Ртилопгм 145 
smaller and subinflexed, the segment-margins very entire, repand, 
or here and there again incised or sometimes bearing a few (2 or 
3 on a side) long and rather rigid cilia: underleaves usually a little 
broader than the stem, deeply 2- or 3-parted, the segments in- 
ciso-ciliate ; leaf-cells 40-45 и, hexagonal- or pentagonal-rotund, 
the walls strongly thickened at the angles, cuticle smooth: 
dioicous: 4 plants commonly more slender, androecium cauline 
or rameal, antheridia ovoid or ellipsoidal, single or in pairs, the 
stalks finally much shorter than their long diameter: 9 branch 
short, bearing about 2—4 pairs of leaves inclusive of bracts : bracts 
one or two pairs, a little larger than the leaves and more inciso- 
ciliate ; bracteole similar, rarely connate with bracts on one or both 
sides ; perianth cylindrical-obovoid to subfusiform-oblong from an 
obconic base, slightly narrowed at the ciliate subplicate mouth: 
spores brown, 21-30 и; elaters 120-225 их 7-10 и, 2- (rarely 3-) 
spiral, contorted, subobtuse. 
Found in California only by its first collector, Dr. Bolander. 
The plants from which the original description was drawn were 
picked out from specimens of Hypnum circinale in Sulliv. & Lesq. 
Мизс. Bor.-Am. Exsicc., No. 474, ed. 2; these are now preserved 
in herb. Pearson. Duplicates of this original material may often 
be found in connection with no. 474 of the Exsicc. cited. Habitat 
and locality were given as “ай corticem arborum in sylvis Cali- 
forniae montanae.” The specimens doubtless came from Hum- 
boldt or Mendocino counties, and the plant is to be looked for on 
the bark of living trees and fallen trunks of Seguoia sempervirens 
and of other conifers in the northern coast region. The species 
extends northward to British Columbia (Macoun) and to Idaho 
(Leiberg). Some of the northern specimens make a nearer ap- 
proach to Ptilidium ciliare, which also occurs іп the same region, but 
are always very distinct in the less branched stem, the more rigid 
leaves, with much more pronouncedly filiform-attenuate segments 
and longer, more rigid, and always much less numerous cilia. 
PLATE 105. PTILIDIUM CALIFORNICUM. 
Plants, natural size. 
Portion of stem, with branch, X 12. 
Cauline leaf, viewed from above, X 23. 
Cauline leaf, viewed from below, X 23. 
A 3-cleft cauline leaf, viewed from below, X 23. 
A typical apex of leaf-segment, X 41. 
Cauline leaf, ventral view, X 2 
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