626 POTTIACEAE · Syntrichia Sexual condition dioicous. Seta 6–15 mm, brown. Dry soil, rock; moderate to high elevations; B.C.; Ariz., Capsule red, 2.5–3.2 mm, straight or slightly curved, with Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, a distinct neck; operculum 1.5–2mm, red; peristome 0.7– Wash.; Mexico (Coahuila, Nuevo León); s Europe; c Asia. 1 mm, the basal membrane about 1/2 the total length. Syntrichia papillosissima is primarily a species of the Spores 7–8 µm, lightly papillose. Great Basin Desert north into the shrub-steppe ecosystems Soil, deserts and steppe, often forming extensive of the Columbia Basin, where it often occurs as a co- carpets; moderate to high elevations; Alta., B.C.; Ariz., dominant with S. ruralis and S. caninervis. It is similar Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, to a robust S. ruralis, differing most conspicuously in the Wash., Wyo.; s, sw Asia (Afghanistan, Iran, Lebanon, extremely tall mammillae on the distal leaf cells, each Russia, Turkey); n Africa. crowned by only one or two papillae, unlike the shorter Syntrichia caninervis is most common in the colder bulging cell surface bearing four or five papillae deserts and steppes of the flora area, particularly in the characterizing other species in the S. ruralis complex. Mojave and Great Basin deserts and the Columbia Basin. Syntrichia papillosissima also has larger distal laminal It can be confused in the field with S. ruralis, but good cells, which are more pellucid than those of S. ruralis. field distinctions for S. caninervis include the blackish or olive green color, the imbricate, weakly twisted leaf stance 16. Syntrichia norvegica F. Weber, Arch. Syst. when dry, and the back of the costa showing no trace of Naturgesch. 1(1): 130, plate 5, fig. 1. 1804 red and often having a frosty appearance because of the Tortula norvegica (F. Weber) stellate papillae. Microscopically, S. caninervis is unique 5 Lindberg with its combination of 2-stratose laminae, non-bulging 5 cell surfaces, and costal cross-sections with sub-stereid Stems 8–25 mm. Leaves clasping at base, infolded and twisted 5 cells. 5 5 5 around the stem when dry, 5 5 5 5 5 5 squarrose-recurved when moist, 15. Syntrichia papillosissima (Coppey) Loeske, 5 5 5 Hedwigia 49: 44. 1910 lingulate-ovate, 2.5–3.5 × 1–1.2 mm, canaliculate to keeled; Barbula papillosissima Coppey, Bull. margins tightly revolute in the Séances Soc. Sci. Nancy, sér. 3, 8: proximal 3/4; apices acute to acuminate; costa excurrent 314, plate 2, figs. f, g. 1908; B. into a serrulate or sometimes serrate, hyaline awn that is ruralis var. hirsuta Venturi; Tortula often red at base or throughout but sometimes broadly 5 papillosissima (Coppey) Brotherus; 5 hyaline at base, papillose abaxially and sometimes 5 5 5 T. ruralis var. hirsuta (Venturi) Paris 5 5 serrulate near the apex because of projecting cell ends, 5 5 5 5 Stems 10–25 mm. Leaves clasping red-brown; basal cells abruptly differentiated, rectangular, at base, infolded and twisted 45–100 × 16–23 µm, quadrate to narrowly rectangular around the stem when dry, at the margins; distal cells quadrate, polygonal, or squarrose-recurved when moist, lingulate-ovate, 2.5–4 rectangular, 13–18 µm, with 3–6 papillae per cell, bulging, × 1–1.6 mm, canaliculate to keeled; margins tightly somewhat collenchymatous. Specialized asexual revolute in the proximal 3/4–7/8, entire; apices obtuse to reproduction absent. Sexual condition dioicous. Seta acute; costa excurrent into a serrate, hyaline awn that is brown, 15–20 mm. Capsule red-brown, 3–4 mm, slightly often brown, sometimes broadly hyaline at base, strongly curved, with an abrupt neck; operculum ca. 1.8 mm, papillose abaxially and serrate because of projecting cell brown; peristome ca. 1.8 mm, the upper divisions twisted ends, yellow-brown; basal cells abruptly differentiated, ca. 2 turns, red, the basal membrane white, 1/3–1/2 the rectangular, 45–90 × 15–23 µm, quadrate to narrowly total length. Spores 11–15 µm, papillose. rectangular at the margins; distal cells quadrate to Soil, rocks; high elevations; Greenland; Alta., B.C., polygonal, 11–18 µm, with tall, bulging mammillae, Ont.; Alaska, Ariz., Calif., Colo., Idaho, Mich., Mont., bearing 1–2 papillae per cell, thick-walled and sometimes Nev., N.Mex., Oreg., Wash.; Mexico; n, c Europe; Asia; collenchymatous. Specialized asexual reproduction Africa (South Africa). absent. Sexual condition dioicous. Seta brown, 12–18 Syntrichia norvegica can be distinguished from S. mm. Capsule brown, 3–5 mm, curved, with an abrupt ruralis by its larger laminal cells, leaf margins less recurved neck; operculum ca. 2 mm; peristome ca. 1.8 mm, the distally, and apices consistently acute to acuminate. The upper divisions twisted ca. 2 turns, yellow-brown, the