Francis E. Lloyd — 42 — Carnivorous Plants 



leaf about 30 mm. long, the ends of the stipular margins were encoun- 

 tered about half the way up (ca. 15 mm.). This very gradual running 

 out of the stipular margins conveys the impression that the edge of 

 the wing is doubled throughout its length, and inasmuch as in the 

 adult leaf the edge of the wing in its upper reaches is, as a matter of 

 fact, also double, this doubhng seems continuous with that of the 

 stipular wings. We shall, however, see elsewhere that the one had 

 nothing to do with the other. In the juvenile leaf, however, the wing 

 is single above so that the end of the stipulation is clear. This in- 

 volves the study of transverse sections (5 — 4). 



At the same time it can be seen that the outgrowth to form the 

 wing had already started its growth beneath the stipular margins. 

 A study of the development of the leaf shows why this takes place. 



The adult leaves have been described a number of times, by Tor- 

 REY, Hooker, Macfarlane, Kurtz, Goebel and others, but despite 

 this, the precise morphological relations of the parts about the mouth 

 of the pitchers remain only vaguely comprehended. 



Adult leaves are produced both on short shoots, when they may 

 be quite small (1.5 cm. to 10 cm.) and on large vigorous rhizomes when 

 they attain a stature of a meter more or less. When seen in its native 

 habitat, growing thickly in large clumps, with its tall leaves standing 

 straight up, it affords a spectacular sight. The picture which is seen 

 reproduced {4 — i) was taken in an open glade on a steepish wet 

 hillside in the mountains east of Crescent City, Calif, in August 1938, 

 when many of the leaves were just approaching maturity. The seeds 

 were already fully ripe, since the flowers (4 — 2, 3) are produced in 

 early spring, before the leaves start to grow. 



The pitcher arises from a clasping base, the wings of which appear 

 concurrent with the ventral wing, the edge of which is doubled as in 

 Sarracenia ((5 — 15). The tube is tapering, widening upward. At 

 the top the tube spreads suddenly and at the same time is bent sharply 

 forward to form a dome, bringing the mouth into a horizontal posi- 

 tion underneath. From the front of the mouth a prominent forked 

 appendage, of ''swallow-tail" (Lemmon) or fishtail form, hangs 

 down with a forward curve. In the largest leaves the dome rnay be 

 10 cm. long, 6 broad and 5 deep, while in a very small, but still per- 

 fectly formed pitcher 1.5 cm. long, the dome measures only 2.5 mm. in 

 length. A feature peculiar to Darlingtonia is the twisting of the tube 

 either to the right or left so that the helmet-shaped dome is turned 

 about 180 degrees from the axis of the plant. All the leaves then 

 are turned outwardly, a position conceivably of advantage in attract- 

 ing prey. The small leaves often lie more or less prostrate and the 

 fishtail appendage lies on the surface of the ground forming a ramp 

 leading small creeping things to the opening {6 — 14). 



When the leaf is yet immature, but of full extent, the tissues of 

 the dome are still soft, and the two sides lie against one another. In 

 attaining their final shape the sides expand, the dome is inflated, and 

 then becomes indurated, so that, supported by the sclerotic cell walls 

 and other mechanical tissues, the dome attains a marked firmness, 

 like a hard hat. The wings of the appendage spread to form a plat- 

 form leading to the opening, its ventral surface secreting much nectar 



