I could detect no difference in the size of the pollen-grain or
in the structure of the stigma in the plants which differed most in the above
respects; and all of them, when protected from the access of insects, yielded
plenty of seeds. Again, from statements made by Vaucher, and from a hasty
inspection, I thought at first that the allied Anchusa arvensis and Echium
vulgare were heterostyled, but soon saw my error. From information given me, I
examined dried flowers of another member of the Boragineae, Arnebia
hispidissima, collected from several sites, and though the corolla, together
with the included organs, differed much in length, there was no sign of
heterostylism.]
Polygonum fagopyrum (Polygonaceae).
(FIGURE 3.7. Polygonum fagopyrum. (From H. Muller.)
Upper figure, the long-styled form; lower figure, the short-styled.
Some of the anthers have dehisced, others have not.)
Hildebrand has shown that this plant, the common Buck-wheat, is heterostyled.
(3/13. 'Die Geschlechter-Vertheilung' etc. 1867 page 34.) In the long-styled
form (Figure 3.7), the three stigmas project considerably above the eight short
stamens, and stand on a level with the anthers of the eight long stamens in the
short-styled form; and so it is conversely with the stigmas and stamens of this
latter form. I could perceive no difference in the structure of the stigmas in
the two forms.
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