298 GYNO-DIOECIOUS PLANTS. Chap. VU. 



have examined many plants, but have never foimd 

 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 greater length to the 

 petals than in the female flowers. The corolla of 

 the latter is rather smaller than that of the male. 

 The male trees produce a greater number of flowers 

 than the females. Asa Gray 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, according to Vaucher, with 

 several other but not with all the species of the genus, 



Gyno-dioeeious Plants. 



The plants hitherto described either show a tendency 

 to become dioecious, 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 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-dioecious, are found in various widely 

 distinct families ; but are much more common in the 

 LabiatBB (as has long been noticed by botanists) than 

 in any other group. Such cases have been noticed 

 by myself in Thymus serpyllum and vulgaris, Satwrda 

 hortensis, Origanum vulgare, and Mentha hirsuta ; and 

 by others in Nepeta ' glechoma, Mentha vulgaris and 



