10. TIMMIACEAE Schimper

Transcription

1 10. TIMMIACEAE Schimper Guy R. Brassard Plants acrocarpous, large. Stems stiff, erect, mostly unbranched, in cross-section with a cortical region of small, thick-walled cells, a parenchyma of larger, thin-walled cells, and a distinct central strand; rhizoids abundant, especially on the proximal stems and in the leaf axils, dark reddish black, coarsely papillose, ca µm wide. Leaves lanceolate or long-lanceolate, with a sheathing, entire base occupying the proximal 1 /6 1 /3 of leaf, and a non-sheathing, serrate limb; costa strong, single, subpercurrent to excurrent, in cross-section (mid-limb) with large guide cells, two bands of stereids, and enlarged abaxial and adaxial cells; cells of limb lamina irregularly isodiametric or quadrate, smooth, papillose or mammillose on adaxial and abaxial surfaces; cells of the sheath lamina rectangular. Seta terminal, elongate, erect, single or double, cm. Capsule pendulous to nearly erect, ovate to oblong-cylindric, smooth or broadly plicate; annulus large, revoluble; operculum hemispheric or conic, with distinct mamilla at the tip; stomata numerous on the neck or over the entire urn; peristome diplolepideous; exostome of 16 lanceolate teeth sometimes united near the base, smooth or papillose proximally, strongly vertically barred and papillose distally, with prominent projecting lamellae on the interior surface; endostome about the same height as the exostome, with a high basal membrane about half the height of the exostome, and 64 irregularly anastomosing, nodose cilia papillose externally and smooth or appendiculate on the interior surface. Calyptra linear-cylindrical. Genus 1, species 4 (4 in the flora): North America, Eurasia, n Africa, Pacific Islands (Hawaii, New Zealand). Timmiaceae is a small, taxonomically isolated family. 1. TIMMIA Hedwig, Sp. Musc. Frond., [For Joachim Christian Timm, , botanist and Burgermeister of Malchin, Mecklenberg, Germany] Plants (1 )2 9( 13) cm, in compact or loose tufts, brownish proximally, bright to yellowish green distally. Leaves crisped to imbricate (and occasionally inrolled) when dry, erect-patent to spreading when moist, (1.5 )2 8( 12) mm, mm wide at mid-limb; cells of the sheath lamina longer and narrower near the margins, shorter and broader near the limb-sheath 165

2 166 TIMMIACEAE Timmia transition, smooth on the adaxial surface, smooth or with a series of linearly-arranged, large round papillae on the abaxial surface of the lumens. Sexual condition monoicous or dioicous; male gametophyte (in dioicous taxa) monopodial, with the stem continuing growth through terminal perigonia; paraphyses few, of 10 15( 40) cells, filiform, with fusiform tips; archegonia 1 6 per perichaetium, ca. 1 2 mm; antheridia 5 40 per perigonium, ca. 1 2 mm. Capsule ca mm; exothecial cells with smooth or sinuose walls; peristome diplolepideous; exostome teeth mm, yellow in proximal half, pale or hyaline distally; endostome hyaline or yellowish, with a high basal membrane about half the height of the exostome, and 64 irregularly anastomosing, nodose cilia papillose externally and smooth or appendiculate on the interior surface. Spores round, finely papillose, pale yellow or brown, µm. Species 4 (4 in the flora): North America, Eurasia, n Africa, Pacific Islands (Hawaii, New Zealand) in arctic, boreal, montane, and temperate areas. SELECTED REFERENCES Brassard, G. R The moss genus Timmia. 1. Introduction, and revision of T. norvegica and allied taxa. Lindbergia 5: Brassard, G. R The moss genus Timmia. 2. Sect. Timmiaurea. Lindbergia 6: Brassard, G. R The moss genus Timmia. 3. Sect. Timmia. Lindbergia 10: Cells at leaf insertion not hyaline and fragile, leaves not readily breaking away from stem. 2. Leaf sheaths bright, clear orange (appearing red when still on the stem); cilia of endostome non-appendiculate; dioicous [Sect. Timmiaurea] Timmia austriaca 2. Leaf sheaths pale, uncoloured or yellowish; cilia of endostome appendiculate; monoicous [Sect. Timmia] Timmia megapolitana 1. Cells at leaf insertion hyaline and fragile, leaves readily breaking away from stem [Sect. Norvegicae]. 