Rhizome short, 4-14 x 2-3.3 mm, ellipsoid to spindle-shaped, no persistent leaf bases present; roots descending, sometimes becoming horizontal. Leaves mid-green, up to 2 but mostly 1, held at c.75° from the horizontal. Petiole 1.8-3.7 cm long, subterranean for about half of its length, petiole:lamina lenght ratio ±1:1. Sterile lamina 14-39 × 2.5-5 mm, width:lenght ratio 4.8-9.5:1, very narrowly elliptic in outline, apex pointed, base gradually diminishing in breadth, venation linear or elongate, with a few included veinlets and secondary veins confined to the margin. Fertile lamina often concave above; fertile segment 3-6 cm long, petiole:lamina lenght ratio 1.9:1, inserted at or just above the base of the lamina. Sporangia 6-19 pairs.

O. gracillimum, O. lusoafricanum and O. sandiae are, like O. caroticaule, narrow leaved Ophioglossum species. The leaf width:length ratio of O. caroticaule (1:7.2) differs from O. gracillimum (1:10-20) and O. sandiae (1:4.5). O. lusoafricanum has a leaf width: length ratio of 1:7-9 and a slender, linear rhizome.

caroticaule: rhizome resembling a carrot.

Seasonally wet areas over sheetrock among scrub and short grasses along streams, shallow soils beneath seasonally dry deciduous woodland, sometimes in high altitude grassland.

See African distribution.

Ethiopia, Kenya, South Africa, Tanzania , Uganda, Zambia, Zimbabwe.

Lithophytic, terrestrial.