20 



J. M. Macfarlane. — Sarraceniaceae. 



recurved placental margins (Fig. 6 E). Eacli ovule undergoes typical angiospermic 

 development, up to the time of pollination. In Heliamphora the conical ovarian wall 

 (Fig. %D) is covered with bifurcated hairs and with honej glands, like those of the 

 pitcher exterior. In Sarracenia as above noted, the entire ovarian surface is covered 

 with multicellular tubercular crystalline swellings (Fig. 5F) that begin to exude nectar 

 as the flower opens. The excretion may go on more or less interruptedly, if pollination 

 is not effected, for 10 — 20 days, by which time the petals and stamens will have 

 fallen. But it may even exude for 5 — 8 days after the deciduous flower parts have 

 fallen. The style is a cylindrical pillar in its lower part, that is traversed centrally 

 by a canal, down which the pollen tubes pass. Higher up it expands greatly in umbrelloid 

 fashion to form a large cavity, which, from the inclined position of the flower, receives 

 the abundant pollen that falls from the stamens above (Fig 6B). Its outer surfaces 



may be more or less hair-covered, and abundantly 

 provided with stomata. The latter structural detail 

 is in keeping with the green persistent condition 

 shown in the fruiting state. The small projecting 

 stigmatic knobs (Fig. 6 Bn) bear abundant but 

 minute stigmatic hairs, and from the stigmas loose 

 conducting cells pass into the style veins. 



In Darlingtonia the turbinate ovary of the 

 pistil (Fig. 7 Ä) is closely covered with shallow cry- 

 stalline tubercles, that histologically resemble those 

 of Sarracenia. These exude a moderate amount 

 of nectar. The short style that Springs from the 

 centre of the depressed apex of the ovary ends 

 in 5 horizontal slightly grooved style arms, whose 

 sides and extremities are covered with elongated 

 mm tapered and overlapping stigmatic cells. The three 



P^ JF^Szk genera therefore of this group secrete floral nectar 



either by glands like those of the sepals and vegeta- 

 tive leaves (Heliamphora), or by special tubercular 

 ovarian glands. 



Torrey and De Candolle have drawn atten- 

 tion to the relation of the carpels to the stamens 

 and sepals. In Sarracenia the carpels are opposite 

 the sepals, and if as stated above the stamens 

 arise as ten primordia, such would be the normal 

 relation in the successive whorls. Faxon delineated 

 for Torrey the carpels of Darlingtonia as being 

 alternate with the sepals, and this would seem to be their true relation, for if the 

 typically \ 5 stamens arise as distinct primordia, such would be the normal succession. 

 Study of the floral embryology will alone settle the point satisfactorily. 



Detailed Information is still lacking as to the pollination of Heliamphora, but from 

 the floral structure this is probably effected in a simple manner by insects that are 

 attracted by the nectar of the sepals and ovarian wall. In Darlingtonia the flowers 

 seem to be proterandrous, and the pollen from the relatively short stamens is matured 

 as the flower opens. Attracted by the ovarian nectar, insects receive the pollen and 

 carry it to older blooms, in which the radial style arms are now fully divaricate and 

 ripe for its reception. Anthers examined in this later stage, at times show a few 

 starved or empty pollen shells, but few if any that are good. The pollination of 

 Sarracenia is the most complicated, and has been described by Hildebrand, Masters 

 and the writer. When the blooms begin to unfold, an odor is given off that varies 

 with the species. S. flava, S. Sledgei and S. minor exhale this most powerfully 

 toward evening, as might have been expected from the color of the flowers. The odor 



Fig. 7. Darlingtonia californica Torr. 

 A Flower, sepals and petals cut away, 

 twice magnif. B Transversc section of 

 the ovary. C Seed. D Vertical section 

 of the same. (Gop. from Engler-Prantl, 

 Pflzfam. III. 2, p. 252 fig. -152.) 



