392 Proceedings of the Royal Irish Academy. 



Peculiaeities op the Irish Hepatic Ploeas. 



It' is in the moist, "warm, sheltered glens of the high mountain 

 ranges near the coast that some of the rarest species flourish. A few 

 of them are alpine, as Scapania nimhosa and S. ornithopodioides, 

 Cesias, &c. The curious Clasmatocolea cuneifolia often descends, as do 

 other alpines or sub-alpines, to low elevations, washed down by 

 mountain torrents, so that in few instances can we recall species that 

 are exclusively alpine in habitat. About the Killarney basin the 

 luxuriance and beauty of some of the tropical species, such as Dumor- 

 tiera irrigua, are remarkable. This is accounted for by its sheltered 

 position, and the continual moist, genial atmosphere the plants enjoy 

 most months of the year. Similar luxuriance has been observed in 

 many of the glens in the Dingle peninsula, where 129 of the total 172 

 species of the Irish Hepatic flora are known to grow. 



It is remarkable that several of these plants have never 

 been found in fruit, and still continue to grow and increase, 

 as in the case of Plagiochila tridenticulata, the female plant of 

 which has not been seen. The same may be said of Clasmatocolea 

 cuneifolia] neither male nor female fruit has been found, and yet it 

 flourishes. Of Porella pinnata, sterile plants only are found in Ireland, 

 and, I believe, in Europe. Adelanthus decipiens furnishes another 

 example ; the male plant was once found many years ago at Killarney 

 by the late Dr. Camngton; but the female has never been seen on 

 Irish or British soil. The rare and beautiful Scapania ornithopo- 

 dioides, of which fertile specimens are unknown, luxuriates on 

 ^Brandon, in Kerry, and has been known to grow there for over one 

 tiundred years. 



Later research proves that Hepatics can propagate themselves not 

 only by spores, but by adventitious budding, gemmse being produced 

 on the leaf -margins, or almost on any part of the plant, stem and 

 perianth included. Dr. Spruce records an instance of Jungermania 

 juniperina {= Herherta adtmca) with branchlets growing out of the 

 leaves, which would in time become independent plants (see " Phyto- 

 logist," vol. ii., 1845, p. 85). My own investigations for a number of 

 years, on this subject of their asexual mode of propagation and dis- 

 persal, prove that 'they readily propagate by budding, and with more 

 certainty of growth, as the gemmae are often furnished with root-hairs 

 before they become detached from the parent plant. (See McArdle, 

 *' On Adventitious Branching in Liverworts," "Irish Naturalist," 

 voL iv., p. 81, plate 3, 1895). 



