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BFNA Title: Sematophyllum |
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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
swamps; Sematophyllum adnatum resembles Pylaisia in habit, but
the strongly differentiated, elongate (not isodiametric) alar cells quickly
distinguish it. 2. Sematophyllum demissum
( Hypnum 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. |
