44 THE AMERICAN MIDLAND NATURALIST 
also attain quite a considerable size. Concerning the shape 
of the leaf-segments, these are generally narrower than the 
type. This difference is evident even in young specimens 
(Figs. 2-3), which have not yet reached the flowering state. 
In mature leaves the relative size and outline of the segments 
are quite distinct from that of the typical plant. As a mat- 
ter of fact it seems characteristic of the variety “pusilla” 
that. the central leaf-segment is shorter and broader than the 
two lateral. Furthermore, the lateral segments often exhibit 
an outline approximately falcate. Among the numerous speci- 
mens which I examined, leaves in which the three segments 
were of uniform shape and size were rare. The leaf figured 
(Fig. 5 )may give some idea of the general size and outline 
of the leaf. of a mature specimen of the variety. The largest 
leaves are of course to be found in fruiting specimens. When 
two leaves are developed the basal is always larger than the 
superior. For instance in a fruiting specimen, collected on 
the second day of August the two leaves showed the size as 
follows: 
Basal leaf: central segment, length 16.5 cm. width 9.0 cm. 
Basal leaf: lateral segment, length. 22.0 em. width 7.0 cm. 
Superior leaf: central segment, length 14.0 cm. width 5.5 cm. 
Superior leaf: lateral segment, length 15:0 cm. width 5.4 cm. 
In a staminate specimen, collected on May 31st, the single 
leaf measured: 
Central segment length 9.5 cm. width 4.2 cm. 
Lateral segment length 12.0 cm..width 3.1 cm. . 
As compared with the typical plant the variety pusilla is 
thus readily distinguished by (1) its late appearance, late 
blooming and fruiting; (2) the relatively smaller size of in- 
florescence, spathe and spadix; (3) the uniform deep color of 
the spathe, except in chlorotic specimens; (4) the leaf-seg- 
ments being narrower, and the two lateral being generally 
longer and narrower than the central (Fig. 5); (5) the ap- . 
proximately falcate shape of the lateral segments; and finally 
(6) the habitat being either low woods, partially inundated 
during the winter, or sphagnum-bogs. : 
I have not, so far, found the typical plant and the variety 
growing together, and considering the nature of the sur- 
roundings, .I presume these to be the direct environal cause 
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