3. Abaxial surface of mid-limb cells non-mamillose and non-papillose Timmia norvegica 3. Abaxial surface of mid-limb cells mamillose and pluripapillose (as seen in cross section) Timmia sibirica 1. Timmia austriaca Hedwig, Sp. Musc. Frond., 176, plate 42, figs Timmia arctica Kindberg; T. austriaca var. arctica (Kindberg) Arnell; T. austriaca var. brevifolia Renauld & Cardot; T. austriaca var. papillosa Hesselbo Plants without deciduous distal leaves. Leaf apex acute (but with terminal 4 5 cells often truncated); costa subpercurrent; sheath orange but appearing red when still on stem; limbs green, pellucid; limb-sheath transition abrupt, sharply angled; limb margins strongly dentate in distal 1 /3 1 /2, less dentate to entire proximally, occasionally crenulate or entire throughout; limb lamina cells 8 14( 16) 8 12( 13) µm, with low conical or rounded mamillae on the adaxial surface, abaxial surface smooth; distal sheath lamina cells smooth or with 1 6( 8) large round, often verrucose papillae over the abaxial surfaces of lumen; cells at leaf insertion not hyaline and fragile; abaxial surface of costa limb smooth, toothed or papillose near apex, adaxial cells with conical or rounded mamillae. Sexual condition dioicous; perichaetial leaves more strongly dentate than vegetative leaves, sheath up to half the leaf length. Calyptra without longitudinal split, not persistent on seta. Capsule spirally plicate (even when young and operculate); exothecial cell walls sinuose; stomata mostly on the neck; endostome cilia without appendiculations on the interior surfaces. Sporophytes sporadic throughout the range, but more frequent in non-arctic regions; various habitats including dry exposed ridges, wet river edges or forested valleys; low to high elevations ( m); Greenland; Alta., B.C., N.B., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Que., Sask., Yukon; Alaska, Calif., Colo., Idaho, Mich., Mont., Nev., N.Mex., Oreg., S.Dak., Wash., Wyo.; Eurasia (Alps, Greece, Italy, Pyrenees, Scandinavia, United Kingdom); Atlantic Islands (Iceland); e Asia (Russia). A polymorphic yet remarkably well-defined species, Timmia austriaca has the most well-delimited sheath of all Timmia taxa, with an abrupt change in color and sharp angle at the limb-sheath transition, and it is the only taxon where the costa widens slightly just at the limb-sheath transition. Its distinct habit and leaf angularity, dioicous sexuality, non-appendiculate endostome cilia, and orange sheaths separate it from T. megapolitana, while its habit, leaf angularity, and non-deciduous leaves will separate it from T. norvegica and T. sibirica. The perigonial leaves are short and broad, consisting mostly of sheath.

3 Timmia TIMMIACEAE 167 TIMMIA 2. Timmia megapolitana Hedwig, Sp. Musc. Frond., Plants without deciduous distal leaves. Leaf apex acute; costa subpercurrent; sheath clear or yellowish; limb green, pellucid; limb-sheath transition abrupt, not sharply angled; limb margins strongly dentate in distal half, with fewer and smaller teeth below, and a few small sharp teeth at limbsheath transition; limb lamina cells (5 )7 16( 21) (6 )7 12( 14) µm, with low rounded or flattened mamillae on the adaxial surface, abaxial surface smooth; abaxial surfaces of sheath lamina cells smooth or with 1 6 papillae over lumen; cells at leaf insertion not fragile and hyaline; abaxial surface of limb costa smooth (rarely papillose near leaf apex), adaxial cells with rounded or somewhat flattened mamillae. Sexual condition monoicous; perichaetial leaves narrower than vegetative leaves. Calyptra with a median longitudinal split, sometimes persistent on the neck of the capsule or seta. Capsule plicate or puckered when dry; exothecial cells with non-sinuose walls; stomata on urn; endostome cilia with numerous spine-like or branched-stellate Subspecies 2 (2 in the flora): North America, Eurasia, n Africa, Atlantic Islands (Iceland), Pacific Islands (Hawaii). Timmia megapolitana is a distinct species within the genus, separated by its monoicous sexuality, distinct but pale leaf sheaths, and elaborately appendiculate endostome cilia. 1. Cells of mid-limb lamina (8 )9 12( 14) µm wide; cells of distal part of leaf sheath papillose; calyptra often remaining attached to seta at base of capsule a. Timmia megapolitana subsp. megapolitana 1. Cells of the mid-limb lamina (6 )7 10( 12) µm wide; cells of distal part of leaf sheath smooth; calyptra not persistent on seta b. Timmia megapolitana subsp. bavarica 2a. Timmia megapolitana Hedwig subsp. megapolitana Indian feather moss Timmia cucullata Michaux Cells of mid-limb lamina (8 )9 12( 14) µm wide (mean 10.5 µm); cells of distal part of leaf sheath with 1 6 papillae on the abaxial surface. Calyptra often remaining attached to setae at base of capsule. Almost always with sporophytes. Most often in deciduous forests, on humus in moist, shady calcareous sites, northwards in forested localities, especially along major rivers, and as an

