AMBLYSTEGIACEAE. 315 
I have not been able to see the plant referred to by Brotherus 
(loe. cit.) as gathered by rae (No. 609) at Tyson’s Mill, Otago, 
possibly differing from S. Bel 
DreEPANOCLADUS (C. M. as Subseet. of Hypnum) Roth in Hedwig. 
XXXVI, eee p. 6 (1899). (Hypnum Seet. Har pidium 
] uct.) 
A genus of ee or aquatic mosses, which while small 
in point of species, is probably responsible for as large a number 
of individuals as almost any group of mosses, several of the species 
being very widely distributed, and nearly all being extremely plastic. 
(Paris has more than two pages of the varieties of H. fluwitans alone!) 
The arrangement of the forms of the northern hemisphere have given 
rise to much controversy. In New Zealand, however, fortunately 
for the student, they do not seem, with the exception of D. fluitans, 
particularly common or variable. 
ee Leaves distinctly plicate _..... DAES Sem A oe ae 1. uncinatus 
( beaves not or very faintiy pheaie 2 fan - 2 Si ea 
( Leaves Straight; habit of a very slender Fonti- 
3 fj Alar cells few, often not at all clearly defined 2. brachiatus 
( Alar cells numerous, clearly defined ..— .... fa —- 
"Seasaihie sub-deltoid at base, rather’ shortly 
Pa, subulate ReSOh a a nT Rie ee Ne ceee Qi ee tape y 3. aduncus 
{leet base narrow, oblong, acumen long g and 
tapering bao 
vee 
oe . fluitans 
1. Drepanocladus uncinatus (Hedw.) Warnst. in Beih. z. Bot. 
Centralbl. xiii, 417 (1903). 
Syn. Hypnum uncinatum Hedw. Deser. iv, 65; Fl. N.Z. ii, 
107; Handb. N.Z Fie p. 472. MM ypnum aduncum fhe 
Sp. PL, non Hedw 
The typical aa is readily erm by its strongly faleate, deeply 
nlicate leaves, with rather numerous but quite small alar cells; the 
autoicous inflorescence, and the extremely long, plicate pevihaeta 
leaves. A small form, perhaps var. plumulosus (Bry. eur.) occur: 
im very Gea tufts, with v very small, searcely hae leay 
this may be difficult to recognize; the absence of enlarged ae Leis 
will however distinguish it from all but D. br. achiatus, whieh is much 
taller sgt of a quite different habit 
t might easily be confused with Brach ythecium paradoxum, but 
the serrulate, less gradually tapering leaf acumen of that species, 
with the more gradually widened base and alar cells, wiil distinguish 
it. In fruit they are quite distinct; the perichaetia a and capsule in 
a. pipenies being much narrower and longer, and the seta smooth. 
Tt appears to be rare in New Zealand. In the northern hemisphere 
and eons in the aretic regions it is one of the most abundant 
mosses. 
