J. M. Macfarlanc. 



Sarraceniaceae. 



19 



Each flower in Sarracenia is subtended by three strongly convex bracts arranged 

 in spiral order, and which vary in color from green to yellow and crimson. They are 

 closely adpressed to the calyx, and have abundant honey glands over their outer surface. 

 The five sepals are disposed in 2 / 5 spiral order. They vary from green to yellow or 

 crimson in whole or in part. They are always unequal in size and of varying consistency. 

 The outermost sepal is broader, shorter and thicker than that next in spiral order, the 

 innermost is longest, narrowest and most delicate in consistence. Their surface is 

 covered to a varying degree with nectar glands that secrete a fair amount of nectar 

 during and even after the flowering period. 



The petals in Darlingtonia are of a reddish-yellow color, are traversed by H — 13 

 reddish-crimson veins, and each is deeply constricted about y 3 — y 4 from its apex. The 

 cells of this upper constricted part are covered with fine papillae, that probably aid 

 insects in their movements over the flowers. The petals in Sarracenia are modified 

 in shape and consistence at different levels, to adapt them to their role of aiding cross- 

 pollination. As shown in Figure 6 A each consists of a basal and a terminal segment. 

 The basal segment from its point of insertion gradually widens out into a triangulär 

 plate, it then becomes narrowed and has the margins slightly (S. psittacina) to deeply 

 (S. Drummondii) reflexed. This entire basal segment grows outward over the margin 

 of the style-umbrella as a firm expanse, and then widens into the terminal segment 

 that forms the large flaccid depending part of the petal. The external surface of this 

 segment has papillose epidermal cells, while over the inner surface a few honey glands 

 occur in some of the species. 



The stamens vary from \ — 00, and are inserted beneath the ovary. According 

 to Shreve they arise in Sarracenia as ten groups of primordia. The development of the 



Fig. 6. Sarracenia purpurea L. A Petal. B Vertical section of the flower, sepals and petals 

 cut away; fr ovary, gr style, n stigma. G Anther, from the outside. D Anther, from within. 

 E Transverse section of the ovary. F Seed. Vertical sect. of the seed. (Cop. from Engler- 



Prantl, Pflzfam. III. 2, p. 249, fig. 14 9.) 



four microsporangia in this genus, follows also the normal course for Dicotyledons, and 

 the microspores when ripe show a tube nucleus and a generative nucleus. In the youngest 

 flowers of Darlingtonia yet studied by the writer, the stamens were typically 1 5 and 

 formed a close circle round the still small pistil. The pollen grains are polyhedral in 

 end view, and ovoid in longitudinal view in all three genera. Relatively a large amount of 

 pollen is matured from one Sarracenia flower. This either falls, by its own weight, in 

 rieh showers into the umbrelloid style cavity, or often it is washed down and agglutinated 

 by drops of nectar that exude from the neetariferous ovarian wall. This relation of 

 the ovarian nectar to the pollen seems important, as giving the latter an adhesive 

 quality, that not only enables it to adhere to the bodies of insects, but equally to 

 the minute Stigmas that always seem to be dry in themselves. 



The pistil consists of 5 (Darlingtonia and Sarracenia) or of 3 (Heliamphora) 

 united carpels, that grow inward to form a 5 — 3-celled ovary v The numerous an- 

 atropous ovules in Sarracenia are arranged in five longitudinal rows along the thickened 



2* 



