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BFNA Title: Pterygoneurum |
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PTERYGONEURUM - POTTIACEAE xxx. PTERYGONEURUM Juratzka, Laubm. Oest.
Ungarn 95, 1882, conserved name and orthography * [Greek pterux, -ugos, wing + o
+ Latin neuron, nerve; alluding to
the ridge-like costal lamellae] Richard H. Zander Plants bulbiform, gregarious or forming a
thin turf, green above, light brown below. Stems buried, usually short, 0.5--5 mm; hyalodermis absent,
sclerodermis absent, central strand present, distinct; axillary hairs ca. 7
cells in length, all hyaline or proximal 1--2 cells brown. Cauline leaves appressed when dry,
weakly spreading when moist; ovate to ligulate, adaxial surface broadly
concave, 2--3.5 mm (inclusive of the 1.5--2 mm awn); base not differentiated
in shape; distal margins weakly to broadly incurved to near apex, plane
below, entire or denticulate above; apex obtuse to rounded, often weakly
cucullate; costa long-excurrent as a smooth or denticulate, hyaline awn,
occasionally absent in some leaves, adaxial outgrowths of (0--)3--4 lamellae
longitudinally inserted on adaxial surface of costa, ca. 12 cells in height,
occasionally lobed or branching, smooth or hollow-papillose, adaxial cells
(differentiated as lamellae) in 4--6 rows; transverse section circular,
adaxial epidermis apparently absent, adaxial stereid band absent, guide cells
2 in 1 layer, hydroid strand present, usually large, abaxial stereid band
present, often weak and round to elliptic in section, abaxial epidermis
present; proximal cells differentiated across leaf base, occasionally higher
medially, rectangular, little wider than the distal cells or somewhat
inflated, ca. 2--5:1, walls of basal cells thin; distal medial cells quadrate
to shortly rectangular, often transversely elongated, 10--13(--20) µm wide,
(2--)1:1(--2), 1-stratose; papillae absent or small, simple, solid or hollow
and present abaxially and medially, 2--3 per lumen, cell walls thin to weakly
thickened and weakly trigonous, flat or somewhat bulging on both sides or
just abaxially. Specialized asexual
reproduction absent. Sexual
condition autoicous or paroicous. Perichaetia
terminal, interior leaves not sheathing, elliptic, little differentiated, to
1.5 mm. Seta 0.4-3.5 mm. Capsule stegocarpous or rarely
cleistocarpous, theca short-cylindric, often macrostomous, variously smooth,
sulcate or ridged, 0.5--1.5 mm, annulus when present of ca. 3 rows somewhat
vesiculose cells; operculum rostrate to conic-rostrate; peristome teeth
absent or when present rudimentary, in a latticework borne on a membrane,
weakly twisted, teeth to 300 µm. Calyptra
cucullate or mitrate with 3--4 large lobes. Spores 25-38 µm. KOH
distal laminal color reaction yellow, occasionally red or orange in spots
medially near apex or at leaf base. Species 12 (4 in the flora): most
continents, dry climate, soil or occasionally rock. SELECTED REFERENCES Wareham, R. T.
1939. Pterigoneurum [sic]. In: A.
J. Grout, Moss Flora of North America North of Mexico.1(4): 208--211. Zander,
R. H. 1993. Genera of the Pottiaceae: Mosses of Harsh Environments. Bull. Buffalo
Soc. Nat. Sci.32. Pterygoneurum is apparently most closely related to Crossidium, and, like that genus, has
chlorophyllose filaments (occasionally) in addition to the adaxial costal
lamellae, and the stem is densely clothed with pale, brown rhizoids. Pterygoneurum is common in arid
regions of the West, forming a dense, low turf in exposed soil. The hyaline
awns and short setae are distinctive in the field. 1. Capsules immersed or partly exerted,
calyptra mitrate. 2.Lamellae ca. 4--12 cells high;
capsules immersed to somewhat exerted, stegocarpous (var. kieneri has an annulus but bursts
irregularly) . . . . 3. Pterygoneurum
subsessile 2.Lamellae often low, 2--6(--10) cells
high; capsules immersed, cleistocarpous. . . . . . 4. Pterygoneurum
kozlovii 1. Capsules exerted on an elongate
seta, calyptra cucullate or rarely mitrate. 3. Distal
lamina smooth or rarely abaxially papillose; lamellae even in shape and size;
capsules shortly exerted, ovoid; peristome lacking; cells of operculum in
straight rows . . . . . 2. Pterygoneurum
ovatum 3. Distal lamina often abaxially weakly
papillose; lamellae irregular in shape and size; capsules cylindric, long
exerted; peristome occasionally present, fragile; cells of operculum slightly
twisted . . . . . . 1. Pterygoneurum
lamellatum 1. Pterygoneurum lamellatum (Lindberg) Juratzka, Laubmfl. Oest.
