182 FOUNDATIONS OF BOTANY 
greenish ; hoods white, with 2 teeth; horns with an awl-shaped 
point extending far out of the hoods. Damp thickets N. and E. 
4. A. variegata, L. Wuitre MILKWeEEp. Stem stout, leafless 
and smooth below, leafy and downy in lines above. Leaves oppo- 
site, the middle ones sometimes in fours, petioled, ovate to obovate, 
Fic. 20. — Flower of Asclepias Cornuti. 
A, entire flower ; B, vertical section ; C, diagram; D, details of pollen-masses 
and glands. ca, calyx; c, corolla; hd, hood; hn, horn; a, anther; s, stig- 
ma; 0, ovary ; g, gland; p, pollen-mass. (All considerably enlarged.) 
cuspidate, smooth on both sides, pale beneath, edges slightly crenate. 
Umbels 1-5, compact, downy, 1-2 in. long ; pedicels erect, as long 
as the peduncles. Corolla white, often purple at the base; hoods 
roundish, spreading, a little longer than the thick, awl-pointed, 
incurved horn. Dry, open woods E. and S.* 
5. A. quadrifolia, L. Four-LEAveED MILKWEED. Stem slender, 
13-2 ft. or more high, usually leafless below. Leaves in1 or 2 