4 168 TIMMIACEAE Timmia adventive in disturbed sites such as lawns, golf courses or cemeteries; low to moderate elevations (0 500 m); Alta., B.C., Man., N.W.T., N.S., Ont., Que., Sask., Yukon; Alaska, Ark., Conn., Ill., Ind., Iowa, Ky., Mass., Mich., Minn., Mo., Mont., Nebr., N.J., N.Y., Pa., S.Dak., Tenn., Vt., Va., Wis.; Eurasia (China, Finland, Germany [extinct], Netherlands, Russia). Subspecies megapolitana is the only taxon in the genus that is not an arctic or montane moss; it occurs primarily in temperate regions, and sporadic in the boreal region. It is also the only taxon occurring in man-made habitats. The common name reflects the resemblance of the erect, persistent calyptra to the feather headdresses used by some North American Indians. 2b. Timmia megapolitana subsp. bavarica (Hessler) Brassard, Lindbergia 10: Timmia bavarica Hessler, De Timmia, 19, fig ; T. megapolitana var. bavarica (Hessler) Bridel Cells of the mid-limb lamina (6 )7 10( 12) µm wide (mean 8.5 µm); cells of distal part of leaf sheath non-papillose on abaxial surface (rarely papillose in non- North American specimens). Calyptra not persistent on seta. Often with sporophytes. Most often in mesic, calcareous, open or well-vegetated Arctic-montane sites, or in nutrient-rich sites such as the bases of cliffs or around large boulders; low to high elevations ( m); Greenland; Alta., B.C., Man., N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Ariz., Colo., Idaho, Mont., Nev., N.Mex., Utah, Wyo.; Mexico; Eurasia (Caucasus, China, n, c Europe, Greece, India, Japan); n Africa (Algeria); Atlantic Islands (Iceland); Pacific Islands (Hawaii). 3. Timmia norvegica J. E. Zetterstedt, Öfvers. Kongl. Vetensk.-Akad. Förh. 19: Plants with deciduous, longer distal leaves with a less welldeveloped sheath. Leaf apex acute or acuminate; costae ending a few cells below apex or excurrent; sheath clear in the distal leaves, orange-brown to reddish black in the proximal leaves; limb green, pellucid; limb-sheath transition gradual; limb margins coarsely dentate in distal 1 /3 1 /2, slightly toothed, crenulate or ± entire proximally; limb lamina cells 6 16( 18) 6 14 µm, with tall rounded mamillae on the adaxial surface, abaxial surface smooth; sheath lamina cells with (0 )1 6( 8) large round, verrucose papillae over abaxial surface of the lumen; cells at leaf insertion abruptly differentiated into 1 to a few rows of fragile, hyaline cells; limb costa papillose on abaxial surface, or toothed near the apex, adaxial cells with tall bottle-shaped mamillae. Sexual condition dioicous; perichaetial leaves longer and more evenly tapering than stem leaves, sheath poorly developed. Calyptra unknown. Capsule non-plicate; exothecial cells with extremely sinuose walls; stomata on neck and proximal urn; endostome cilia with numerous short blunt Varieties 2 (2 in the flora): North America, Eurasia, Atlantic Islands (Iceland), Pacific Islands (New Zealand). Timmia norvegica is related to T. sibirica, with which it shares the important character of fragile leaf bases; however, the papillosity of the limb in T. sibirica is a strongly differentiating character. Timmia norvegica differs from T. austriaca and T. megapolitana by having fragile leaf bases, heterophyllous leaves, and less well delimited leaf sheaths. 1. Leaves 3 8( 12) mm, mm wide at midlimb; cells of mid-limb lamina (8 )9 16( 18) (8 )9 14 µm; base of costa dark; never with loose clusters of linear leaves at stem tips a. Timmia norvegica var. norvegica 1. Leaves 2 6 mm, mm wide at mid-limb; cells of mid-limb lamina 6 10( 11) 6 9( 10) µm; base of costa pale; stem tips often with loose deciduous clusters of almost linear leaves b. Timmia norvegica var. excurrens 3a. Timmia norvegica J. E. Zetterstedt var. norvegica Plants robust. Leaves 3 8( 12) mm, mm wide at midlimb; cells of mid-limb lamina (8 )9 16( 18) (8 )9 14 µm; costa ending below apex, papillose on abaxial surface of sheath and limb; base of costa dark and swollen, more strongly attached to stem than is the lamina; with distal leaves often larger and deciduous, but never with loose clusters of linear leaves at stem tips. Sporophytes extremely rare. Wet calcareous sites such as seepage slopes, moist crevices or cliff ledges, snow patches, edges of small creeks and ponds in Arcticmontane areas, often intermixed with other mosses, including Timmia sibirica, T. norvegica var. excurrens, and T. austriaca; low to high elevations ( m); Greenland; Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Que., Yukon; Alaska, Colo., Mont.; Eurasia (Alps, Russia, Scandinavia, United Kingdom); Atlantic Islands (Iceland); Pacific Islands (New Zealand).

