58 MARCHANTIACEAE 
stratum thin, the uppermost cells in the air-chambers with a 
conical or long-cylindrical colorless rostrum; costa clothed with 
closely imbricate scales, those at the apex often with a violet 
orbicular or reniform apical expansion, marginal scales absent. 
Gemmae-cups wanting. Androecium disciform, strongly papillate, 
sessile in a depression bounded by a somewhat scarious-mem- 
branous elevation of the dorsal layers of the thallus, termi- 
nating a short branch, this becoming apparently lateral by the 
continued growth of the othér fork. © receptacle obtusely con- 
ical, indistinctly or not at all lobed, long-stalked, surrounded when 
still sessile by a slightly elevated membranous sheath; peduncle 
with a single root-hair furrow, its dorsal (posterior) surface desti- 
tute of assimilative tissue. Involucres 4—11, tubular, confluent, 
constituting almost the whole of the matured receptacle, each 
surrounding a single sporogonium. Pseudoperianth wanting. Cap- 
sule oblong-pyriform, on a thick pedicel mostly a little more than 
one half as long, dehiscing by cleavage about to the middle into 
4-8 recurved irregular valves, its final exsertion usually accom- 
panied by the detachment of the pedicel from the receptacle, cap- 
sule-wall of mainly a single layer of thick cells with annular 
and spiral thickenings ; spores large, papillate, multicellular at time 
of dehiscence; elaters rather short and thick, 2—4-spiral. 
I. CONOCEPHALUM сохісом (L.) Dumort. [as Conocephalus] Comm. 
Bot. 115. 1822. Underw. Bot. Gaz. 20: 67. 1805. 
Marchantia conica L. Sp. PL ТГ, 71757, 
Fegatella сопіса Corda; Opiz, Beitr. 1: 649. 1829." 
Thallus oblong or linear, 5-25 cm. x .75-1.5 cm.; colorless 
stratum in region of the costa of 20-2 5 layers of small thick- 
angled cells, enclosing 3-5 large longitudinal (finally empty) muci- 
lage canals and passing abruptly at the sides into 7—4 layers of 
larger cells, becoming bi- (rarely uni-) stratose at the extreme | 
е Mox ek peduncle 3-6 cm. high, naked: spores d 
hende — За Ms eaters 200-270 xi 9-30 Ја ойс MM 
In moist deeply shaded places, especially on stones and rocks 
beside streams. 
Felton, Santa Cruz Co. (Underwood); on stones in stream-bed 
neus Lake Pilarcitos, San Mateo Co.; on moist ground in woods, 
"Big River Boom," near Mendocino ; and on shaded dripping 
rocks néar Eureka. Not common in California ; first collected | 
by Professor Underwood in 1888. 1 
* See footnote under Ricciocarpu’, р. 33. Ee 
