Trichocolea hatcheri E.A.Hodgs.
Trichocolea hatcheri E.A.Hodgs., Trans. Roy. Soc. New Zealand, Bot. 3: 69. 1965.
Holotype: New Zealand, North Is., Roto-Kui Bush, east of Taupo, 1934, Allison 7558 (MPN ex herb. Hodgson 7558, non vidi).
Trichocolea novaezelandiae R.M.Schust., J. Hattori Bot. Lab. 26: 265. 1963, sin. descr. lat.
Plants closely prostrate to adnate, compact and densely interwoven, deep green, velvety, small, 1–1.6 cm wide, including branches. Branches regularly 2-pinnate, tertiary branches rare, the leading axis retaining its dominance; branches julaceous, with a woolly appearance, with all sides appearing as a mass of interwoven cilia. Stems stiff, paraphyllia few or altogether lacking. Rhizoids usually absent, when present, long for plant size. Leaves of stem widely spreading but with lobes and cilia broadly arching toward shoot apex, the leaf thus somewhat hand-like, the leaves in situ often appearing as a dense fringe of cilia, the individual lobes often quite discernable, the leaves on the stem distant to approximate, becoming imbricate on branches, semiamplexicaul, the insertion transverse to weakly succubous, suborbicular to subreniform, 500–650 µm wide, 300–500 µm long, divided into 4–5 erect, pinnulate lobes (the lobes in ventral sector of leaf weakly larger), each lobe actually unequally (2)3-fid, consisting of a stronger, erect, pinnulate division and 1–2 small, irregularly branched, abaxially displaced, accessory divisions that are (1)2(3) cells wide at the base and feebly to distinctly arched in same direction as main lobes, the divisions armed with pairs of opposing branched cilia. Lobes caudate, somewhat irregularly pinnulate (best seen in adaxial view), with numerous segments and cilia, the ventral lobes 2–4 cells wide at base, with 2 tiers of laterally juxtaposed cells basal to the uniseriate row of 5–6 cells; cells of uniseriate row ± tapering, rather thin-walled, with only slightly thickened septa, somewhat longer and narrower toward lobe apices but not ultimately becoming capillary, the surface finely striolate to often distinctly papillose, the penultimate cell 10–12 µm wide × 41–60(72) µm long; terminal cell of uniseriate row ± straight, not curved to sinuous, slightly tapering to a ± rounded apex, 7–11 µm wide, but the length variable: 55–85(100) to 100–150 µm, usually thin-walled in the tip, the surface smooth to finely papillose; margins of lobes armed with pairs of opposing cilia, the cilia usually branched, often repeatedly, the armature all inserted on the abaxial surface of lobe and abaxially patent; marginal cilia of lobe uniformly uniseriate throughout, the cells similar to those of the uniseriate sector of leaf lobes; sinus bases plane and not reflexed. Disc weakly asymmetric, consisting of a low, wide strip 2–3 (very locally 4) cells high (from base to sinuses); margins of disc with branched cilia similar to those of lobes, the cilia sometimes abaxially displaced and lying at right angles to the disc plane. Cells of disc uniformly slightly to distinctly thickened, in somewhat regular tiers, in lamina middle 14–24 µm wide × (30)36–50(58) µm long; surface long-striolate, rarely with a few papillae. Underleaves somewhat smaller than leaves, free, subreniform, quadrifid, the armature similar to leaves; disc 2–3 cells high.
Androecia intercalary on primary branches and sometimes also the main shoot, the bracts divided to ca. 0.3–0.5, the lamina strongly ventricose, the abaxial face with ciliiform, unbranched processes (at times sparsely developed), the bract lobes similar to those of leaves; antheridia large for bract size, 1 per bract, the stalk biseriate. Coelocaule on main shoot or short to leading branches, but becoming axillary or pseudolateral (through development, respectively, of 2 or 1 subfloral branches), the coelocaule stoutly to longly and narrowly clavate, densely paraphyllose.
Capsule (only old valves with ± collapsed cells seen), the wall of (?)6 layers; epidermal layer of large, hyaline ephemeral cells lacking thickenings; innermost layer of cells with semiannular bands common, rather narrow, usually complete, rarely forked.
Spores 11.9–14.4 µm in diam., with low, rather well-defined, close papillae and short-vermiculate markings. Elaters bluntly pointed at the ends, 11–11.9 µm wide, somewhat contorted, bispiral, the spirals 1.9–2.4 µm wide.
Distribution and Ecology : New Zealand: Stewart Island, South Island (30–600 m), North Island (100–425 m), Chatham Islands (80–160 m); Australia: Queensland. In New Zealand known from Otago (Dunedin), Westland (near Westport, Mahinapua), Sounds–Nelson (Pelorus Sound), Southern North Island, Taranaki, Volcanic Plateau, Gisborne, Auckland and Northland EPs.
