Feb. 1891.] BOTANICAL SOCIETY OF EDINBURGH, 61 



locality) being of opinion that it is only a very marked 

 variety of E. Tetralix. I cannot, however, concur in that 

 idea, as 1 noticed no intermediate states, although the latter 

 was growing in the greatest luxuriance within a few yards 

 of E. Mackayiana." In Hooker and Arnott's Flora (6th 

 edition, 1850) the following occurs : — " This, which is some- 

 times called E. Mackaiana, was first found in Ireland by Mr 

 Wm.Maccalla and Mr Ogilby,and distinguished by DrMackay, 

 and in the same year it was discovered on the Sierra del Perel, 

 in Asturia, by M. Durien. The broad, almost exactly ovate, 

 leaves, with a great proportion of nearly white surface 

 beneath, would seem, at first sight, to distinguish this speci- 

 fically from the preceding ; to which it may be added, 

 according to Mr Babington, that the upper surface of the 

 leaves and their midrib are always glabrous, while these 

 parts are downy in E. Tetralix. Perhaps, however, it may 

 prove, by cultivation, to be only a more glabrous form, with 

 larger foHage." 



Moore and More * regard it as probably a hybrid. Sir J. 

 Hooker ranks it as a sub-sp. of Tetralix, while Focket says, 

 "This plant is evidently a hybrid of E. Tetralix; the other 

 parent is probably E. ciliaris (or E. mediterranea or E. 

 cincrea.) 



From my comparison of plant hybrids, I may safely say 

 that if this be a hybrid it will be intermediate, microscopi- 

 cally, between its parents. That one of these is E. Tetralix 

 could not be doubted. That the other parent cannot be 

 E. cinerca or E. mediterranea, the structure of the leaf alone 

 would make certain, even though we took no note of other 

 and more divergent peculiarities. 



As indicated by Babington, E. ciliaris considerably re- 

 sembles it in the naked eye leaf-appearance, but, like the 

 hybrid E. Watsoni of similar parentage, we should expect 

 a unilateral, racemose infloresence, an irregular, instead of, as 

 in our specimen, a regular corolla, reduced anther- tails, &c. ; 

 but the microscopic structure completely confirms the idea 

 that these are not related, for, if we selected the leaf alone 

 in E. ciliaris, we find that the glandular cilia are arranged in 

 two rows on each edge of the quite flat leaf, not in a 



* Cybele Hibernica, 1866. 



t Die Pfianzen-Mischlinge, 1881. 



