Pseudocrossidium hornschuchianum

(Schultz) R. H. Zander

Phytologia 44: 205. 1979,.

Basionym: Barbula hornschuchiana Schultz in C. F. Hornschuch, Syll. Pl. Nov. 1: 35. 1822
Treatment appears in FNA Volume 27. Treatment on page 572. Mentioned on page 566, 570.

Stems to 0.5 cm. Stem-leaves ovate-deltoid to short-lanceolate, 1–1.5 mm, distal margins once to almost twice-revolute; apex narrowly acute below the awn; costa ending in the long mucro or short awn, adaxial surface of costa at mid leaf convex, with 2–3 guide cells; distal laminal cells 10–13 µm wide, 1: 1. Specialized asexual reproduction absent. Perichaetial leaves strongly differentiated. Seta ca. 1 cm. Capsule ca. 1.7 mm, peristome of 32 linear, yellow teeth, twisted counterclockwise a half turn, operculum conic. Spores yellow, essentially smooth, 8–10 µm.


Habitat: Thin soil, lawns, limestone, bluff overlook, gardens, rock outcrop, ridge top
Elevation: low to moderate elevations (20-700 m)

Distribution

V27 821-distribution-map.gif

B.C., Mass., Oreg., Eurasia, Africa, Australia

Discussion

Pseudocrossidium hornschuchianum was first reported for North America from British Columbia by B. C. Tan et al. (1981), then from Massachusetts by B. D. Mishler and N. G. Miller (1983), apparently associated with ornamental cultivation. The Oregon station (Jackson County, Ferris Gulch, D. H. Wagner 9183, MO) is apparently, however, in a natural setting on a ridge top. This species differs from P. obtusulum by the narrowly acute apex with a long apiculus or short awn, and the strongly differentiated perichaetial leaves. Both perigoniate and archegoniate plants are present in the West (British Columbia), though at different sites, and the Oregon specimen was fruiting, while only perichaetiate plants are found in the East (Massachusetts).

Selected References

None.

Lower Taxa

None.
quadrate +  and shortly rectangular +
of 1-2 rows +  and differentiated +
long-excurrent +  and short-excurrent +
Richard H. Zander +
(Schultz) R. H. Zander +
reniform +  and rounded +
papillose +  and smooth +
usually slightly wider +
oblong;differentiated +
Barbula hornschuchiana +
obovoid +
cucullate +
stegocarpous +
1.7 cm17 mm <br />0.017 m <br /> (?) +
dioicous +  and sexual +
weakly convex +  and bulging +
vesiculose +, thin-walled +  and walled +
2 +  and 3 +
hollow-papillose +
elongate-rhomboid +  and elongate +
thicker +
tomentose +  and bare +
swollen +
denticulate +  and entire +
subquadrate;subquadrate +
B.C. +, Mass. +, Oreg. +, Eurasia +, Africa +  and Australia +
low to moderate elevations (20-700 m) +
differentiated +
multicellular +
2 +  and 3 +
Thin soil, lawns, limestone, bluff overlook, gardens, rock outcrop, ridge top +
awned +  and convolute-sheathing +
yellow +  and orange-red or red +
1 +  and 2 +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
ovate-deltoid;short-lanceolate +
usually broadly lanceolate +  and narrowly elliptical +
reduced +
dentate +  and entire +
photosynthetic +
photosynthetic +
multiplex +, 2-fid +  and plate-like +
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 +
1 (?) +, 2 (?) +  and 6 (?) +
straight +
elongate +
1 cm10 mm <br />0.01 m <br /> (?) +
2 +  and 1 +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
rounded-triangular +  and rounded-pentagonal +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Barbula sect. Platyneuron +, Barbula sect. Revolutae +  and Barbula subsect. Revolutae +
Pseudocrossidium hornschuchianum +
Pseudocrossidium +
species +
elliptic;cylindric +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
orange +  and hyaline +
thin +  and evenly thickened +
stemless +  and perigoniate +
yellowish green;brown distally +
occasionally smaller than the perichaetiate +