AN D R E iE A . E h r h .
1. A. petropHla. E hrh.
2. — alpina. (D il l .) Sm.
3. — crassiiiervis. B ruch.
4. — Rothii. W eb. Mohr.
5. — nivalis. H ook.
MUSCl ACROCARPI.
Fruit terminating th e axis o f stem, or becoming apparently lateral
through being pushed aside b y a new shoot.
Scot. I . S C H I S T O C A R P I .
Capsule splitting v er tica lly into v a lv e s united at base and apex.
Fam. 1. ANDREiEACEiE.
Mosses w ith th e habit o f the genus Grimmia, a lways growing on
quartzose rocks, a tta ched b y a few radic les, and forming small, dense,
very fragile, fuscous, rufous or b la ck tufts. Stems rigid, slender,
dichotomous or fa sc icu la te . L e a v e s in 5 or 8 ranks, patent, secund
or fa lc a to - s e cu n d ; smooth or papillose, nerved or nerveless, ovate,
lanceolate or su b u late ; the c e lls minute, incrassate, rec tangular at
base, punctiform or angular above.
F ru it terminal, solitary, enclosed in the large perichietium up to
maturity, then exserted on th e elonga ted vaginula . Capsule ovate-
oblong, without operculum, sp litting into 4, or rarely 6— 8 valves,
united at apex, closed when moist, gaping w id ely and depressed when
dry ; the wall o f five c e ll-stra ta, w ithout a distinct sporangial membrane ;
columella cylindric, extending from base to apex. C a lyp tra campanulate,
c losely adhering to capsule, mitriform, torn irregularly. Spores
smooth. Male inflorescence gemmiform, terminal, or lateral b y arrest
of development.
The species of Andreaa were united by the early authors with ^unger-
mannia, but they agree with the true mosses in all points of structure, the
only aberrant character being the valvate dehiscence of the capsule, giving
them a superficial resemblance to that genus of Hepaticce, to which also they
slightly approximate in the form of their prothallium. Their true place
appears to be between the Sphagnacecs and frondose mosses, since they
present certain points of agreement with the former, in the capsule being at
first enclosed in a similar large saccate calyptra, and then elevated on an
elongated pseudopodium, and also in the prothallium partaking somewhat of
the lobate form seen in Sphagimm.
The plants entirely agree with the genus Grimmia in habit, mode of
growth, and structure of leaves, but they deviate so widely from it in the
fruit, that I prefer to follow Bridel in retaining them in a separate section.
My friend Lindberg places them as the lowest family of the acrocarpous
mosses, and next after the Gvimmiacecü.