Ungarn 97. 1882 Tortula
lamellata Lindberg,
Oefv. K. Vet. Ak. Foerh.21: 233. 1864; Pterygoneurum
arcticum Steere Leaves with distal lamina sometimes weakly papillose
abaxially; awn smooth; lamellae (0--)8--14 cells in height, irregularly
lobed, often bearing filaments. Capsule
stegocarpous, exerted, short- to long-cylindric, annulus present, operculum
cells in twisted rows; peristome present, fragile and often adherent to the
operculum. Calyptra cucullate. Capsules mature late winter, spring.
soil, rock faces; 500--1400 m; B.C., Nun.; Alaska, Ariz., Calif., Nev., Utah;
Europe; Asia. The operculum of P. lamellatum is commonly long-conic when dry, while that of P. ovatum is generally linear. The
peristome may be trellis-like (illustrated by S. Flowers (1973) or a
rudimentary arrangement of small plates over a membrane (R. H. Zander 1993:
202), or even absent. Also keying to P. lamellatum is the
British Columbian specimen reported by T. T. McIntosh (1989) as Tortula
wilsonii (Hooker) R. H. Zander. This proved to be a new species of Pterygoneurum
distinguished by broadly recurved leaf margins and multiple papillae on both
sides of the leaf above midleaf, these being unique traits for the genus. The
adaxial costal lamellae are distinct but occasionally absent in some plants,
which then phenocopy Tortula or Hilpertia. This specimen in
turn proved to be the same as a Pterygoneurum discussed but not
formally described by B. M. Murray (1992) for Alaska; a name will be provided
by her in a future publication. 2. Pterygoneurum ovatum (Hedwig) Dixon Gymnostomum ovatum Hedwig, Spec.
Musc.31. 1801; Pterygoneurum cavifolium
Juratzka, illegitimate name Leaves with distal lamina smooth or rarely
papilose; awn smooth or rarely with a few teeth; lamellae 8--16 cells in
height, not lobed, seldom bearing filaments. Capsule stegocarpous, emergent to exerted, ovoid, annulus
present, operculum cells in straight rows; eperistomate. Calyptra cucullate or rarely mitrate. Spores mature spring. soil (volcanic,
dry saline), frost boil, low desert scrub areas; 900--1520 m; Alta., B.C., Man.**s**,
N.W.T.**n**, Nun., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo.,
Idaho, Kans., Mont., Nebr., Nev., N.Mex., N.Dak., Oreg., S.Dak., Tex., Utah,
Wash., Wyo.; s South America, Europe, Asia, n Africa, Australia. R. T. Wareham (1939) found the
characters of var. incanum, long
awns and short setae, inconstant in both American and European material. This
is the most common species, and serves to stabilize arid soils (S. Flowers
1973). The setae may reach 3 mm. Faint thickenings reminiscent of a
rudimentary peristome can sometimes be found associated with spore sac
remnants dug out of the operculum, and the laminal distal cells may by simply
papillose abaxially as in P.
lamellatum. 3. Pterygoneurum subsessile (Bridel) Juratzka, Laubmfl. Oest.
Ungarn 96. 1882 Pterygoneurum
californicum H. A.
