Selaginella hansenii |
Selaginella mutica |
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Hansen's spike-moss |
bluntleaf spikemoss |
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Habit | Plants terrestrial, forming loose to clustered mats. | Plants on rock or terrestrial, forming loose mats. | ||||
Stems | not readily fragmenting, prostrate, upperside and underside structurally different, irregularly forked, branches determinate, tips upturned. |
radially symmetric, long- to short-creeping, not readily fragmenting, ± regularly forked, without budlike arrested branches, tips straight; main stem indeterminate, lateral branches determinate, 1–2-forked. |
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Leaves | with underside leaves slightly longer and narrower than upperside leaves, otherwise monomorphic, not clearly ranked, tightly appressed, ascending, green or green with red spots, or reddish, linear-lanceolate (underside) to linear-triangular (upperside), (2–)3–4.5 × 0.5–0.6 mm; abaxial ridges present; base abruptly adnate, pubescent (sometimes glabrous); margins ciliate, cilia white to white opaque, strongly appressed and ascending, 0.03–0.1 mm; apex with bristle white to white-opaque, 0.5–1.4 mm (those on underside leaves sometimes 1/4–1/2 longer than those on upperside leaves). |
monomorphic, in ± alternate pseudowhorls of 3, tightly appressed, ascending, green, lanceolate to linear-lanceolate or lanceolate-elliptic, 1–2 × 0.45–0.6 mm; abaxial ridges well defined; base rounded and adnate, sometimes slightly decurrent, pubescent or glabrous; margins ciliate to denticulate, cilia transparent, spreading or ascending, 0.03–0.17 mm; apex keeled, obtuse or slightly attenuate, nearly truncate in profile, blunt to short-bristled; bristle transparent to greenish transparent or whitish, smooth, 0.06–0.45 mm. |
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Strobili | solitary, 5–7 mm; sporophylls ovate-deltate to ovate-triangular, abaxial ridges not prominent, base glabrous, margins short-ciliate, apex bristled. |
solitary, (0.6–)1–3 cm; sporophylls ovate-lanceolate, ovate-elliptic, or deltate-ovate, abaxial ridges well defined, base glabrous, margins ciliate to denticulate, apex strongly to slightly keeled, short-bristled to blunt. |
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Rhizophores | borne on upperside of stems, throughout stem length, 0.25–0.45 mm diam. |
borne on upperside of stems, throughout stem length, 0.13–0.23 mm diam. |
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2n | = 18. |
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Selaginella hansenii |
Selaginella mutica |
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Habitat | Cliffs and rocky slopes or on igneous rock | |||||
Elevation | 330–1350 m (1100–4400 ft) | |||||
Distribution |
CA
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AZ; CO; NM; TX; UT; WY; only in the flora
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Discussion | Leaf dimorphism in Selaginella hansenii is only slightly and inconsistently expressed; the upperside leaves tend to be more lanceolate, short, and slightly thick, whereas the underside leaves tend to be more linear, longer, and thinner, but in some specimens the leaves are monomorphic. Red leaves are rare within Selaginella subg. Tetragonostachys, otherwise found in the flora only occasionally in S. rupestris. Such leaves are more common in S. steyermarkii Alston from southern Mexico and Guatemala and S. sartorii Hieronymus from Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Selaginella mutica, S. underwoodii (R. M. Tryon 1955; C. A. Weatherby 1943), and S. wallacei all have similar patterns of variation. Study is needed to assess to what degree such variability is caused by environmental or genetic factors. Within S. mutica, two rather distinct, morphologic extremes are recognized here as varieties. Many specimens having leaves with spreading, long, marginal cilia and a short, broken, apical bristle have been considered intermediate between the two varieties, but they belong in S. mutica var. mutica. Selaginella mutica may be one of the parent species of the putative hybrid species S. × neomexicana (see discussion). Selaginella mutica is often found growing in the same habitat with S. underwoodii, S. × neomexicana, and S. weatherbiana. According to R. M. Tryon (1955), where the two grow together, S. mutica mats gradually entirely replace mats of S. underwoodii over time. Selaginella mutica is sometimes confused with S. viridissima. Varieties 2. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 2. | FNA vol. 2. | ||||
Parent taxa | Selaginellaceae > Selaginella > subg. Tetragonostachys | Selaginellaceae > Selaginella > subg. Tetragonostachys | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Hieronymus: Hedwigia 39: 301. (1900) | D. C. Eaton ex L. Underwood: Bull. Torrey Bot. Club 25: 128. (1898) | ||||
Web links |