A. W. Evans — Hawaiian Uepaticce of the Tribe Jicbuloidece. 389 



The tribe Jubuloideae, as defined by ScliiflEner,* is the equivalent of 

 the subtribe Jubulese of the Synopsis Hepaticarumf and of the tribe 

 Jubiilea? of Spruce. J It is without doubt the most natural assem- 

 blage of forms among the leafy Hepaticse ; it is in fact so natui'al 

 that Spruce did not hesitate to place it in contrast to his tribe 

 Jungermanniere, which included all the remaining acrogjnious Jun- 

 germanniacese and the anacr'ogynous Jungermanniaceae or Metzgeri- 

 acefe§ as well. Schiffner, on the other hand, looks upon the group as 

 one of the minor divisions under the acrogynous Jungernianniaceae, 

 equal in systematic value to the Ptilidioidese, the Scapanioideae, or 

 any of the other five tribes which he recognizes. The morphological 

 papers of Leitgeb|| would, of course, prevent a wide acceptance of 

 Spruce's view, and the disposition made by Schiffner is more in accord- 

 ance with the views of most recent hepaticologists and apparently 

 with the facts. A reason for the unusual division advocated by 

 Spruce is perhaps to be found in the extraordinary development of 

 the Jubuloideje in the tropics. Among the HepaticfB of equatorial 

 South America, to whose collection and study Spruce devoted many 

 years of his life, more than half of the species which he found 

 belonged to this group ; in the Hawaiian Islands, onlj- about a 

 quarter of the known species are Jubuloideai, but it is probable that 

 the higher proportion will be reached both here and in other tropical 

 countries, when their hepatic floras shall have been more thoroughly 

 investigated. 



Although so natural for a hepatic group, the characters of the 

 Jubuloideae, particularly those drawn from the gametophyte, are 

 somewhat difficult to define. This is partly because the sexual plant 

 exhibits considerable variation within the group, and partly because 

 several of its most striking and constant peculiarities recur in other 

 genera, sometimes widely removed from the Jubuloideae. In the 

 first place the gametophyte is very variable in size ; from the smaller 

 species of Cololejeunea, which are often only a few millimeters long, 

 we may pass by all gradations to the larger Frullanice, some of 

 which form drooping tufts a half meter in length. The more essen- 

 tial characters drawn from the vegetative organs are likewise just as 

 variable, although they show certain peculiarities which are fairly 



* Engler & Prantl, Natiirl. Pflanzeufam. 1% 116. 1893. 



t L- c. 283. 1845. 



X Hep. Amaz. et And. in Trans. & Proc. Bot. Soc. Edin. xv, 1. 1885. 



§ Underwood, Bot. Gazette, xix, 356. 1894. 



II Untersuch. iiber die Lebermoose, 1874-1881. 



