Lepidodendron rhodianum STERNB., 1825

Lepidodendron rhodianum STERNB., 1825

Text-fig. 4 View Text-fig

1823 “Schuppenpflanze”; Rhode, p. 7, pl. 1, figs 1, 3, 4.

1825 Lepidodendron rhodianum STERNB. , p. xi. (based on Rhode 1820: pl. 1, figs 1, 3)

1970 Lepidodendron rhodianum STERNB. ; Thomas, p. 169, text-fig. 12.

D e s c r i p t i o n. Stems with spirally-arranged, contiguous leaf cushions. Cushions more or less isodiametric, 3–4 mm in size, subrhomboidal to obovate, with an obtuse upper angle, an elongate, sinuous lower angle and rounded lateral angles. Rhomboidal leaf scar occurs in upper part of cushion, with lateral lines extending to upper margin of cushion and a keel below scar variable in length; infrafoliar parichnos clearly marked. Cushion surface smooth below scar, striate above the scar.

R e m a r k s. Several specimens of relatively slender branches in the Kidston Collection recorded as Lepidodendron rhodianum STERNB. were mentioned but not figured by Crookall (1964). Cuticles from another specimen from the Upper Limestone Formation were described by Thomas (1970). Relatively slender branches of L. rhodianum often occur in association with larger stems of L. veltheimii and it is possible that they represent parts of the same plant: smaller, more isodiametric cushions occur in the upper parts of the plant, larger, more elongate cushions in the upper part.

This species epithet is often given as rhodeanum, but in the protologue it is spelled rhodianum and so this is used here.

O c c u r r e n c e s. Known only from the Johnstone Shell

Bed (Limestone Coal Formation) and below the Orchard

Limestone (Upper Limestone Formation).