DICRANACEAE. 43 
As mentioned above, the leaves of Distichium capillaceum, Ditrichum 
elongatum, D. strictum and D. punctulatum very closely resemble one another, 
and great care is needed to aes the species, especially in the absence of 
fruit. The sae sage sr in Districh, capillaceum is paroicous ; in Ditrichum 
strictum and D. elongatum, autoicous ; in D. punctulatum it appears to be 
truly dioicous, as described by Mitten; Mr. Gray’s plants show numerous 
stems, bearing terminal male flowers, about ? in. or | in. in dapat and cer- 
tainly entirely separate, not connected with the fertile stem 
Distichium capillaceum is known by its truly distichous aN in which 
ae subula is usually Sabian: ap only slightly denticulate towards apex. 
he capsule is very small, and varies little in form ; it is elliptical, usually 
rato the lid) about 1°5 mm her but rangin from 1 mm. to 2 mm., not 
perceptibly narrowed to the mouth, erect and symmetrical or very slightly 
gibbous. The lid offers the best means of distinction from the similar 
i ieaibs of Ditrichum ; this is very short, scarcely more than one-fourth the 
length of the capsule, conical or very shortly and not acutely rostellate, the 
short beak being often curved and somewhat eccentrically placed. e 
Liha eee are short, inserted far below the capsule-mouth, split into 
two often unequal halves which are more or less app vertically or 
Sittuehy atridlats but otherwise quite smooth. Spores 
Ditrichum elongatum when in fruit is readily known, as described under 
that species. The leaves are in no way Sy rahe and are usually more 
closely set than in D. punctulatum, never, I think, so distant as is usual in 
that acces ; otherwise I am unable to detect any difference in the leaf- 
structure. The colour appears to be usually a dull or yellowish green. 
D. strictum has the leaves closely set also, but they are much more rigid 
than in D. elongatum, and usually very dark in colour, sometimes almost 
black. The leaf-base tapers much more gradually into the subula than in 
D. punctulatum and D. elongatum, and does not show the abrupt shoulder of 
those — and the cells of the upper part of the sheathing base, though 
short, are rarely isodiametrical, usually elongate rhomboid, and more or less 
clear and pela not forming the group of dense, obscure cells of the 
it is flattened out so as even to appear slightly spathulate ; this wide obtuse 
apex being often markedly though not sharply denticulate 
The capsule in D. strictum is small, 1mm. to 1:25 mm. long, rarely 
15mm. (without lid), on a a seta. It is pachydermatous, widely 
elliptical, with a narrowed m the lid in the only operculate.capsule I 
have found in Hooker’s ipa cea is longly and finely subulate, the straight 
erect beak being about as long as the capsule itself. specimen of 
* Leptotrichum australe Mitt., Tasmania, Archer” in paces Kew., which 
Mitten by implication retains under D. strictum (not D. punct latum), varies 
somewhat in the form of leaf-base, but has the tapering sbeaite: and the 
upper cells of D. strictum; this shows a decidedly longer and narrower 
pig than the type of D. strictum, having capsules fully 2 mm. long, on 
stout s 
D. pili m is a much more slender, flexuose plant than D. strictum, 
pale green above when fresh, with stems more than an inch in height. The 
leaves are normally and almost constantly distant, so that the greater part 
of the sheathing base is exposed, and this gives a slender, ers marked and 
