60 MARCHANTIACEAE 
I. LUNULARIA cruciata (L.) Dumort. Comm. Bot. 116. 1822. 
Marchantia cruciata L. Sp. Pl. 1137. 1753. 
Thallus 1-5 cm. x .5-1 cm., colorless layer about 20 cells 
thick along the axis, becoming gradually thinner to the unistratose 
margin : peduncle 1.5-3 cm. high: spores 15-18 м; elaters 300- 
6504 long, 5—6 и broad in the middle. 
In and about greenhouses. Oakland, San José, and San 
Francisco (Underwood, 1888); Berkeley and San Francisco 
(Howe); also in the Golden Gate Park, San Francisco, at con- 
siderable distance from any greenhouse; Pasadena (fide Mc- 
Clatchie). Introduced from Europe. Only a sterile gemmiferous 
condition is known to occur in America, but the plant is easily rec- 
ognizable by the crescentic, entire-margined gemmae-cups, which 
are almost always present. Our diagnosis has been completed 
from European material and from the descriptions of authors. 
10. MARCHANTIA L. эр. LII 1754 
Ex March. 77. Act. Ac. Paris. 290; 1713: 
Thallus large, usually several times dichotomous, with a broad 
effuse costa, the root-hairs abundant, areolae mostly rhombic, 
Nomenclator Botanicus. 
T This, in effect, is asserted of the genus Marchantia by Stephani ( Bot Gaz. 17: 
60 1892. Bull. Herb. Boiss. 7: 384. 1899). Most of the numerous species of M 
chantia are exotic and we are unable to assert from any personal investigations that this 
character belongs to all. It certainly holds good for 77. polymorpha. 