Occurring sporadically throughout its range, but most common in the eastern North Island. Found under a variety of lowland forest types that include Beilschmiedia tawa, Weinmannia racemosa, Melicytus ramiflorus, Nothofagus fusca, N. menziesii, Prumnopitys taxifolia and Dacrycarpus dacrydioides in sites ranging from very damp sites in stream courses to dry overhanging banks. Found on rotten logs, soil, tree roots, tree stumps, thin soil over rock, rarely epiphytic on Dicksonia squarrosa and (on Chatham Island) Dracophyllum arboreum. It may be corticolous, e.g., on trunk of Weinmannia at sea level to ca. 45 m in a narrow stream system with a canopy of Weinmannia racemosa at Port Pegasus, Stewart Island or, in the North Island, on the base of Rhopalostylis sapida (Kiwanis Reserve, N edge of Herekino Forest area, ca. 60–80 m) in a mixed broadleaf forest dominated by Beilschmiedia and Vitex lucens, with Rhopalostylis, Coprosma, Dacrycarpus and Hoheria. It occasionally occurs over shaded rock, e.g., on the summit of ridge at Bream Head (SE of Whangarei, 425 m) in a scrubby forest with a few large Dysoxylum and Beilschmiedia, but with much Coprosma, Rhopalostylis, Hoheria and climbing Metrosideros. The species ranges as far north as Radar Bush (WSW of Cape Reinga) at ca. 100 m in a forest of Beilschmiedia – Vitex – Hoheria and Cyathea dealbata. Species found with Trichocolea hatcheri are Bazzania adnexa, Camptochaete angustata, Categonium nitens, Chiloscyphus muricatus, Cyathophorum bulbosum, Distichophyllum pulchellum, Fissidens asplenioides, Heteroscyphus coalitus, Hymenophyllum flabellatum, Leiomitra lanata, Lopidium concinnum, Pyrrhobryum bifarium, Racopilum convolutaceum, Radula buccinifera, R. grandis, Schistochila appendiculata, Telaranea herzogii, Temnoma pulchellum, Thuidium laeviusculum and Trichomanes venosum.
Comments : Apart from its smaller size, appressed habit, and ± regularly bipinnate branching, there is little to distinguish Trichocolea hatcheri vegetatively from T. mollissima. However, many of these smaller, appressed, bipinnate plants bear abundant and well-developed coelocaules, a fact that argues for maintaining these plants as distinct. Several characters are commonly associated with this smaller habit. The cells of the uniseriate portion of the leaf lobes are less tapered, have thinner walls with only slightly thickened septa, and often have a distinctly papillose surface. The terminal and penultimate lobe cells are usually shorter and less finely tapered than those of T. mollissima, and the terminal cell is narrowly rounded and not thickened in the tip. When ♂ plants are present the two species may be readily separated, with T. hatcheri having less deeply lobed bracts that are armed on the abaxial surface of the lamina, and the presence of androecia only on primary branches.
More easily distinguished from Trichocolea mollissima in the field than from dried specimens by its vivid green color and velvety appearance due to the cilia being chlorophyllose (in contrast to the paler yellow color of T. mollissima), and by its invariably prostrate habit. The terminal branches lack the open cage of leaves seen in T. mollissima because the leaves tend to lie flatter to the stem. Trichocolea hatcheri is a smaller, more compact plant than T. mollissima, with a quite different distribution and ecology. It tends to grow on thin mineral soil over rocks (sometimes with Treubia lacunosa) and grows closely creeping over the substrate. Even vigorous plants rarely exceed 3–5 cm long and are, usually, rather closely 2(3)-pinnate, with tertiary branches usually sporadic or rare.
There has been a confusion in names applied to this species and Trichocolea mollissima. Hatcher (1958) used the name T. mollissima for this taxon (T. hatcheri), and used the later name T. australis Steph. for the true T. mollissima. Schuster (1963b) proposed T. novaezelandiae as a substitute for “ T. mollissima ” of Hatcher, but without the required Latin description. Hodgson (1965) subsequently described the species as T. hatcheri.
Trichocolea hatcheri belongs to a complex that includes T. pluma. The two species are similar, for example, in having 2(3)-pinnate branching and a leaf disc 2–3 cells high. Trichocolea pluma differs from T. hatcheri in having a terminal cell of the leaf lobes that is rather thin-walled, ± parallel-sided throughout with a surface distinctly striate-papillose. In these respects T. pluma is more like T. rigida, and, moreover, like that species the tip cell of the leaf lobes is rounded at the summit. Trichocolea pluma may be distinguished from T. rigida by the regularly 2(3)-pinnate branching, by the straight or dilated septa of the cells in the cilia and by the lower leaf disc.
