298 



DICECIOUS AND 



Chap. VII. 



informs me that I. opaca, which represents in the United 

 States our common holly, appears (judging from dried 

 flowers) to be in a similar state; and so it is, accord- 

 ing to Vaucher, with several other but not with all the 

 species of the genus. 



Gyno-dicecious Plants. 



The plants hitherto described either show a tendency 

 to become dioecious, or apparently have become so 



to be 



within a recent period, 

 considered consist of 



and 



But the species now 

 hermaphrodites and females 

 without males, and rarely show any tendency to 

 be dioecious, as far as can be judged from 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-dicecious, are found in various widely 

 distinct families; but are much more common in the 

 Labiatae (as has long been noticed by botanists) than 

 in any other group. Such cases have been noticed by 

 myself in Thymus serpyllum and vulgaris, Satureia 

 horlensis, Origanum vulgare, and Mentha hirsuta; and 

 by others in Nepeta glechoma, Mentha vulgaris and 

 aquatica, and Prunella vulgaris. In these two latter 

 species the female form, according to H. Miiller, is in- 

 frequent. To these must be added Dracocephalum 

 Moldavicum, Melissa officinalis and clinipodium, and 

 Hyssopus officinalis* In the two last-named plants the 



* H. Miiller, ' Die Befruchtung 

 derBlumen/ 1873; and 'Nature/ 

 1873, p. 161. Vaucher, ' Plantes 

 d' Europe/ torn. iii. p. 611. For 

 Dracocephalum, Schimper, as 

 quoted by Braun, 'Annals and 

 Mag. of Nat. Hist.' -2nd series, vol. 

 xviii. 1856, p. 380. Lecoq, * Geo- 

 graphic Bot. del' Europe/ tom.viii. 

 pp. 33, 38, 44, &c. Both Vaucher 



and Lecoq were mistaken in think- 

 ing that several of the plants 

 named in the text are dioecious. 

 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. 



