210 Evans: Notes on genus Herberta 



Most of the earlier writers not only failed to distinguish 

 H. Hutchinsiae from H. adtmca but considered the combined 

 species a mere variety or form of the Jamaican H. juniperina 

 (Sw.) Trevis. (Jungermannia juniperina Sw.). Hooker was appar- 

 ently the first to advance this idea. In the text accompany- 

 ing pi. 4 of his British Jungermanniae he recognized J. juniperina 

 as a member of the British flora and included /. admica under the 

 variety "/S," to which he did not even give a definite name. 

 "After a most careful examination of Mr. Dickson's /. adunca, 

 compared with others of /. juniperina, which I have received 

 from Dr. Swartz," he adds in a critical note, "I am unable to find 

 any characters which can induce me. to keep them separate." He 

 then calls attention to the larger size of the Jamaican plant and 

 to the greater readiness with which it regains its original appear- 

 ance when immersed in water but clearly regards these features 

 of but little moment. Weber* protested against Hooker's treat- 

 ment of /. adimca and maintained it as a valid species, in which 

 he was followed by both S. F. Gray and Dumortier. The majority 

 of contemporaneous writers, however, followed the example of 

 Hooker, and the Synopsis Hepaticarum, in 1845, went so far as 

 to cite Scottish specimens under Sendtnera juniperina /3, without 

 even mentioning /. admica as a synonym. When Gottsche, nearly 

 twenty years later, distinguished between his a Dicksoniana 

 and /3 Hutchinsiae, he pointed out in addition the most marked 

 differences between H. adunca and H. juniperina; and, since this 

 time, both species have been almost universally recognized. 



Among the characters of H. adunca which Gottsche emphasized 

 was the lack of teeth on the leaves and underleaves. He pointed 

 out the fact that young leaves sometimes showed five to eight 

 primordial papillae at the base, these structures representing the 

 rudiments of teeth, but of actual teeth he found no development. 

 Although this description will apply to the vast majority of leaves, 

 it will not apply to all. An occasional leaf will show one or perhaps 

 two teeth in the basal region. Such a tooth usually consists of a 

 single cell, serving as a stalk for a papilla, but it sometimes attains 

 a length of several cells and becomes more lobe-like in appearance. 

 The occurrence of these teeth, in view of their infrequency and 



* Hist. Muse. Hepat. Prodr. 54. 1815. 



