Selaginella standleyi

Maxon

Smithsonian Misc. Collect. 72: 9. 1920.

Common names: Standley's spike-moss
Synonyms: Selaginella densa var. standleyi (Maxon) R. M. Tryon
Treatment appears in FNA Volume 2.

Plants terrestrial or on rock, forming cushionlike or rather short, loose mats. Stems decumbent to short-creeping, not readily fragmenting, irregularly forked, without budlike arrested branches, tips straight; main-stem upperside and underside structurally slightly different, inconspicuously indeterminate, lateral branches radially symmetric, determinate, strongly ascending, 1-forked. Rhizophores borne on upperside of stems throughout stem length, 0.2–0.35 mm diam. Leaves monomorphic, in poorly defined pseudowhorls of 5 or 6, tightly appressed, ascending, green, linear, linear-oblong or linear-lanceolate, (2.5–) 3–4.5 mm (smaller on upperside leaves and in ascending buds); abaxial ridges present; base decurrent, oblique, glabrous or rarely pubescent; margins short-ciliate to denticulate, cilia transparent, scattered, spreading to ascending, 0.05–0.07 (–0.1) mm; apex keeled, obtuse, rather abruptly bristled; bristle usually yellowish or transparent to opaque, slightly puberulent or smooth, (0.4–) 0.7–1.25 mm. Strobili solitary, 0.5–1 (–2.3) cm; sporophylls deltate-ovate, rarely ovatelanceolate, abaxial ridges well defined, base glabrous, margins short-ciliate to denticulate on distal 3/4, apex keeled, strongly truncate in profile, abruptly bristled.


Habitat: Rock crevices, granitic outcrops, gravelly soil, bare soil, or alpine meadows
Elevation: 2000–3700 m

Distribution

V2 461-distribution-map.gif

Alta., B.C., Alaska, Colo., Mont., Wyo.

Discussion

R. M. Tryon (1955) reported an elevation range of 1500–4660 m for Selaginella standleyi. I have not seen specimens from these lower and higher elevations.

Selaginella standleyi is a member of the S. densa complex. It has sometimes been confused with S. watsonii and S. sibirica; it is, however, rather easy to distinguish by leaf and strobilus characters.

Selected References

None.

Lower Taxa

None.

"thick" is not a number.

... more about "Selaginella standleyi"
Bristled (?) +, Keeled (?) +  and Obtuse (?) +
Iván A. Valdespino +
glabrous +  and pubescent +
decurrent +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
transparent;opaque +
smooth +  and puberulent +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.125 cm1.25 mm <br />0.00125 m <br />) +
0.007 cm0.07 mm <br />7.0e-5 m <br /> (0.01 cm0.1 mm <br />1.0e-4 m <br />) +
transparent +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.007 cm0.07 mm <br />7.0e-5 m <br />) +
Standley's spike-moss +
Alta. +, B.C. +, Alaska +, Colo. +, Mont. +  and Wyo. +
2000–3700 m +
Rock crevices, granitic outcrops, gravelly soil, bare soil, or alpine meadows +
monomorphic +
fertile +  and vegetative +
linear-lanceolate;linear +
ciliate +  and serrate +
short-ciliate;denticulate +
cushionlike +
globose +, ovoid +  and tetrahedral +
tetrahedral +
Smithsonian Misc. Collect. +
alternating +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.035 cm0.35 mm <br />3.5e-4 m <br />) +
adjacently +  and monomorphic +
fertile +  and vegetative +
branched +, not +  and articulate +
dimorphic +, climbing +  and cespitose +
decumbent;short-creeping +
1 cm10 mm <br />0.01 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
quadrangular +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Selaginella densa var. standleyi +
Selaginella standleyi +
Selaginella subg. Tetragonostachys +
species +
straight +
branched +  and not articulate +
erect +  and creeping +
branched +  and not articulate +
erect +  and creeping +
differentiated +
perennial +  and annual +
on rock +  and terrestrial +
epiphytic +  and hemiepiphytic +
12 +, 11 +, 10 +, 9 +, 8 +  and 7 +