Fig. 6.

SEM images of seedlings of Trithuria austinensis. (A) A seedling with very long hypocotyl; close examination of this seedling revealed the presence of collar rhizoids, but they are not clearly visible at this magnification. (B) The same seedling as in (A), detail from another angle showing sheathing structure. (C) Seedling with short hypocotyl and long collar rhizoids. (D) Seedling with short, but clearly visible hypocotyl and long collar rhizoids. (E) Seedling with short hypocotyl and inconspicuous collar rhizoids; close examination revealed that the collar rhizoids are present but rare and much shorter than in (A − D). Labels: col, collar; cr, collar rhizoids; fol1, first foliage leaf; hyp, hypocotyl; mrt, main root; op, operculum; per, pericarp; sbr, shoot-borne root; sc, seed coat; ss, sheathing structure. Scale bars: A = 2 mm; B − D = 500 µm; E = 400 µm.