The Lycopodiales of the British Isles (Isoetes, Lycopodium, Selaginella)
S. spinosa Beauv., S. spinulosa A. Br.
Morphology. Stems elongated, with numerous small leaves; creeping, and rooting from characteristic, leafless, root-bearing branches (rhizophores); 3–15 cm long (the decumbent, slender stems bearing short sterile and long fertile, ascending branches); overtly dichotomising vegetatively; not dorsiventrally organized; with non-flattened branches; without secondary thickening. Leaves ligulate; not 4-ranked; all alike and spirally arranged; 2–4 mm long; appressed to spreading.
Heterosporous. Sporophylls resembling the foliage leaves (but larger); aggregated into well defined terminal cones. Cones sessile at the tips of the normal shoots (1–1.5 cm long). The sporangia basal and subsessile on the adaxial surfaces of the sporophylls, non-septate.
Ecology and distribution. Mainly montane; on damp, mossy or peaty ground. Widespread and rather common on high ground in England, Scotland, Wales and Ireland, ascending to about 1000 m.
Classification. Family Selaginellacae.
Ilustrations. • S. selaginoides: Sowerby and Johnson (1859). • S. selaginoides: Eng. Bot. 1829 (1886). • British Lycopods: Sowerby and Johnson (1863).
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2007 onwards. The Lycopodiales of the British Isles (Isoetes, Lycopodium, Selaginella). Version: 1st September 2009. http://delta-intkey.com’.