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Show 298 GYNO-DICEOIOUS PLANTS. CHAP. VII. have examined many plants, but have never found one that was really hermaphrodite. I mention this genus because the stamens in the female flowers, al. though quite destitute of pollen, are but slightly and sometimes not at all shorter than the perfect stamens in the male flowers. In the latter the ovary is small and the pistil is almost aborted. The filaments of the perfect stamens adhere for a gr@ater length to the peta~s than in the female flowers. The corolla of the latter is rather s1naller than that of tho male. The male trees produce a greater number of flowers , than the females. Asa Gray informs rn.e that I. opacct, which represents in the United States our cmnmon holly, appears (judging from dried flowers) to be in a similar state ; and so it is, according to V aucher, with several other but not with all the species of the genus. Gyno-dia3cious Plants. The plants hitherto described either show a tendency to become dirncious, or apparently have become so within a recent period. But the species now to be considered consist of hermaphrodites and females without males, and rarely show any tendency to be dirncious, as far as can be judged frmn their present condition and from the absence of species having separated sexes within the same groups. Species belonging to the present class, which I have called gyno-dirncious,- are found in various widely distinct families; but are much more com1non in the Labiatoo (as 4as long been noticed by botanists) than in any other group. Such cases have been noticed by myself in Thymus serpyllum and vulgaris, Satureia hortensis, Origanum vulgare, and Mentha hirsuta ; and by others in Nepeta glechoma, Mentha vulgaris and CHAP. VII. G YNO-DICEOIOUS PLANTS. 299 aquatica, and Prunella vulgaris . . In these tw? latt~r species the female form, according to H. Muller}' IS infrequent. To these must be added Dracocephalum Moldavicum, Melissa o.fficinalis and clinipodium, and Hyssopus officinal is.* In the two last-narned plants the female fonn likewise appears to be rare, for I raised 1nany seedlings of both, and all were hermaphrodites. It has already been remarked in the Introduction that andro-dirncious species, as they rna y be called, or those which consist of hennaphroclites and males, are extreme! y rare, or hardly exist. Thymus serpyllum.-The hennaphrodite plants present nothing particular in the state of their reproductive organs ; and so it is in all the following cases. The females of the present species produce rather fewer flowers and have somewhat smaller corollas thp,n the hermaphrodites; so that near Torquay, where this plant abounds, I could, after a little practice, distinguish the two forms whilst walking quickly past them. According to V aucher, the smaller size of the corolla is common to the females of most or all of the abovementioned Labiatoo. The pistil of the female, though somewhat variable in length, is generally shorter, with the margins of the stigma broader and formed of more lax tissue, than that of the hermaphrodite. The stamens in the female vary excessively in length ; they are generally enclosed within the tube of the * H. MUller, 'Die Befruchtung der Blumen,' 1873 · and' Nature' 187B, p. 161. Va~cher, 'Plant;s d'Europe,' tom. iii. p. 611. For DracoceplJalum, Schimper, as quoted by Braun, 'Annals and M~~· of Nat. Hi st.' 2nd series, vol. xvm. ~856, p. 380. Lecoq, 'Geographie Bot. de l'Em·ope,' tom. viii. pp. 33, 38, 44, &c. Both Vaucher and.Lccoq were mistaken in thinking that several of the plants named in the text are dicecious. They appear to have assumed that the hermaphrodite form was a male; perhaps they were deceived by the pistil not becoming fully developed and of proper length until some time after the anthers have dehisced. |