Selaginella rupestris

(Linnaeus) Spring

Flora 21: 182. 1838.

Common names: Rock spike-moss dwarf spike-moss sélaginelle des rochers sélaginelle rupestre
IllustratedEndemic
Basionym: Lycopodium rupestris Linnaeus Sp. Pl. 2: 1101. 1753
Treatment appears in FNA Volume 2.

Plants on rock or terrestrial, forming long or spreading mats or rarely cushionlike mats. Stems radially symmetric, long to moderately short-creeping to decumbent, not readily fragmenting, irregularly forked, without budlike arrested branches, tips straight; main-stem indeterminate, lateral branches conspicuously or inconspicuously determinate, sometimes ascending, 1–3-forked. Rhizophores borne on upperside of stems, throughout stem length, 0.25–0.45 mm diam. Leaves monomorphic, in alternate pseudowhorls of 6 (on main-stem) to 4 (on lateral branches), tightly appressed, ascending, green, occasionally reddish, linear or linear-lanceolate, 2.5–4 (–4.5) X 0.45–0.6 mm; abaxial ridges well defined; base cuneate and decurrent on underside to rounded and adnate on upperside, pubescent or glabrous; margins long-ciliate, cilia transparent, spreading, (0.05–) 0.07–0.17 mm; apex slightly keeled, mostly attenuate; bristle white, whitish, or transparent, puberulent, 0.45–1 (–1.5) mm. Strobili solitary, 0.5–3.5 cm; sporophylls deltate-ovate to ovatelanceolate, strongly tapering or not toward apex, abaxial ridges well defined, base glabrous, margins ciliate to slightly dentate, apex slightly keeled, not truncate in profile, long-bristled. 2n = 18.


Habitat: Dry ledges, sea cliffs, limestone, open fire-barrens, sandstone, granite outcrops, exposed rock, rock crevices, sandy or gravelly soil or grassy meadows
Elevation: 0–1900 m

Distribution

V2 394-distribution-map.gif

Greenland, Alta., Man., N.B., N.S., Ont., Que., Sask., Ala., Ark., Conn., Del., Ga., Ill., Ind., Iowa., Ky., Kans., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio., Okla., Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis., Wyo.

Discussion

Selaginella rupestris has the widest range of any selaginella in the flora. It is variable in many characteristics, e.g., the hairiness of the margins (which sometimes are not hairy), leaf base pubescence, and shape of sporophylls. The variation in sporangial distribution pattern in the strobili and the number of megaspores per megasporangium are important for understanding reproduction and relationships in this species. Very often the strobili are wholly megasporangiate, with only 1–2 megaspores per megasporangium, suggesting asexual reproduction. In other cases, both types of sporangia are present in a strobilus, suggesting sexual reproduction. R. M. Tryon (1971) correlated sporangial and spore distribution patterns in S. rupestris with distributional ranges and concluded that there are four races. Race A has 4 megaspores per megasporangium, has microsporangia, is sexual, and is distributed from southeastern Pennsylvania south to Georgia and Alabama. Race B has 1–2(–4) megaspores per megasporangium, has microsporangia, has an unknown type of reproduction, and has the same range as Race A, but it extends into New York. Race C has 1–2 megaspores per megasporangium, has microsporangia, is probably asexual, and is distributed throughout the species range. Race D has 1–2 megaspores per megasporangium, lacks microsporangia, is therefore asexual, and is found throughout the species range except where Race A occurs. These patterns suggest the presence of more than one species within S. rupestris in the broad sense. More studies, especially cytologic, are needed, as well as fieldwork, in order to understand these relationships and the variability in S. rupestris. Among the species in the flora, S. rupestris seems to be most closely related to S. sibirica (see discussion) and may also be allied to the S. arenicola complex (see discussion).

Selected References

None.

Lower Taxa

None.
... more about "Selaginella rupestris"
Iván A. Valdespino +
(Linnaeus) Spring +
glabrous +  and pubescent +
decurrent +  and cuneate +
Lycopodium rupestris +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
transparent;whitish;transparent;whitish;white +
0.045 cm0.45 mm <br />4.5e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.007 cm0.07 mm <br />7.0e-5 m <br />) +
transparent +
0.007 cm0.07 mm <br />7.0e-5 m <br /> (0.017 cm0.17 mm <br />1.7e-4 m <br />) +
Rock spike-moss +, dwarf spike-moss +, sélaginelle des rochers +  and sélaginelle rupestre +
Greenland +, Alta. +, Man. +, N.B. +, N.S. +, Ont. +, Que. +, Sask. +, Ala. +, Ark. +, Conn. +, Del. +, Ga. +, Ill. +, Ind. +, Iowa. +, Ky. +, Kans. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio. +, Okla. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Vt. +, Va. +, W.Va. +, Wis. +  and Wyo. +
0–1900 m +
Dry ledges, sea cliffs, limestone, open fire-barrens, sandstone, granite outcrops, exposed rock, rock crevices, sandy or gravelly soil or grassy meadows +
monomorphic +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
reddish +  and green +
2.5mm;4mm +
fertile +  and vegetative +
linear-lanceolate;linear +
0.045 cm0.45 mm <br />4.5e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
ciliate +  and serrate +
ciliate to slightly +
cushionlike +
globose +, ovoid +  and tetrahedral +
tetrahedral +
alternating +
0.025 cm0.25 mm <br />2.5e-4 m <br /> (0.045 cm0.45 mm <br />4.5e-4 m <br />) +
Illustrated +  and Endemic +
adjacently +  and monomorphic +
fertile +  and vegetative +
branched +, not +  and articulate +
dimorphic +, climbing +  and cespitose +
moderately short-creeping;decumbent +
quadrangular +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Selaginella rupestris +
Selaginella subg. Tetragonostachys +
species +
straight +
branched +  and not articulate +
erect +  and creeping +
branched +  and not articulate +
erect +  and creeping +
differentiated +
perennial +  and annual +
epiphytic +  and hemiepiphytic +
12 +, 11 +, 10 +, 9 +, 8 +  and 7 +