Elementary botany . Fig. of flower of cypripedium. sf,stigma ; a, at the left stamen. The insectenters the labellum at the center, passesunder and against the stigma, and outthrough the opening b, where it rubsagainst the pollen. In passing throughanother flower this pollen is rubbed offon the stigma. must be deposited on the stigmatic end or marginin order that fertilization may take place. 862. If we open carefully canna-flower budswhich are nearly ready to open naturally, byunwrapping the folded petals and staminodia, we shall see the anther-bearing Fig. Fig. 4
Elementary botany . Fig. of flower of cypripedium. sf,stigma ; a, at the left stamen. The insectenters the labellum at the center, passesunder and against the stigma, and outthrough the opening b, where it rubsagainst the pollen. In passing throughanother flower this pollen is rubbed offon the stigma. must be deposited on the stigmatic end or marginin order that fertilization may take place. 862. If we open carefully canna-flower budswhich are nearly ready to open naturally, byunwrapping the folded petals and staminodia, we shall see the anther-bearing Fig. Fig. with portion of perianth removed to show details. /, labellum ; sf, stigma; r,rostellum; /, pollinium. When the insect approaches the flower its head strikes the diskof the pollinium and pulls the pollinium out. At this time the pollinium stands up out of theway of the stigma. By the time the insect moves to another flower the pollinia have moveddownward so that they are in position to strike the stigma and leave the pollen. At theright is the head of a bee, with two pollinia (a I attached. 448 RELATION TO ENVIRONMENT, staminodium is so wrapped around the flattened style that the anther lies closely pressed against the face of the style, near the margin opposite that on which the stigma lies. 863. The walls of the anther locules which lie against the style become changed to a sticky substance for their entire length, so that they cling firmly to the surface of the styleand also to the mass of pollenwithin the locules. The result isthat when the flower opens, andthis
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Keywords: ., bookauthoratk, bookcentury1900, bookdecade1900, booksubjectbotany
