40 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 11 



triciiocoleaceae Nakai [A list of professor Xakai's papers . . . science] 200. 



1943. 



Ptilidiaceae auctt. p. p. 



Stems simple, bi- or tripinnate, the branches lateral, of the Frullania type, 

 and as subfloral innovations. Rhizoids in tufts, from the lamina of the under- 

 leaves, rarely on the male bracteoles, often from a one-layer rhizoid pad. Line of 

 leaf insertion transverse, or oblique with the leaves suecubous. Leaves (3-) 4- 

 6-9-parted to one-half of their length or more ; segments simple, or branched with 

 few to many long, simple or branched cilia, occurring singly, in opposite pairs, 

 or in whorls. Underleaves large, quadrifid, or with additional smaller segments, 

 often bisbifid to one-half of their length or more, the segments like the leaf- 

 segments. Male inflorescence terminal becoming intercalary on the stem or 

 branch, the bracts and bracteoles similar to and larger than the leaves and un- 

 derleaves or more elaborate ; antheridia large, in the axils of the bracts. Female 

 inflorescence terminal on the stem or a branch, without or with one or two sub- 

 floral innovations, the bracts and bracteoles in several series, similar to the leaves 

 and underleaves, or often more elaborate. Sporophyte covered by a shoot-calyp- 

 tra and a perianth, or a partial coelocaule capped by a short perianth above the 

 level of the capsule, or a thick, fleshy coelocaule covered with scales and paraphyl- 

 lia, the unfertilized archegonia at the tip, with no indication of a perianth. 

 Capsule wall thick, of four to seven layers, the outermost layer of large cells, 

 the other layers of smaller cells. 



Type genus: Trichocolea Dumortier, corr C. G. Nees. 



The members of this family are found primarily in the Southern Hemisphere. 

 The family is of special significance because of the two major evolutionary ten- 

 dencies that it exhibits. In Trichocolea there are only minor differences among 

 the species in vegetative characters, such as stem, leaves, and underleaves; the 

 major changes have come in the shoot/sporophyte relationship. There are, at the 

 present time, three distinct types : a perianth enclosing a shoot-calyptra ; a partial 

 coelocaule with a small perianth at the top ; and a thick coelocaule with unferti- 

 lized archegonia at the tip. In the other genus of the family, Temnoma, the 

 sporophyte/shoot relationship has remained essentially unchanged, a simple 

 three-keeled perianth, while the leafy stems have undergone drastic reductions. 

 The principal changes have been a decrease in the size of the plants, and a 

 reduction in size and number or a loss of cilia on the leaves and underleaves. 

 The female bracts and bracteoles of even the most simplified of the species have 

 retained the cilia to a greater or lesser degree. 



Trichocolea Dumortier, corr. C. G. Nees, Nat. Eur. Leberm. 3: 103. 1838. 



Thricholea Dumortier, Comm. Bot. 113. 1822. 

 Tricholea Dumortier, Anal. Fam. 69. 1829. Nomen nudum. 

 Thricolea Dumortier, Syllog. Jungerm. 24, 28, 66. 1831. 

 Leiomitra Lindberg, Acta Soc. Sci. Fenn. 10: 515. 1875. 

 Basichiton Trevisan, Mem. 1st Lomb. 13: 394. 1877. 



Plants in mats, tufts or scattered among other bryophytes, prostrate to sub- 

 erect, whitish-green to yellowish-green ; stems simple to bi- or tripinnate, the 

 branches lateral, of the Frullania type, with the dorsal half-leaf at the base of 

 the branch ; stems in transverse section with a cortical band of one to several 

 layers of somewhat smaller cells surrounding the many large cells of the medulla ; 

 stem with or without filamentous paraphyllia. Rhizoids when present from a 

 unistratose rhizoid pad on the lamina of the underleaf or occasionally on the 



