Prev | Current Page 131 | Next

Darwin, Charles, 1809-1882

"The Different Forms of Flowers on Plants of the Same Species"


In the long-styled form of L. grandiflorum, the almost parallel or slightly
diverging anthers and stigmas project a little above the tube of the somewhat
concave flower; and they stand directly over the open space leading to the drops
of nectar. Consequently when insects visit the flowers of either form (for the
stamens in this species occupy the same position in both forms), they will get
their foreheads or proboscides well dusted with the coherent pollen. As soon as
they visit the flowers of the long-styled form they will necessarily leave
pollen on the proper surface of the elongated stigmas; and when they visit the
short-styled flowers, they will leave pollen on the upturned stigmatic surfaces.
Thus the stigmas of both forms will receive indifferently the pollen of both
forms; but we know that the pollen alone of the opposite form causes
fertilisation.
(Figure 3.5. Long-styled form of L. perenne var. Austriacum in its early
condition before the stigmas have rotated. The petals and calyx have been
removed on the near side. (3/3. I neglected to get drawings made from fresh
flowers of the two forms. But Mr. Fitch has made the above sketch of a long-
styled flower from dried specimens and from published engravings. His well-known
skill ensures accuracy in the proportional size of the parts.)
In the case of L.


Pages:
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143