Grimmia trichophylla v. indianensis Reviewed

Abstract

Grimmia trichophylla Grev. v. indianensis Sayre is considered more closely related to G. pulvinata (Hedw.) Sm. and G. orbi-claris Bruch ex Wils. than to G. trichophylla, and it seems sufficiently distinct to be recognized at the specific level. It is redescribed and two recent collections of G. pulvinata are reported from Missouri as geographic evidence of a probable relationship. 1 National Museum of Canada, Ottawa, Ontario. This content downloaded from 207.46.13.160 on Mon, 17 Oct 2016 04:45:51 UTC All use subject to http://about.jstor.org/terms 234 THE BRYOLOGIST [Volume 68 Grimmia indianensis (Sayre) Crum comb. nov. Grimmia trichophylla Grev. v. indianensis Sayre, THE BRYOLOGIST 57: 21. 1954. Small plants in dense, dull, extensive mats, yellow above, dark brown below, sparsely branched, 1-1.5 cm high. Leaves erect and scarcely contorted when dry, erect or erect-spreading when moist, 2-2.5 mm long, keeled, oblong-lanceolate, gradually narrowed to an acute apex, the perichaetial leaves often ending in a very short, inconspicuous, smooth, hyaline point; margins bistratose above, revolute below (especially near the middle, sometimes nearly to the apex), more strongly so on one side; costa prominent at back, subpercurrent; upper cells about 8p/ wide, subquadrate, incrassate and sinuose; basal cells subquadrate to short-rectangular, 1-2:1, rather thin-walled and only slightly sinuose, with somewhat thickened cross-walls, especially toward the margins. Autoicous. Setae cygneous wet or dry, yellow, becoming dull brown with age, 4 mm long; capsules exserted, ellipsoidal, becoming oblong-cylindric when dry and empty, 1-1.2 mm long, irregularly plicate; annulus broad (of 3 rows of cells), probably not revoluble; operculum erect and stoutly rostrate; stomata superficial, in 2 rows at the extreme base of the urn; peristome teeth 16, lanceacuminate, brown, somewhat perforate above, finely papillose. Spores 10-11,c, spherical, smooth or nearly so. Calyptra cucullate, smooth, naked. INDIANA. WARREN CO.: On sandstone along small creek leading to Pine Creek on E side of road 2 mi SW of Rainsville, Welch 6986, 9694 (type), November 27, 1937. Although Sayre, with considerable logic, placed this species as a variety of Grimmia trichophylla Grev., I feel that it is distinct enough to warrant recognition at a higher level. Grimmia trichophylla does not resemble this species in general appearance because of its narrowly acuminate, somewhat flexuose leaves ending in well developed hyaline awns. Its basal cells, though varying from short and subquadrate to quite elongate, are thick-walled and clearly sinuose, and the calyptra is mitrate. (The annulus is particularly well developed in G. trichophylla. That of G. indianensis, seen only in immature capsules, seems to be less well marked.) The fact that G. trichophylla is dioicous, rather than autoicous, seems to me also a significant difference. Grimmia trichophylla is a montane species of western North America, too far removed geographically and ecologically from the prairie margins of Indiana to be a likely progener of the species under consideration. Grimmia pulvinata (Hedw.) Sm. seems to be more closely related to G. indianensis, and it is also autoicous. Although it has broadly oblong leaves and long awns, except in the f. viridis (Schimp.) Loeske, the basal cells of the leaf, though variable, are often short, rather thin-walled, and not very sinuose, and the cross walls may be somewhat thickened. The calyptra is mitrate, but in G. orbicularis Bruch ex Wils., which is obviously related to G. pulvinata, the calyptra is This content downloaded from 207.46.13.160 on Mon, 17 Oct 2016 04:45:51 UTC All use subject to http://about.jstor.org/terms 1965] CRUM: GRIMMIA INDIANENSIS 235 cucullate as in G. indianensis. (G. orbicularis is even further removed from G. indianensis, however, primarily because of unistratose leaf margins.) Grimmia pulvinata is common and widespread in western North America and would also be an unlikely choice of a close relative of G. indianensis, were it not for the fortunate coincidence that it has been found twice recently in Missouri. Neither collection is completely typical, but I have been unable to find any significant differences from the considerable variability of G. pulvinata. The basal cells are short and subquadrate, rather thin-walled, and only slightly sinuose, with somewhat thickened cross-walls, quite similar in fact to those of G. indianensis. The Missouri specimens are cited as follows: MISSOURI. VERNON CO.: Forming dense mats on exposed sandstone, about 4 mi SW of Eldorado Springs, Redfearn 8099 (CAN). CEDAR CO.: On rock along road near Sac River, 6 mi SE of Cedar Springs, Ireland 3509 (CAN). Bryophytes of the Cochrane River Region of Northwestern Manitoba