He has seen in St. Catharina, in Brazil, a large field of
young sugar-cane, many acres in extent, covered with the red blossoms of one
form alone, and these did not produce a single seed. His own land is covered
with the short-styled form of a white-flowered trimorphic species, and this is
equally sterile; but when the three forms were planted near together in his
garden they seeded freely. With two other trimorphic species he finds that
isolated plants are always sterile.
Fritz Muller formerly believed that a species of Oxalis, which is so abundant in
St. Catharina that it borders the roads for miles, was dimorphic instead of
trimorphic. Although the pistils and stamens vary greatly in length, as was
evident in some specimens sent to me, yet the plants can be divided into two
sets, according to the lengths of these organs. A large proportion of the
anthers are of a white colour and quite destitute of pollen; others which are
pale yellow contain many bad with some good grains; and others again which are
bright yellow have apparently sound pollen; but he has never succeeded in
finding any fruit on this species. The stamens in some of the flowers are
partially converted into petals. Fritz Muller after reading my description,
hereafter to be given, of the illegitimate offspring of various heterostyled
species, suspects that these plants of Oxalis may be the variable and sterile
offspring of a single form of some trimorphic species, perhaps accidentally
introduced into the district, which has since been propagated asexually.
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