A. decumbens Gray. Scabrous-puberulent: leaves from lanceolate to linear, 
tapering to the apex: umbel solitary: flowers 8 to 10 mm. long, with yellowish or 
dark-purplish hoods.—Dry plains, throughout Texas. 
3. ASCLEPIAS L. (MILKWEED. SILKWEED.) 
Perennial upright herbs, with peduncles terminal or lateral (and be- 
tween usually opposite petioles) bearing simple many-flowered umbels, 
5-parted persistent calyx with small reflexed divisions, deeply 5-parted 
corolla with reflexed deciduous divisions, crown of 5 hooded bodies seated 
on the stamen-tube and each containing an incurved horn, 5 stamens 
inserted on base of corolla with filaments united in a tube which en- 
closes the pistil, anthers adherent to the stigma (each with 2 vertical 
cells, tipped with a membranaceous appendage, each cell containing a 
flattened pear-shaped and waxy pollen-mass; the two contiguous pol- 
len-masses of adjacent anthers forming pairs which hang by a slender 
prolongation of their summits from 5 cloven glands that grow on the 
angles of the stigma), 2 ovaries tapering into very short styles and with 
a large depressed 5-angled fleshy stigmatic disk in common, 2 pods (one 
often abortive), and flat margined seeds bearing a tuft of long silky 
hairs (coma) and downwardly imbricated all over the large placenta. 
* Hood sessile, broader or at least not attenuate at base ; horn conspicuous: anther-wings 
broadest and usually angulate-truncate and salient at base. 
+ Flowers orange-color : leaves mostly scattered, 
1. A.tuberosa L. (BuTrERFLY-WEED. PLeuRIsy-roor.) Roughish-hairy, 3 to 
6 dm. high: stems very leafy, branching at summit, and bearing usually numerous 
umbels in a terminal corymb: leaves from linear to oblong-lanceolate, sessile or 
slightly petioled: hoods narrowly oblong, bright orange, scarcely longer than the 
nearly erect and slender awl-shaped horns: pods hoary, erect on deflexed pedicels.— 
Dry and usually sandy soil, throughout Texas. 
+ + Flowers bright red or purple: pods naked, fusiform : leaves opposite. 
2. A. paupercula Michx. Glabrous: stem slender, 6 to 12 dm. high: leaves elon- 
gated-lanceolate or linear, transversely veined, tapering to both ends, slightly peti- 
oled: umbels 5 to 12-flowered: divisions of red corolla narrowly oblong; hoods bright 
orange, about 6 mm. long, exceeding the anthers and much exceeding the incurved 
horn: pods erect on deflexed pedicels.—Marshes near the coast. 
3. A.incarnata L. (SWAMP MILKWEED.) Smooth or nearly so, the stem with 
two downy lines above and very leafy: leaves oblong-lanceolate, acute or pointed, 
obtuse or obscurely heart-shaped at base, with ascending veins: flowers rose-purple ; 
hoods 2 mm. long, equaling the anthers and scarcely equaling the slender needle- 
pointed horn: pods erect on erect pedicels.—A common swamp species of the Atlan- 
tic region, represented in Texas by var, LONGIFOLIA Gray, which has glabrous or 
