178 MILKWEED FAMILY 



cross-pollination devices are more astonishing than those 

 seen in these peculiar flowers, in which the five stamens 

 form a palisade around the flat-topped pistil, a palisade 

 whose only openings are minute slits. An insect alights 

 on the smooth and slippery upper part of the flower, and 

 in struggling for foothold a leg slides into one of these 

 openings, within which is a clip to which pollen masses 

 are attached. When the foot is withdrawn the clip shuts 

 down on the leg, and the insect, willy-nilly, must carry 

 off the clip with the pollen, or, as sometimes happens, leave 

 a leg torn off in the slit. At the next flower visited the 

 same adventure results in the pollen carried by the insect 

 being brought in contact with the stigma, while fresh 

 pollen is fastened on the insect's leg. 



The peculiar form of the flowers in the common milk- 

 weeds is characteristic of other genera, in various modifi- 

 cations. Within the petals is a short crown of five erect 

 hoodlike processes, each of which in the genus Asclepias 

 (but not in our other genera) bears a small incurved 

 horn. 



Milkweeds begin to bloom in February in Florida. The 

 most showy of the early species is the butterfly-weed, 

 Asclepias tuberosa, also called pleurisy-root from its for- 

 mer use in medical practice. This is followed by the 

 prostrate or spreading A, humistrata, with ash-colored 

 flowers, and broad leaves of pale green veined with white 

 and rose, and by the erect A. tomentosa, whose many 

 clusters of greenish flowers are set among dark green, 

 wavy-margined leaves. The tall red milkweed, A. lanceo- 

 lata, blooms in summer in marshy places, and other less 

 showy species are found in different locations. 



The delicate and attractive Asclepiodora Feayi is said 

 to have been used by the Seminoles as a remedy for 

 snake-bites. 



Several twining vines of this family grow near the 

 coast — climbing over shrubs, and lying in tangled mats 



