BFNA Title: Sematophyllum
XX. SEMATOPHYLLUM Mitten, J. Linn. Soc. Bot. 8: 5. 1864 * [Greek semat, mark, and phyllon leaf, alluding to the inflated row of alar cells]
W. B. Schofield†
Plants small to robust, forming glossy yellow-green mats. Stems 0.5--4 cm, red-brown, with creeping to suberect irregularly branched shoots, pseudoparaphyllia foliose. Leaves erect-spreading to falcate-secund, often homomallous, lanceolate to broadly ovate, acute to acuminate; margins entire except in apiculus, sometimes reflexed proximally; costa short and double or absent; laminal cells smooth or rarely 1-papillose, rhomboid to flexuose medially, alar cells as a basal row of somewhat to strongly inflated and enlarged pigmented group, supra-alar cells quadrate or short and irregular. Sexual condition autoicous or dioicous. Seta reddish, smooth 0.5--2 cm. Capsule short cylindric, inclined to pendent, rarely erect, asymmetric; operculum rostrate; exothecial cells collenchymatous; peristome double.
Species ca. 50 (4
in the flora): widespread in temperate to circumtropical regions, the flora
region, confined to eastern forests, but introduced to
As W. R. Buck (1998) has noted, Sematophyllum is a catch-all genus, and is in need of a world monograph. The four North American species, however, are reasonably treated in a single genus, Sematophyllum.
SELECTED REFERENCES Buck, W. R. 1998. New combinations and new synonymy in Brazilian Sematophyllaceae. Nova Hedw. 66: 241--246.
1. Leaves oblong-ovate, tapering abruptly to short acumen, not markedly glossy . . . 4. Sematophyllum subpinnatum
1. Leaves oblong-lanceolate, tapering gradually to acumen, usually markedly glossy.
2. Plants relatively robust, leaves 1.5--2 mm; alar cells inflated, in several rows of enlarged cells; usually on rock. . . . 3. Sematophyllum marylandicum
2. Plants small, leaves usually less than 1.4 mm; alar cells with one row of elongate inflated cells; epiphytic or occasionally on rock.
3. Branches of shoots often curving upwards, leaves mainly homomallous dorsally; distal leaf cells nearly the same length as the medial; leaves tapering to acumen in distal third of leaf; commonly on wood, logs, tree-bases, occasionally on rocks . . . 1. Sematophyllum adnatum
3. Shoots mainly weakly homomallous; distal leaf cells shorter than the medial, leaves tapering gradually to narrow acumen; commonly on rocks near streams . . . 2. Sematophyllum demissum
1. Sematophyllum adnatum (Michaux) E. G. Britton, Bryologist 5: 65. 1902
Leskea adnata Michaux, Fl. Bor.-Amer 2: 310. 1803
Plants small, in green to golden-yellow mats. Stems creeping, 2--3 cm, branches irregular, ascending. Leaves crowded, erect to erect-spreading, sometimes homomallous, 1--1.5 mm, oblong-lanceolate, gradually acuminate, margins entire, reflexed; laminal cells smooth, long-rhomboidal throughout except alar region of a row of enlarged, yellow, inflated cells with quadrate to short-rectangular supra alar cells. Specialized asexual reproduction rare, by 1-seriate, rough, branched or unbranched axillary propagula. Sexual condition autoicous. Seta 4--8 mm. Capsule erect, ca. 1 mm.
Logs, bark of tree bases, commonly in
Sematophyllum adnatum resembles Pylaisia in habit, but the strongly differentiated, elongate (not isodiametric) alar cells quickly distinguish it.
2. Sematophyllum demissum
Syn. Musc. Frond. 2: 327. 1851
Plants small to medium sized, forming green to yellow-green, glossy mats. Stems 0.5--2.5 cm; branches irregular, sometimes ascending. Leaves mainly straight or occasionally homomallous, 1--1.2 mm, oblong-ovate, gradually tapering to acumen; margins entire, reflexed proximally; laminal cells smooth and rhombic to flexuose; alar cells in well-defined group, with proximal row elongate and enlarged, usually yellow; supra-alar cells few, quadrate to short. Specialized asexual reproduction lacking. Sexual condition autoicous. Seta 8--12 mm. Capsule inclined to horizontal, ca. 1 mm, nearly symmetric.
Wet siliceous rocks near streams; N.S.; Ala., Ark., Conn., Fld., Ga., Iowa, Kans., La., Mich., Mo., N.Y., N.C., Ohio, Pa., Okla., S.C., Tenn.
Sematophyllum demissum resembles Hageniella micans in many respects, but the strong double costa of that species, as well as its toothed acumen, separate it. Also, Sematophyllum has collenchymatous exothecial cells, but those of Hageniella are not.
3. Sematophyllum marylandicum (Müller Hal.) E. G. Britton, Bryologist 5: 66. 1902 E
Hypnum marylandicum Müller Hal., Syn. Musc. Frond. 2: 328. 1851
Plants robust to middle-sized, forming green, yellow-green to golden brown glossy mats. Stems 3--5 cm; branches creeping, irregular. Leaves erect to erect-spreading, 1.5--2 mm, oblong-ovate, tapering gradually to acumen, or sometimes with an apiculus; costa double; margins entire; laminal cells smooth, flexuose in body of leaf; alar cells forming distinct group, yellow to yellow-orange or colorless, the proximal row inflated, elongate, conspicuously larger than other cells, supra-alar cells few, also distinct. Specialized asexual reproduction lacking. Sexual condition autoicous. Seta 1--2 cm. Capsule inclined to horizontal, 1--1.2 mm, somewhat asymmetric.
Mainly on wet rocks, either by streams or in cliffs; Nfld., N.S.; Ala., Conn., Ga., Ky., Md., N.Y., N.C., Ohio, Pa., Tenn., Vt., W.Va.
4. Sematophyllum subpinnatum (Bridel) E. G. Britton, Bryologist. 21: 28. 1918
Leskea subpinnata Bridel, Muscol. Recent. Suppl. 2: 54. 1812; Sematophyllum caespitosum (Swartz) Mitten
Plants small to medium-sized, in rather dull green or yellowish mats; branches reclining irregular. Stem 0.3--0.6 cm. Leaves crowded, homomallous, 0.5--1.1 mm, ovate to oblong-lanceolate, short-acuminate; margins reflexed from base to near apex, entire; laminal cells smooth, rhomboidal to elliptic; alar cells mainly of an elongate basal row, somewhat enlarged but not inflated, supra-alar cells in several rows, mainly quadrate. Specialized asexual reproduction lacking. Sexual condition autoicous. Seta 5--10 mm. Capsule suberect, nearly symmetric, 1--1.5 mm.
Logs, bark of trees, mainly humid forests, sometimes soil; Fld., La; Mexico; West Indies; Central America; South America; e Asia; Africa; Pacific Islands (Hawaii); Australia.
Sematophyllum subpinnatum sometimes persists briefly in greenhouses.