Targionia hypophylla L.

Targionia hypophylla L. Sp. PI. 1136. 1753
Targionia Michelii Corda, in Opiz. Beitr. 649. 1829.
Targionia germanica Corda, in Opiz. Beitr. 649. 1829.
Targionia mexicana Lehm. & Lindenb.; Lehm Stirp. Pug. 4: 27. 1832.
Targionia capensis Hiiben. Hep. Germ. 17. 1834.
Targionia bifurca Nees & Mont.; Mont. Ann. Sci. Nat. H. 9: 113. 1838.
Targionia convoluta Lindenb. & Gottsche; G. L. N. Syn. Hep. 576. 1846.
Thallus usually with a narrow purple margin above and deep-purple below, plane or nearly so wlien moist but often with the margins more or less incurved when dry, mostly 1-2 cm. long and 2-5 mm. wide; ventral branches including apical innovations usually abundant; epidermal cells averaging about 30 X 15 ;Lt, the trigones often with convex sides; pores somewhat elevated, appearing as more or less conspicuous white dots, with a broad membrane around the opening, surrounded by about 6 radiating series of cells with 2 cells in each series; filaments in the air-chambers composed of spheroidal cells, the terminal cells in the vicinity of the pores larger than the others and usually colorless except at their bases; ventral tissue composed of cells with more or less pitted walls, scattered cells containing oil-bodies present and sometimes slime-cells; ventral scales large but scarcely reaching the margin of the thallus; appendage lanceolate, mostly 0.25-0.45 mm. long and 0.1-0.2 mm. wide, the margin entire to sparingly and irregularly spinose-dentate. Autoicous; antheridia borne in a small cluster at the tip of a short ventral branch; involucre several cells thick throughout and developing air-spaces without filaments in thebasal part, becoming deep blackish-purple with age and often iridescent, the margins entire or minutely toothed; spores brown, mostly 60-80 fi in diameter, indistinctly tetrahedral, covered over with a very fine and irregular reticulum, the meshes mostly 2-3 m wide, and in addition with a coarse and regular, although often incomplete reticulum, the meshes 16-20 m wide; elaters mostly 8-12 fx wide, usually with two dark spiral bands throughout the entire length.
Type locality: Europe (Italy, Spain and Turkey).
Distribution : British Columbia south to California and Arizona ; Mexico ; Salvador ; also in South America, Europe, Africa, Asia, and various islands of the Pacific; growing on shaded and usually
rocky banks.