Selaginella scopulorum |
Selaginella wrightii |
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cliff selaginella, cliff spikemoss, compact spikemoss, Rocky Mountain spike-moss |
Wright's spike-moss |
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Habit | Plants terrestrial or on rock, forming cushionlike or rather loose mats. | Plants on rock, forming loose to dense mats. |
Stems | decumbent or creeping, not readily fragmenting, irregularly forked, without budlike arrested branches, tips straight; main stem upperside and underside structurally slightly different, conspicuously or inconspicuously indeterminate, lateral branches radially symmetric, conspicuously determinate, strongly ascending, 1–2-forked. |
not readily fragmenting, prostrate, upperside and underside structurally different, irregularly forked, branches determinate, tips upturned. |
Leaves | monomorphic, in poorly defined pseudowhorls of 4 or 6, tightly appressed, ascending, green, linear-lanceolate to linear, in lateral ranks sometimes falcate, 2.5–4(–4.3) X 0.5–0.75 mm (upperside leaves smaller than underside, smaller also on ascending buds); abaxial ridges present; base (on main stem) decurrent, oblique, and glabrous on underside leaves, slightly decurrent to adnate, oblique, and glabrous or rarely puberulent on upperside leaves; margins usually short-ciliate, cilia transparent, spreading or ascending at base, denticulate and ascending on distal 2/3, 0.02–0.07(–0.15) mm; apex plane or sometimes slightly keeled, obtuse to attenuate, abruptly bristled; bristle whitish, transparent to opaque, with few teeth or smooth, 0.5–1.1 mm. |
dimorphic, arranged in 8 ranks, tightly appressed, ascending, green; abaxial ridges absent; apex with yellowish bristle 0.2–0.5 mm, becoming denticulate (by breaking off of bristle); bristle usually more persistent in underside leaves. |
Strobili | solitary, (0.5–)1–3(–4.5) cm; sporophylls ovate-lanceolate, lanceolate, or seldom ovate, usually tapering toward apex, abaxial ridges well defined, base glabrous, margins proximally short-ciliate to denticulate, lacking cilia apically, apex usually attenuate or slightly keeled, short-bristled. |
solitary, (0.7–)1.5–2(–2.6) cm; sporophylls lanceolate, abaxial ridges not prominent, base glabrous, margins ciliate, apex strongly tapering, bristle obscure. |
Rhizophores | borne on upperside of stems, throughout stem length, 0.25–0.45 mm diam. |
borne on upperside of stems, throughout stem length, 0.25–0.37 mm diam. |
Underside | leaves narrowly linear-lanceolate to falcate (on marginal ranks), 3.5–4.5(–5) X 0.55–0.7 mm; base abruptly adnate or slightly decurrent, usually pubescent, sometimes glabrous; margins ciliate, cilia transparent, spreading, 0.12–0.26 mm. |
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Upperside | leaves linear-lanceolate, 3.3–3.85 × 0.6–0.75 mm; base abruptly adnate, pubescent; margins ciliate, cilia transparent, spreading, 0.12–0.26 mm. |
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Selaginella scopulorum |
Selaginella wrightii |
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Habitat | Rocky alpine tundra, subalpine meadows, dry cliffs, rocky slopes, rock crevices, granitic outcrops and ledges, sandstone outcrops, in soil pockets among rocks, or sandy or granitic soil | On exposed or shaded limestone cliffs |
Elevation | 700–3700 m (2300–12100 ft) | 800–2300 m (2600–7500 ft) |
Distribution |
AZ; CA; CO; ID; MT; NM; OR; UT; WA; WY; AB; BC
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NM; TX; Mexico |
Discussion | Selaginella scopulorum is a member of the S. densa complex, in which there is a clear need for more systematic studies. Some specimens of S. scopulorum from Montana, Wyoming, and Colorado have more conspicuous whitish bristles than those elsewhere and are difficult to distinguish from S. densa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of other species in the flora, Selaginella wrightii seems to be allied to S. hansenii. The structural differentiation of the stem, adjacently different leaves, and upturned branch tips align the two species to the series Eremophilae. Selaginella wrightii is a calciphile, according to R. M. Tryon (1955). Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Selaginellaceae > Selaginella > subg. Tetragonostachys | Selaginellaceae > Selaginella > subg. Tetragonostachys |
Sibling taxa | ||
Synonyms | S. densa var. scopulorum, S. engelmannii var. scopulorum | |
Name authority | Maxon: Amer. Fern J. 11: 36. (1921) | Hieronymus: Hedwigia 39: 298. (1900) |
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