PORELLA 161 
Ашота Raddi, Atti Soc. Ital. Sci. Mod. 18 :--(8): 1818. 
Mem. Mat. е Fis. Soc. Ital. Sci. Mod. 18: 19: 1820. 
-Cavendishia S. Е. Gray, Nat. Arr. Brit. Pl. І: 689. 1821. 
Madotheca Dumort. Comm. Bot. 111. 1822. Nees, Natur- 
gesch. Eur. Leberm. 3: 157. 1838. 
Plants large, dark-green to yellowish-brown, mostly somewhat 
regularly bi- or tri-pinnate, rarely subsimple; root-hairs in tufts at 
the base of the underleaves, usually sparingly developed. Leaves 
very deeply 2-parted; the dorsal lobes large, incubous, obliquely 
orbicular-ovate to oblong, entire, repand or somewhat dentate ; 
ventral lobes much smaller than the dorsal, sometimes nearly dis- 
crete, ovate, lingulate, oblong, linear, or lanceolate, nearly parallel 
with the stem, entire or toothed, margins plane or revolute. Un- 
derleaves large, somewhat similar in form to the ventral lobes but 
mouth, from a more or less obconical base, much longer than the 
bracts, two-lipped after elevation of the capsule or sometimes irreg- 
ularly torn, mouth ciliate, dentate, or subentire. О bracts usually 
a single pair with a single bracteole in addition to the underleaf at 
the base of the branch, the latter underleaf united with the sub- 
tending cauline leaf and functioning as its ventral lobe, or free, 
leaving the cauline leaf unlobed. Capsule spherical to ovoid-oblong, 
on a short seta, yellowish-brown, opening, usually not quite to the 
base, by four often irregularly split valves ; cell-walls of the valves 
mostly with irregular nodulose thickenings. Elaters commonly 2- 
(1-3-) spiral ; spores several times broader, more or less echinulate. 
Key to the Species. 
branching, short, tumid ; underleaves cau- 
liate. i 
Stems subsimple or somewhat fasciculately 
th P. Bolanderi. 
date-lacinulate at Базе; perianth-mouth ciliate 
Stems more or less regularly 1—3-pinnate. 
Usually shining. 
Ventral lobes more or less spurred outwardly at base, mostly linguiform or 
ovate-oblong, margins plane or lightly recurved. 3. P. Кой. 
Ventral lobes regularly rounded outwardly at base, ovate, margin recurved. 
P. navicularis. 
4. 
Usually dull ; rather flaccid, dorsal lobes subimbricate, ventral lobes long-decurrent, 
d 2. P. rivularis. 
underleaves distant. 
