Hymenostylium recurvirostrum

(Hedwig) Dixon

Rev. Bryol. Lichénol., n. s. 6: 96. 1934,.

Basionym: Gymnostomum recurvirostrum Hedwig Sp. Musc. Frond., 33. 1801
Treatment appears in FNA Volume 27. Treatment on page 578. Mentioned on page 496, 522, 536, 537, 557, 558, 560, 564, 579.

Stems slender, fragile, 0.5–7 cm. Leaves more or less distant; costa ending 1–2 cells before apex to percurrent or short-excurrent as a flat to conical apiculus, occasionally ending in a pellucid cell, often scalloped along margins by projecting cell-walls, at mid leaf with 2–4 or occasionally several rows of cells across adaxial surface; costa adaxial surface U-shaped in section; basal-cells gradually differentiated, elongate-rectangular, less to nonpapillose proximally, larger than distal cells, 20-50 µm, 2–4: 1, walls firm, narrower on the margins, pellucid; distal laminal cells heterogeneous: subquadrate to shortrectangular or rhomboidal, with occasional diagonally transverse walls, longitudinally elongate especially distally near the costa, walls commonly irregularly thickened to porose, marginal cells smaller and more quadrate, ca. 7–10 (–12) µm wide, 1–3: 1, 1: 2, seldom 2-stratose in patches, cell-walls superficially flat to somewhat convex, firm-walled; papillae low, simple to 2-fid, 1–3 (–5) per lumen, dense to scattered, occasionally absent. Sexual condition perigonial terminal and often also lateral proximally. Seta single, (0.04–) 0.5–0.9 (–1) cm. Capsule urn 0.5–0.9 (–10) mm, often widest at the mouth when dry, exothecial cells thin to thick-walled, 1–4: 1, stomates phaneropore at base of capsule; annulus weakly vesiculose. Operculum ca. 0.5–1 mm, usually attached to the columella at least in some capsules. Calyptra ca. 1–1.5 mm. Spores ca. (13–) 17–20 (–22) µm.

Distribution

North America, Central America, South America, Europe, Asia, Africa, Atlantic Islands, Pacific Islands, Australasia

Discussion

Varieties 5 (2 in the flora).

Hymenostylium recurvirostrum is distinctive among similar species in having one laminal margin typically recurved, the other erect. A character often overlooked in texts is the universal presence of a long, narrow, fragile decurrency in the basal angles. Both Gymnostomum aeruginosum and Eucladium verticillatum have an adaxial epidermis in the costal section, with papillose and quadrate cells on the adaxial surface of the costa in plane view, and the costa profile is round (convex), but Hymenostylium has long, thin and smooth cells in plane view because the epidermal layer is not developed, and the costal profile is convex adaxially, being lunate in section. In Anoectangium aestivum, as in those two species, the dense laminal papillae often obscure cell lumens, but the leaf section shows a very deeply keeled leaf with the leaf lamina adjacent to the costa nearly contiguous or touching, showing a deep, narrow channel in plane view and a circular costa section. The adaxial stereid band is always absent in A. aestivum, but often present in H. recurvirostrum. Molendoa sendtneriana is similar but has a stem central strand, and lateral perichaetia (like A. aestivum).

Selected References

None.

Key

1 Leaves 1-1.6 mm, margins narrowly recurved proximally, rarely 2-stratose distally, base not differentiated in shape or ovate; stem hyalodermis variably absent or present, leaf cells mostly evenly thickened except along the costa; costa in section depauperate, adaxial stereids (0-)2-4 cells across, stem sclerodermis of (0-)1-2(-3) layers Hymenostylium recurvirostrum var. recurvirostrum
1 Leaves (1.6-)2-2.4 mm, margins broadly recurved proximally, often 2-stratose in patches distally, base rectangular, flaring, with shoulders; stem hyalodermis always present, leaf cells distinctly porose throughout or at the leaf base, especially along the costa; costa in section robust, adaxial stereids 6-8(-10) cells across; stem sclerodermis thick, of 3-5 layers Hymenostylium recurvirostrum var. insigne
smooth +  and papillose +
elongate +  and quadrate +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
of 1-2 rows +  and differentiated +
short-excurrent +  and percurrent +
flat +  and conical +
Patricia M. Eckel +
(Hedwig) Dixon +
reniform +  and rounded +
nonpapillose +
elongate-rectangular +
papillose +  and smooth +
usually slightly wider +
rectangular;ovate +
expanded +
differentiated +
Gymnostomum recurvirostrum +
obovoid +
cucullate +
0.1 cm1 mm <br />0.001 m <br /> (?) +  and 0.15 cm1.5 mm <br />0.0015 m <br /> (?) +
yellow +  and redbrown +
cleistocarpous +  and stegocarpous +
subcylindric;obovoid;subcylindric;obovoid;ovoid;globose +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
monoicous +, dioicous +  and sexual +
convex +  and flat to somewhat +
incrassate +
vesiculose +  and thick-walled +
1 (?) +  and 2 (?) +
elongate-rhomboid +  and elongate +
tomentose +  and bare +
scalloped +
smaller +
North America +, Central America +, South America +, Europe +, Asia +, Africa +, Atlantic Islands +, Pacific Islands +  and Australasia +
differentiated +
multicellular +
yellow +  and orange-red or red +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
concave;keeled;channeled;ovoid;lanceolate or lingulate +
linear +  and oblong-lanceolate +
reduced +
specialized +
dioicous +, sexual +  and asexual +
dentate +  and entire +
scalloped-denticulate +  and papillose-denticulate +
7um +  and 10um +
percurrent +  and excurrent +
conic-rostrate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
photosynthetic +
lateral +  and low +
1 +  and 3 +
small +  and extensive +
lateral +  and terminal +
lateral +  and terminal +
red +, orange +  and yellow +
consisting of 16 mostly 2 times cleft spiculose striate or papillose lanceolate teeth , , , , +  and rudimentary +
depauperate +
Rev. Bryol. Lichénol., n. s. +
straight +
0.9 cm9 mm <br />0.009 m <br /> (1 cm10 mm <br />0.01 m <br />) +
redbrown;yellow +
elongate +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
yellow +, laminal +  and brownish +
scabrous-papillose +  and smooth +
rounded-triangular +  and rounded-pentagonal +
slender +
0.5 cm5 mm <br />0.005 m <br /> (7 cm70 mm <br />0.07 m <br />) +
Hymenostylium recurvirostrum +
Hymenostylium +
species +
ovoid;cylindric +
occasional +
rhomboidal +
narrower +
stemless +  and perigoniate +
red tinge;yellow;dark green distally +
cushion +  and plant +
occasionally smaller than the perichaetiate +