Selaginella kraussiana

(Kunze) A. Braun

Index Seminum (Berlin) App. 22. 1860.

Common names: Mat spike-moss
Introduced
Basionym: Lycopodium kraussianum Kunze Linnaea 18: 114. 1844
Treatment appears in FNA Volume 2.

Plants terrestrial, forming diffuse mats. Stems long-creeping, branched, branches 3-forked, flat, articulate, glabrous. Rhizophores borne on upperside of stems throughout stem length, 1–3 mm diam. Leaves delicate, papery. Lateral leaves nearly perpendicular to stem, well spaced, green, lanceolate, 2.5–3.6 × 0.8–1.2 mm; base rounded; margins slightly transparent to green, dentate; apex acute. Median leaves lanceolate to linear-lanceolate, 2–2.7 × 0.6–0.8 mm; base with small outer auricle; margins slightly transparent to green, dentate; apex acuminate. Strobili solitary, 0.2–2.5 cm, with only 1 megasporangium, megasporangium basal; sporophylls keeled, dentate, strongly tapering toward apex, base glabrous, margins denticulate, apex acuminate; megasporophylls larger than microsporophylls, in groups of 4, 2 like vegetative leaves, 2 like sporophylls, of the latter 1 large, lanceolate-elliptic, 1 smaller, falcate-lanceolate; microsporophylls lanceolate to narrowly ovatelanceolate. 2n = 20.


Habitat: Moist areas, riverbanks, lake margins, lawns
Elevation: 0–50 m

Discussion

Selaginella kraussiana has escaped from cultivation and is naturalized in central Georgia, and probably farther south and west. It has been reported as far north as coastal central California and northern Virginia (D. B. Lellinger 1985), but I have not seen specimens from these areas. Selaginella kraussiana is frequently cultivated and has several cultivars. It is widely used in morphologic and anatomic research and for teaching purposes. This species belongs to the series Articulatae Spring, a very distinct group of heterophyllous selaginellas with rhizophores on the upper side of the stem, special microsporangium type and dehiscence (P. Somers 1982), basal megasporangia, the largest megaspores in the genus, mostly spiny microspores, and usually more than one meristele. These and other characteristics suggest that series Articulatae probably deserves subgeneric ranking.

Selected References

None.

Lower Taxa

None.
... more about "Selaginella kraussiana"
acuminate +  and acute +
Iván A. Valdespino +
(Kunze) A. Braun +
rounded +
Lycopodium kraussianum +
3-forked +
Mat spike-moss +
Ala. +  and Ga. +
0–50 m +
Moist areas, riverbanks, lake margins, lawns +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
ciliate +  and dentate +
arranged +  and overlapping +
2 (?) +  and 4 (?) +
slightly transparent +  and green +
denticulate +
diffuse +
0.2 cm2 mm <br />0.002 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
lanceolate;linear-lanceolate +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
globose +, ovoid +  and tetrahedral +
falcate-lanceolate +
smaller +  and larger +
tetrahedral +
Index Seminum (Berlin) +
alternating +
size +  and shape +
linear-lanceolate;ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Introduced +
adjacently +  and monomorphic +
vinelike +, climbing +  and cespitose +
flattened +  and quadrangular +
0.2 cm2 mm <br />0.002 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Selaginella kraussiana +
Selaginella subg. Stachygynandrum +
species +
articulate +  and branched +
not +, articulate +  and branched +
perennial +  and annual +
epiphytic +  and hemiepiphytic +
12 +, 11 +, 10 +, 9 +, 8 +  and 7 +