The pistil is very
short, and is surmounted by a bilobed stigma. As the ovary grows the two anthers
together with the shrivelled corolla, all attached by the dried pollen-tubes to
the stigma, are torn off and carried upwards in the shape of a little cap. The
perfect flowers generally appear before the cleistogamic, but sometimes
simultaneously with them. During one season a large number of plants produced no
perfect flowers. It has been asserted that the latter never yield capsules; but
this is a mistake, as they do so even when insects are excluded. Fifteen
capsules from cleistogamic flowers on plants growing under favourable conditions
contained on an average 64.2 seeds, with a maximum of 87; whilst 20 capsules
from plants growing much crowded yielded an average of only 48. Sixteen capsules
from perfect flowers artificially crossed with pollen from another plant
contained on an average 93 seeds, with a maximum of 137. Thirteen capsules from
self-fertilised perfect flowers gave an average of 62 seeds, with a maximum of
135. Therefore the capsules from the cleistogamic flowers contained fewer seeds
than those from perfect flowers when cross-fertilised, and slightly more than
those from perfect flowers self-fertilised.
Dr. Kuhn believes that the Abyssinian V. sessiflora does not differ specifically
from the foregoing species.
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