| | The Lycopodiales of Britain and Ireland (Diphasiastrum, Huperzia, Isoetes, Lycopodium, Selaginella) |
Morphology. Stems elongated, with numerous small leaves; creeping, and rooting from characteristic, leafless, root-bearing branches (rhizophores); overtly dichotomising vegetatively; dorsiventrally organized, with four ranks of leaves (with two rows of leaves dorsally, and a row of larger leaves down each side); with strongly flattened branches; without secondary thickening. Leaves ligulate; 4-ranked on the branches; of two kinds: those of the two ranks on the upper side of the stem appressed and directed towards the stem apex, and those of the two lower ranks larger and spreading laterally; about 1 mm long (on the upper side of the stem), or 2 mm long (on the sides); appressed and spreading.
Heterosporous. Sporophylls ovate, cuspidate, keeled; aggregated into well defined terminal cones. Cones sessile at the tips of the normal shoots (short, 4-sided). The sporangia basal and subsessile on the adaxial surfaces of the sporophylls, non-septate.
Ecology and distribution. Commonly grown in greenhouses, naturalized in Cornwall, Ireland and perhaps elsewhere.
Classification. Family Selaginellacae.
Ilustrations. • Habit. • Stem anatomy. • S. aff. krausiana, shoot and sporangia. From Le Maout and Decaisne (1873).
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Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2007 onwards. The Lycopodiales of Britain and Ireland (Diphasiastrum, Huperzia, Isoetes, Lycopodium, Selaginella). Version: 5th August 2019. delta-intkey.com’.
