Chapter II — 29— Sarracenia 



the tube is not developed. The leaf then consists of a cylindrical 

 stalk with a wide ventral wing. At the apex there is more or less 

 of a depression. Such leaves are photosynthetic only, and have been 

 compared by Goebel to the unifacial leaf of Iris. These leaves de- 

 velop later in the growing season (Goebel). 



Having favorable material at Munich, I arranged the upper part 

 of a leaf under a bell jar and put a blue bottle fly inside. The leaf 

 stood vertically in shallow water in a vial. The fly was soon attracted 

 by the nectar secreted by the glands of the external surface and gradu- 

 ally worked his way by an erratic path to the rim. Mounting this 

 he began to sip the nectar, either on the under surface of the lid as 

 far as he could reach without letting go his hold with his hind legs 

 on the edge of the lid, or of the rim. Swinging about he explored 

 the surface inside the rim, always hanging on by his hind legs; and 

 it was evident that he was aware of the precarious foothold, for he was 

 loth to free his hind foot or feet. But on getting what seemed to be 

 a foothold and reaching as far as possible for the nectar, he would 

 let go and then invariably fall plump into the abyss. A bit of the 

 tube was cut away above the water level so that he could escape, 

 and in consequence he performed for me again and again. His actions 

 were repeated a dozen times without failure of being trapped. If 

 he ventured on the under side of the lid, as he sometimes did, he 

 could remain there as long as he grasped the edge with one foot, seiz- 

 ing the hairs with the other; but the moment he let go of the edge, 

 down he fell into the tube. There is therefore no question but that 

 the surface of zones i and 2 is one which gives no foothold to such 

 flies and, to infer from the variety of prey found in the pitchers, to 

 most other insects as well. 



Sarracenia flava. — This species resembles S. Drummondii in many 

 respects, but is stouter and coarser, and its prevailing color is greenish- 

 yellow, with the latter color quite dominant. The tube tapers gradu- 

 ally from the mouth down, being widest at this point. The lid is 

 more erect and has a narrower and stouter neck, and is backwardly 

 recurved at the edges. The apex, instead of being emarginate as in 

 some species, is acute (7 — 7). A leaf 24 cm. long, examined at Munich, 

 shows zonation as follows. 



Zone I is the under surface of the lid and carries many short, 

 stout, downwardly pointed hairs and many nectar glands. The lower 

 limit of this zone is very irregular, the hairiness following the promi- 

 nent veins, the spaces between being smooth and glaucous and con- 

 tinuous with zone 2, which is lined with an epidermis of imbricated 

 pointed cells with many glands scattered over the surface. This zone 

 extends about 2 cm. downwards, and includes most of the neck, the 

 nectar roll and a narrow zone below it, as in 5. minor. This is deep 

 yellow, glaucous and the imbricated cells of the epidermis are short 

 pointed. There are glands present in great numbers, and, quite as in 

 other species described, this is a dominant place of lure. The lower 

 limit of this zone is not defined but fades into zone 3 (8 cm. deep), 

 in which the imbricated cells have longer retrorse points. The num- 

 ber of glands is reduced so that in the lower regions there are none 

 to be found. The whole area is glaucous. The lower limit of zone 3 