awn is often partially to completely red, but the amount basal membrane white, ca. 1/2 the total length. Spores of color seems to vary with shade and is not considered 10–14 µm, papillose. Syntrichia· Microbryum · POTTIACEAE 627 definitive. Another potential recognition feature in the condition dioicous. Seta red, 5–10 mm. Capsule red- field is that the stereid band in the costa often disappears brown, 2–3.5 mm, straight, with an abrupt neck; near the apex, making the normally reddish costa appear operculum 1.25–1.75 mm, brown; peristome ca. 1.25 green just before the awn. Note that there are frequent mm, the upper divisions twisted ca. 2 turns, red, the basal neotenic forms of this species that lack an awn. membrane white, about 1/3 the total length. Spores 11– 15 µm, papillose. 17. Syntrichia ruralis (Hedwig) F. Weber & D. Mohr, Dry to moist soil and rock; low to high elevations; Index Mus. Pl. Crypt., [2]. 1803 Greenland; Alta., B.C., Nfld. and Labr. (Nfld.), N.S., Ont.; Barbula ruralis Hedwig, Sp. Musc. Alaska, Ariz., Calif., Colo., Idaho, Maine, Mass., Mich., Mont., Mo., Nev., N.Y., Okla., Oreg., S.Dak., Tex., Utah, 5 Frond., 121. 1801; Syntrichia ruraliformis (Bescherelle) Dixon; Wash., Wyo.; Mexico; s South America; Eurasia; s Africa. Tortula ruraliformis (Bescherelle) Syntrichia ruralis generally has conspicuously 5 5 squarrose-recurved leaves when wet, with margins 5 W. Ingham; T. ruralis (Hedwig) P. 5 5 5 5 5 5 recurved nearly to the apex, distal portions of the costa 5 5 5 5 5 Gaertner, B. Meyer & Scherbius 5 5 5 5 5 5 toothed abaxially because of projecting cell ends, and 5 5 5 5 Stems 5–15 mm. Leaves clasping relatively small laminal cells. The decurrent, hyaline base at base, infolded and twisted of the awn sometimes used to distinguish S. ruraliformis around the stem when dry, wide- is not reliable and can, on occasion, be found in S. spreading (in smaller forms) to squarrose-recurved when princeps, S. papillosissima, and S. norvegica. Specific moist, lingulate-ovate, 1.5–3.5 × 0.75–1.25 mm, distinctions in the S. ruralis complex are subtle, for the canaliculate to keeled; margins tightly revolute in the most part, requiring cross sections of leaves and stems, 7 proximal /8 or more, entire; apices emarginate to acute; and careful measurements. The leaves of S. princeps and costa excurrent into a serrate (or occasionally only faintly S. obtusissima are narrowed near the middle, whereas serrulate), hyaline awn that is often red or sometimes those of S. papillosissima, S. norvegica, and S. ruralis are broadly hyaline at base, weakly to strongly papillose on widest about one-third the way up from the base and the abaxial surface and often serrate near the apex then taper to the apex. The stem of S. princeps and S. because of projecting cell ends, red-brown; basal cells obtusissima has a strong central strand of thinner-walled abruptly differentiated, narrowly rectangular, 35–70 cells, the costa has a group of hydroids just abaxial to (–90) × 11–18 µm, quadrate to narrowly rectangular at the guide cells, and the basal cells in the leaf are relatively the margins; distal cells quadrate to polygonal, 8–12 µm, wide. In S. papillosissima, S. norvegica, and S. ruralis, with 3–6 papillae per cell, bulging, somewhat obscure. the stem lacks a central strand, the costa lacks hydroids, Specialized asexual reproduction absent. Sexual and the basal cells in the leaf are relatively narrow. 34. MICROBRYUM Schimper, Syn. Musc. Eur., 10. 1860 · [Greek mikros, small, and bryon, moss] Richard H. Zander ˆ Phascum sect. Microbryum (Schimper) Podpera; Phascum subg. Microbryum (Schimper) Limpricht; Phascum sect. Pottiella (Limpricht) Paris; Phascum subg. Pottiella Limpricht; Pottia sect. Pottiella (Limpricht) Nyholm; Pottia subg. Pottiella (Limpricht) Brotherus Plants in a low turf, scattered or gregarious, occasionally bulbiform, reddish brown distally, brown proximally. Stem very short, 0.2–0.4 mm, hyalodermis absent, sclerodermis absent or weakly differentiated, central strand present or absent; axillary hairs of 3–6 cells, the proximal 1-2 cells usually with thicker walls. Leaves appressed when dry, weakly spreading, tips occasionally reflexed when moist, lanceolate, elliptical or ovate, adaxial surface weakly concave to broadly channeled, short, 0.6–1.8 mm; base not differentiated, proximal margins not differentiated; distal margins recurved at mid leaf and commonly recurved to near apex, entire or rarely serrulate near apex, margins occasionally less papillose and somewhat thicker walled than medially; apex broadly acute; costa excurrent as an apiculus, mucro or short awn, 628 POTTIACEAE · Microbryum occasionally only percurrent, adaxial outgrowths occasionally present as a pad of enlarged parenchymatous