EvANS: REPORT ON THE HEPATICAE OF ALASKA 591 
inflorescence dioicous: 2 inflorescence borne on the stem or on a 
leading branch, often with one or two subfloral innovations; bracts 
similar to the leaves and intergrading into them; innermosc 
bracts about 1.5 mm. long and 1 mm. wide, the marginal teeth 
about twenty-five, usually longer than those on the leaves, an 
occasional tooth sometimes attaining a length of seven or eight 
cells; perianth narrowly obovate, about 2.7 mm.-long and 1 mm. 
wide, strongly compressed, the sharp keels destitute of wings, 
sharply and densely ciliate at the truncate mouth: < inflorescence 
and sporophyte not seen. (PLATE 21, FIGS. I-6.) 
This and the following species are closely allied but have no 
near relatives among the other species known from North America. 
Some of the East Indian species resemble them to a certain extent, 
and the same thing is true of various Andean species. The writer 
finds it impossible, however, to refer them to any described species 
and therefore proposes them as new, in spite of the fact that the 
species of Plagiochila are already so numerous and so incompletely 
understood. 
In P. alaskana the following characters are perhaps the most 
important from a diagnostic standpoint: the simple or sparingly 
branched stems; the intercalary branches: the postically secund 
and often deflexed leaves; the narrowly arched line of attachment, 
the antical base being remarkably long-decurrent; the dentate or 
ciliate-dentate leaf-margins; the group of elongated cells at the 
base of the leaves; the exalate perianths. These peculiarities 
would place the species in Schiffner’s section Denticulatae,* a 
well-marked group which Stephani unfortunately does not 
recognize. é 
Among the species of this group growing in tropical Asia 
mention may be made of two, P. renitens Nees,t of Java, Sumatra, 
and India, and P. trapezoidea Lindenb.,f of Java. In both of these 
Species the characters just enumerated for P. alaskana are more or 
less clearly exhibited. Both species, however, are considerably 
larger, the stems sometimes attaining a length of 10 cm. and the 
oe a Mile: of 2.5 mm. or more. The leaves, moreover, are 
* Die Hepaticae der Flora von Buitenzorg. Fl. Buitenzorg 4: 100. 
t Lindenberg, Monogr. Hepat. Gen. Plagiochilae 90. pl. 17, f. 1-6. tae Fassia 
mannia renitens Nees, Enum. Plant. Crypt. Javae 1: 76. 1830 
Ly cy tna: pl. 22, f. 1-18. 184 