5 Timmia TIMMIACEAE 169 Only three sporulating specimens of var. norvegica are known (one from Alaska). The deciduous leaves undoubtedly act as vegetative propagules. 3b. Timmia norvegica var. excurrens Bryhn, Bryoph. Itin. Pol. Norv., Timmia comata Lindberg & Arnell; T. norvegica var. comata (Lindberg & Arnell) H. A. Crum Plants generally smaller and more delicate than those of var. norvegica. Leaves 2 6 mm, mm wide at mid-limb; cells of mid-limb lamina 6 10( 11) 6 9( 10) µm; costa excurrent, smooth on abaxial surface of sheath, smooth or slightly papillose on abaxial surface of the limb, with one several teeth at back near the apex; base of costa pale and not strongly attached to the stem; stem tips often with loose deciduous clusters of almost linear leaves (ca mm). Calcareous areas, often on shaded limestone cliffs near rivers in Arctic and boreal regions, intermixed with other mosses, including other taxa of Timmia; low to moderate elevations ( m); Greenland; Nfld. and Labr. (Nfld.), N.W.T., Nunavut, N.S., Que, Yukon; Alaska; Eurasia (Scandinavia, Switzerland, Poland, Russia); Atlantic Islands (Iceland). Variety excurrens is known also as a Quaternary subfossil from New York and Vermont. Variety excurrens is not known to occur with sporophytes, but the deciduous leaves no doubt act as vegetative propagules. 4. Timmia sibirica Lindberg & Arnell, Kongl. Svenska Vetensk. Acad. Handl., n. s. 23(10): Timmia norvegica J. E. Zetterstedt var. crassiretis Hesselbo Plants with deciduous longer distal leaves with a less well-developed sheath. Leaf apex acute to slightly acuminate; costa percurrent or subpercurrent; sheath clear in the distal leaves, clear or dark reddish black in the proximal leaves; limb green, non-pellucid; limb-sheath transition gradual; limb margins dentate in distal 1 /3 1 /2, crenulate or slightly toothed proximally, limb lamina cells (8 )11 18( 22) (9 )10 19 µm, mammillose and with 2 4 papillae on the adaxial surface, with 2 4 papillae and generally also mammillose on the abaxial surface; cells of the sheath lamina with (0 )1 8( 10) large round, often verrucose papillae over the abaxial surface of the lumens; cells at leaf insertion abruptly differentiated into 1 to a few rows of fragile, hyaline cells; limb costa with the abaxial cells 1- or pluripapillose, and the adaxial cells mammillose and pluripapillose. Sexual condition dioicous; perichaetial leaves longer and more evenly tapering to the apex than stem leaves, with the sheath poorly developed; perigonial leaves shorter than stem leaves, consisting mostly of the sheaths, abruptly apiculate. Calyptra without longitudinal split, not persistent on seta. Capsule non-plicate (only immature ones known); exothecial cells with very sinuose walls; stomata on the neck; endostome cilia with numerous blunt Only one sporulating specimen is known (from Alaska), but the capsules are immature. Wet or moist, predominantly calcareous sites, often near small streams, on seepage slopes, near snowmelt areas, or in depressions in open tundra; frequently intermixed with other mosses, including other species of Timmia; low to moderate elevations ( m); Greenland; Alta., B.C., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Que., Yukon; Alaska; Europe (Norway, Russia). Timmia sibirica is a very distinct species: the limb lamina and limb costa cells that are mamillose and pluripapillose on both surfaces are unique within the genus. It is an Arctic species, rare south of 65 N. Timmia sibirica has somewhat larger leaf cells than T. norvegica (and the largest cells of any Timmia taxon), and it has deciduous leaves that can aid in vegetative dispersal.