Crum; P. subsessile var. henrici (Rau) R. T. Wareham Leaves with distal lamina smooth; awn smooth
or sharply serrulate; lamellae 10--12 cells in height, not lobed, sometimes
bearing filaments. Capsules
stegocarpous (or stegocarpous but bursting irregularly), immersed to
emergent, short-ovoid, annulus present, operculum cells in straight rows;
eperistomate. Calyptra cucullate
or rarely mitrate. Varieties 2 (2 in the flora): North
Temperate Zone, s South America. This is an abundant moss in the arid
West, often occurring with P. ovatum.
In some specimens, the perigoniate plants appear separate, but this species
and doubtless others are apparently occasionally rhizautoicous. Following the
reasoning of R. T. Wareham's (1939) discussion, P. subsessile var. henrici
is placed with the typical variety. The characters associated (H. A. Crum
1967) with P. californicum are
poor: the spores are finely papillose, the leaf cells do have weak
collenchymatous thickenings, and the calyptra is long-mitrate. 1. Capsule dehiscent by the fallen
operculum . . . . . . . 3a. Pterygoneurum subsessile var. subsessile 1. Capsule bursting irregularly,
annulus differentiated but not fissile . . . . 3b. Pterygoneurum
subsessile var. kieneri 3a. Pterygoneurum subsessile var. subsessile Capsule stegocarpous, spores released after operculum
falls. Spores mature late winter, spring. soil
(sandy, volcanic), alkali flats; 600--1700 m; B.C., Alta., Sask., Yukon;
Alaska, Ariz., Calif., Colo., Idaho, Ill., Iowa., Kans., Minn., Nebr., Nev.,
N.Mex., N.Dak., Okla., Oreg., S.Dak., Tex., Utah, Wyo.; s South America,
Europe, Asia, n Africa. 3b. Pterygoneurum subsessile var. kieneri H. Habeeb, Rhodora 51: 128. 1949 Capsule facultatively cleistocarpous: annulus
differentiated but operculum remains attached, spores released through
ruptured capsule walls. Capsules mature July. Grassland soil;
950 m; Nebr. This taxon is P. subsessile with possibly hybrid sporophytes. Two forms with
identical gametophytes were present in the type collection, one with typical
sporophyte, the other with that of the variety. The operculum is not
dehiscent and the capsule bursts irregularly. The sporophyte apparently falls
as a unit, breaking off at the base of the seta. The single collection is
from Nebraska, Chase Co., 12.5 km W of Champion, W. Kiener 10627 (MO). 4. Pterygoneurum kozlovii Lazarenko, Bot. Žurn. Ak. Nauk Uk. RSS
3: 61. 1946 Leaves with distal lamina smooth; awn smooth
or sharply serrulate; lamellae 2--6(--10) cells in height, not lobed,
sometimes bearing filaments. Capsules cleistocarpous,
immersed to emergent, short-ovoid; eperistomate. Calyptra cucullate or rarely mitrate. Capsules mature spring. Grassy areas,
around alkaline depressions, steppe; moderate elevations; B.C.**s**, Sask.**s**;
c Europe. This locally abundant (T. T. McIntosh
1989) western species commonly grows in mixture with other species of the
genus; although the gametophyte is much the same as that of P. subsessile,
the brown, spheric cleistocarpous capsules with no annulus are unique.
Perigonia are borne terminally on short lateral or basal branches. OTHER REFERENCES Crum, H. A. 1967. A new species of Pterigoneurum [sic] from California.
Madroño 19: 92--94. Flowers, S. 1973. Mosses: Utah &
the West. Provo, Utah. McIntosh, T. T. 1986. The Bryophytes of
the Semi-Arid Steppe of South-Central British Columbia. Dissert., University
of British Columbia, Vancouver, B.C., Canada. 345 pp. McIntosh, T. T. 1989. Bryophyte records
from the semiarid steppe of northwestern North America, including four
species new to North America. Bryologist 92: 356--362. Murray, B. M. 1992. Bryophyte flora of
Alaskan steppes. Bryobrothera 1: 9--33.
Wareham, R. T. 1939. Pterigoneurum [sic]. In: A. J. Grout,
Moss Flora of North America North of Mexico. 1(4): 208--211. Newfane, Vt. |
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