Taxiphyllum alternans

(Cardot) Z. Iwatsuki

J. Hattori Bot. Lab. 26: 67. 1963.

Basionym: Isopterygium alternans Cardot Beih. Bot. Centralbl. 17: 37, fig. 23. 1904
Treatment appears in FNA Volume 28. Treatment on page 568. Mentioned on page 567.

Plants in thin mats, light to yellowish green or yellowish-brown. Stems 6 cm, 3–5 mm wide, complanate-foliate; sometimes radiculose ventrally. Leaves spreading, distant, becoming close and loosely imbricate at stem apices, ovate to broadly ovatelanceolate, symmetric or asymmetric, somewhat concave or flat, 1.5–3.5 × 0.8–1.6 mm; margins plane or rarely narrowly recurved just beyond base, serrulate to entire; apex acuminate to filiform-acuminate, frequently twisted; costa double, short, one branch often 1/3–1/2 leaf length, rarely ecostate; alar cells few, quadrate to long-rectangular, 14–43 × 14–20 µm, in 1–3+ rows, 2–5 cells in marginal row; laminal cells smooth; medial cells 84–156 × 9–12 µm. Sporophytes unknown.


Habitat: Soil, humus, exposed tree roots, rotten wood, logs in swamps, calcareous boulders beside streams and waterfalls
Elevation: low to moderate elevations (0-500 m)

Distribution

V28 886-distribution-map.gif

Ala., Fla., La., Md., N.C., S.C., Asia

Discussion

Taxiphyllum alternans is rare in North America. The species is recognized by leaves that are distant, ovate to broadly ovate-lanceolate with acuminate to filiform-acuminate, frequently twisted apices, plane margins, and 2–5 quadrate to short-rectangular cells in marginal rows. The species occurs in a few localities in the southeastern United States with disjunct occurrences in Maryland (Charles and Montgomery counties). This species has sometimes been confused with Plagiothecium cavifolium (Bridel) Z. Iwatsuki, but all Taxiphyllum species differ from Plagiothecium microscopically by their nondecurrent leaves and the presence of foliose pseudoparaphyllia.

Selected References

None.

Lower Taxa

None.
... more about "Taxiphyllum alternans"
acuminate;filiform-acuminate +
Robert R. Ireland Jr. +
(Cardot) Z. Iwatsuki +
not decurrent +
Isopterygium alternans +
erect;widespreading or squarrose +
oblong-ovate +, oblong-lanceolate +, ovatelanceolate +  and ovate +
cucullate +
straight +  and arcuate +
oblong-ovoid +
constricted +
similar +  and pigmented +
quadrate;long-rectangular +
enlarged +
differentiated +
14um +  and 20um +
same length +  and shorter than +
rudimentary +
ecostate +  and obscure +
sterile +, dioicous +, sexual +  and asexual +
Ala. +, Fla. +, La. +, Md. +, N.C. +, S.C. +  and Asia +
low to moderate elevations (0-500 m) +
fused +  and free +
filamentous +
Soil, humus, exposed tree roots, rotten wood, logs in swamps, calcareous boulders beside streams and waterfalls +
asymmetric +  and symmetric +
imbricate +, close +  and distant +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
flat +, concave +, ovate +  and broadly ovatelanceolate +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
serrulate +  and entire +
dioicous +, autoicous +  and sexual +
lanceolate;ovatelanceolate +
J. Hattori Bot. Lab. +
papillose +  and smooth +
yellowish +  and red +
elongate +
globose;ovoid +
complanate-foliate +
subjulaceous +  and julaceous +
falcate-secund +
straight +
erect +  and widespreading or squarrose +
oblong-ovate +, oblong-lanceolate +, ovatelanceolate +  and ovate +
6 cm60 mm <br />0.06 m <br /> (?) +
differentiated +
3mm;5mm +
Plagiothecium subg. Taxiphyllum +
Taxiphyllum alternans +
Taxiphyllum +
species +
light +  and yellowish green or yellowish-brown +
medium-sized;large +