Eotrichocolea R.M.Schust.
Eotrichocolea R.M.Schust., J. Hattori Bot. Lab. 26: 252. 1963.
Type: Eotrichocolea polyacantha (Hook.f. & Taylor) R.M. Schust. (≡Jungermannia polyacantha Hook.f. & Taylor)
Plants ± prickly in appearance, anisophyllous, rather rigid, rather closely procumbent to ascending, light yellow-green, small, usually to only 2 cm long. Branching typically 1-pinnate (sporadically 2-pinnate), the branches irregularly arranged, nearly all of Frullania type, of limited length, cernuous, tapered, ultimately becoming flagelliform and microphyllous; Acromastigum -type branches rare. Stem rather large for plant size and notably more robust than the branch axes, paraphyllose, the paraphyllia 2–3(4)-celled, the cortical cells thin-walled, the medullary cells of similar size, also thin-walled. Leaves obliquely spreading, distant to contiguous, ± transverse to weakly to distinctly incubous, ± symmetrical, ca. 600–700 µm wide × 600–800 µm long, deeply quadrifid (lateral lobes slightly to markedly smaller), the lobes 2–4 cells wide at base, terminating in tapered cilia each comprised of a uniseriate row of 3–5 cells; margins of lobes with (1)2–5 cilia arranged alternately or (often) opposed, the armature often displaced and inserted on the abaxial surface of lobe and stiffly abaxially patent, the lateral cilia rather rigid, spiniform, tapered as in lobes, consisting of a uniseriate row of 2–3(4) cells; disc 2–3(4) cells high, the margins with short cilia. Cells moderately elongated (to 2:1 in disc, to 6:1 in lobes), with walls thin to somewhat firm, the surface of lobes conspicuously papillose, of disc distinctly and closely striolate-papillose. Oil-bodies pale smokey grey, the paired cells at base of uniseriate row of the lobes with 5–9 per cell, the uniseriate row with 8–12 per cell, the basal row of disc with 4–5 per cell, 6–7(9) per cell of next row up in the disc, the oil-bodies coarsely granular-papillose, the granules well defined, not protruding beyond the membrane, the oil-bodies subglobose, almost spherical but slightly distorted, ovoid, the larger ones less spherical and 7 × 10 µm, the spherical ones 6–7 µm in diam. Underleaves ca. 0.5× leaf size, deeply bifid, the lobes 2–3(4) cells wide at base, terminating in a uniseriate row of 3–4 cells, the lobes with a few, often opposed, marginal cilia similar to those of leaves and like them often abaxially displaced, the cilia at times with a marginal sessile slime papilla; disc 1–2 cells high. Asexual reproduction absent.
Dioecious. Androecia on main shoot, becoming intercalary; bracts not much differentiated from leaves, the disc somewhat concave; antheridia 1 per bract, the stalk short, biseriate. Gynoecia terminal on leading shoots; bracts leaf-like, inserted near coelocaule base as well as just beyond the coelocaule midpoint. Coelocaule clavate, the wall polystratose, bearing the bracts and variable paraphyllia, but with much of coelocaule surface exposed; perianth lacking, at times several larger, ciliate leaves are present near coelocaule apex, which may represent perianth vestiges; free calyptra absent, the unfertilized archegonia at coelocaule summit.
Foot massive, conoidal. Seta long, rather massive, becoming hollow at maturity. Capsule short-ellipsoidal, dehiscence irregular, the valves irregular in size and shape and tending to fragment with age, the wall 4–5-stratose; outer layer of cells large, hyaline, without pigmented thickenings; innermost layer of cells with complete or incomplete semiannular bands.
Spores and elaters unknown.
Eotrichocolea is monotypic. It differs from Trichocolea in general aspect, as well as several other features that include the incubous leaves, the irregular capsule dehiscence, the 4–5- layered (vs. [5]6–8-layered) capsule wall, and the sporadic ability to develop Acromastigum -type branches. The presence of drooping, tapered and ultimately flagelliform terminal branches is also distinctive vs. branches that spread ± in the same plane as the main shoot and that do not taper or become flagelliform toward the tips. Also, the ecology of Eotrichocolea is quite different, often occurring sparingly as isolated plants.
References: Schuster (2000a, 2001d).
