196 BOTANICAL GAZETTE. [SEPTEMBER 
of Europe. The upper and lower surfaces of the lower leaves are 
not wrinkled as we have seen in O. Lamarckiana, and are less hairy. 
The buds are much smaller than those of O. Lamarckiana, aver- 
aging 1.5 cm. long, 6 mm. wide at the base, and 1.5—2 mm. wide at the 
top. Besides being smaller, they are different in form from those 
of O. Lamarckiana. One side of the bud is rather straight, and the 
other more or less gibbous. Comparing this with the American species, 
as shown by Britron and Brown’s figure,° there is another dif- 
ference, for in the American forms the buds are larger and more 
pointed, especially at the apex, than in the Holland type. The hairs 
on the buds are only about half the size of those of O. Lamarckiana. 
The flowers are much smaller than those of O. Lamarckiana and 
are bright yellow. Each flower stands in the angle of a nearly sessile 
bract on the rather narrow spike. The calyx tube in this form 
is 1.5-2 times the length of the reflexed sepals. The density of 
the pubescence on the sepals is about the same as for O. Lamarckiana. 
The irregularity shown in the epidermal cell walls of the sepals " 
much less in O. biennis than in O. Lamarckiana, and especially is 
this true of the inner epidermal cell walls, which are only wavy, and 
in which the thickenings are almost completely absent.. The cells 
of the outer epidermis are also decidedly smaller and have but 
few thickened places. 
The four petals are broad, slightly unequally lobed, somewhat 
indented at the apex, and larger than the sepals. The cells both of 
the inner and outer epidermis are smaller, more regular in form, and 
are, especially those of the inner epidermis, almost devoid of the 
angular thickenings shown by O. Lamarckiana. 
One of the chief differences in the flowers of O. Lamarckiana and 
O. biennis is that in the latter the stamens are of the same height 
as the stigma, and the anthers are in contact with the stigmé 
in the bud. Therefore self-pollination nearly always results, whereas 
in O. Lamarckiana it was generally brought about by insects. The 
four anther cells do not always open simultaneously, but some 
may have partly opened and shed their pollen before the opening 
process in the other cells has begun. The ovary is four-celled and 
pubescent. : 
6 BRITTON AND Brown, of. cit. 2:486, jig. 2579. 
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