154 American Midland Naturalist Monograph No. 6 



F.-i-.i'.'y P. Timmtaceae 



Dioicous or autoicous; robust, in more or less high, lax, dull-gieen to yel- 

 lowish-green tufts, brownish inside, with a brown tomentum below: stem erect 

 or procumbent, with central strand, densely-leaved, simple or dichotomous; 

 leaves 8-seriatc, of uniform length, from a half-sheathing, non decurrent base 

 spreading to recurved, elongate lance-linear, carinate; lamina unistratose, chan- 

 neled to concave, non-bordered, serrate; costa strong, percurrent, often dorsally 

 toothed above, with several median guides; leaf-cells green, small, rounded to 

 4-6-sided, ventrally mamilkte; cells of the sheathing part without chlorophyll, 

 sometimes dorsally papillose, elongate-rectangular to linear, narrow towards 

 the margin: sporogonia solitary; seta long, erect; capsule cernuous to almost 

 pendent, from a short collum oblong-oval, brown, not or but slightly striate, 

 when dry ribbed; annulus revoluble; peristome inserted back from the cdr;e of 

 the mouth, always double, the inner as long as the outer, when dry the parts 

 sharply bulged outwards in the middle; teeth 16, confluent at the base, broadly 

 lance-linear, rarely split, plane, below yellowish and transversely striate-punc- 

 tate, above whitish and vertically papillose-striate, divisural zigzag, dorsal 

 plates low. sometimes cut by cross-walls; inner peristome free, yellow, basal 

 membrane high, carinate, transversely striate, dividing into 64 filiform, papil- 

 lose cilia, united apically into groups of fours, generally appendiculate on the 

 inner side: spores .012-. 023 mm, yellow, almost smooth; operculum hemi- 

 spheric, often apiculate; calyptra cucullate, long and narrow, often remaining 

 on the seta. 



One genus with characters as for the family; 8 species; 4 in North Amer- 

 ica, one in our range 



1. TiMMiA Hedwig 

 1. TiMMiA cucuLLATA Richard* 



(T. megapoiitana American authors, in part; T. megapolkana 

 var. cucullata (Richard) Sayre 



Plate XXIX 



Loosely cespitose, bright green above, brownish below: stems erect, spar- 

 ingly branched, radiculose below; leaves lanceolate to lance linear, spreading 

 from a concave appressed and more or less sheathing base, acute to subacute, 

 the margins serrate almost to the sheathing base, the spreading portion of the 

 leaf about as wide as the sheath, concave, smooth on back or more or less 

 involute; costa rather narrow, strong, ending in the apex; basal leaf-cells elon- 

 gate-rectangular, rather thin-walled, hyaline, hardly inflated, in upper part of 

 sheathing base becoming shorter to quadrate, and incrassate, the outer walls 

 bulging so as to appear slightly papillose, about .010 mm in diameter: seta 



* Timmia megapoiitana Hedwig ranges south to No v Jersey, New York, and Mis- 

 souri, and might occur in our region. Its lea\es are narrowed gradually to the apex 

 instead of suddenly as in T. cucullata; the mouth of the capsule when dry not wider than 

 rest of the capsule in megapoiitana, but flaring in cucullata. — See Sayre in Groit's Moss 

 Flora. 



