Heteroscyphus knightii (Steph.) Grolle

Engel, John J., He, Xiaolan & Glenny, David, 2010, Studies on Lophocoleaceae XXII. The systematic position of Amphilophocolea R. M. Schust. together with comments on the status of Tetracymbaliella Grolle and Lamellocolea R. M. Schust., Phytotaxa 9, pp. 41-52 : 47-51

Heteroscyphus knightii (Steph.) Grolle

Chiloscyphus knightii Steph., Sp. Hepat. 3: 245. 31 Jan. 1908. Heteroscyphus knightii (Steph.) Grolle, J. Hattori Bot. Lab. 61: 251. 1986. Type: New Zealand, Knight .

Chiloscyphus tridentatus Mitt. in Hooker f., Bot. Antarc. Voy. 3: 228. pl. 179, f. 1. 1859, syn. fide Hodgson (1943). Heteroscyphus tridentatus (Mitt.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 401. 14 Jan. 1985 (1984), non H. tridentatus (Sande Lac.) Grolle in Grolle & Piippo, Acta Bot. Fennica 125: 68. 3 April 1984 Ξ Lophocolea tridentata Sande Lac., Ann. Mus. Bot. Ludg. Batav. 1: 296. 1864 (Java, New Guinea). Type: Tasmania, Dumont d'Urville, Archer; Grass-tree Hill, Oldfield; St. Patrick's River, Gunn.

Saccogyna trilobata Steph., Sp. Hepat. 3: 270. 29 Feb. 1908, syn. fide Hodgson (1958). Type: New Zealand, Colenso .

Chiloscyphus conistipulus Steph., Sp. Hepat. 6: 304. 1922, syn. cf. Grolle (1961a). Type: New Zealand, Mickeljohn .

Amphilophocolea sciaphila R.M.Schust. , Nova Hedwigia 72: 98. f. 1. 2001, syn. nov. Holotype: “ New Zealand: North Island, E. border of Tongariro Natl. Park: Tree Trunk Gorge; on peaty soil under Blechnum , deeply shaded rocks ( RMS 95-770 ).” (herb. R. M.Schuster).

Plants firm, resembling Bazzania tayloriana in aspect, loosely creeping to slightly ascending, often forming thin, pure, felt-like, loosely attached, sheet-like mats, occasionally occurring as scattered shoots among other bryophytes, dull and opaque, distinctly glaucous and water repellent, the shoots small to medium, to 2 mm wide, with a distinctive appearance when dry: the dorsal and ventral margins sharply deflexed. Branching infrequent, the branches mostly ventral-intercalary, often in lateral half of underleaf axil; Frullania - type branches occasional; stolons lacking. Stems narrow for plant size, the cortex weakly differentiated, in 1(locally 2) rows of feebly smaller cells, with both cortical and medullary cell walls pale yellow brown and similarly thickened. Rhizoids sparingly developed, hyaline, in tight fascicles from stem at immediate base of underleaves. Leaves subopposite (alternate in suboptimal plants), ± horizontal to sometimes dorsally assurgent, widely spreading, often at 90° to stem, approximate to weakly imbricate, free dorsally, orientation and insertion strongly succubous, the insertion almost longitudinal, forming a ± straight line for its entire length, the lines of insertion rather distant from stem midline dorsally and delimiting a leaf-free strip of 4–6 cells wide; leaves slightly convex, subsymmetrically to at most moderately asymmetrically ovate-subquadrate to oblong ovate; apex subtruncate, variable: (2–)3(–5)-dentate (weaker shoots with bidentate apices moderately common), typically with tooth in ventral half or middle of leaf apex larger, broad-based, and often ± apiculate or at times narrowly rounded at the summit, the apex often with the ventralmost and dorsalmost teeth displaced toward leaf base, the displaced teeth usually broad based, the largest tooth at the leaf apex entire margined, terminating in a single cell (or a pair of laterally juxtaposed cells) or a uniseriate row of 2–3 thick-walled, isodiametric to slightly elongated cells, the terminal cell moderately tapering to a narrowly to broadly rounded summit; apex of suboptimal plants variable: truncate to retuse to 2–3-lobed, with the lobe summit often rounded; dorsal margin broadly arched, typically entire, exceptionally with a small tooth in median portion, short to moderately decurrent; ventral margin ± straight to slightly arched, entire. Cells of median portion of leaf evenly thick walled, the middle lamella distinct, the cells rounded at the angles, trigones absent, median leaf cells 18–25 µm wide, 20–28 µm long; basal cells a little larger but not elongated; surface distinctly glaucous, the surface with a scurfy appearance. Oil-bodies found throughout leaf, large for cell size, hyaline and somewhat glistening or very pale dull gray, 2-4 per median leaf cell, coarsely botryoidal, the spherules clearly defined and rather uniform in size, the oil-bodies elliptic to (often) irregularly fusiform to subcrescentic, sporadically subtriangular in profile, 6.5–11.1 µm × 3.3–4.6 µm, the globose ones 4.6–5.2 µm in diam. Underleaves 1.4–1.7X the stem width, united to the leaves on both sides, the connate portion 2–5(6) cells wide, the body of the underleaf positioned above the attached pair of leaves, the insertion inverted "U"- shaped, the apex of insertion reaching to about the midpoint of the leaf pair next above; underleaves weakly spreading, distant, with much of the stem exposed below the "U"-shaped insertion at each underleaf base, the underleaves plane to concave (ventral view), oblong-ovate, the lamina ± subquadrate to transversely rectangular (e.g., wider than long); apex bifid to 0.5–0.7, the lobes ± parallel, narrowly acuminate to subcaudate, entire, ending in a uniseriate row of up to 6 at most moderately elongated, thick-walled cells, the tip cell often capped by a slime papilla; lamina margins on each side with a dentiform to laciniiform process at or a little below the level of the main sinus, the margins otherwise entire or with a small tooth near the base, in suboptimal plants the margins with smaller teeth or completely entire, the sinus at the leaf to underleaf connation broadly angular, at times at 90°, reflexed or not. Asexual reproduction absent.

Plants dioecious. Androecia minute for plant size, short to somewhat long spicate, on reduced, abbreviated, determinate ventral-intercalary branches hidden by lateral leaves above or slightly extending beyond them, the branch origin somewhat variable: often displaced slightly apical of underleaf axil or to ventral-lateral side of stem; bracts cucullate, so much so that a dorsal pocket is not defined, the bracts dorsally assurgent, tightly appressed, decidely leptodermous, the margins with 2–3 small teeth and copious slime papillae, the bracts monandrous; antheridial stalk biseriate; bracteoles much smaller than underleaves, connate on both sides, without antheridia. Gynoecia on highly abbreviated ventral-intercalary branches; bracts small, the innermost bracts bifid to ca. 0.4, the lobe margins with a few teeth, the lamina margins irregularly denticulate-dentate, the teeth often terminating in a slime papilla. Perianth inflated, somewhat dorsiventrally compressed, the mouth laciniate-lobulate, each narrow lanceolate, tapering to a uniseriate row of 3–6 at most slightly elongated cells, the tip cell tapering to a narrowly rounded summit, the lobes comprised of evenly thick-walled cells.

Sporophyte unknown.

Distribution: — New Zealand: South Island (220–1500 m), North Island (ca. 700 m [type of A. sciaphila ]– 1240 m); Australia: Tasmania (sea level– 1000 m).

Comments: — Suboptimal plants are smaller, alternate-leaved, and have leaf apices that are variable and range from 3-lobed and with lobes that are often rounded at the summit to retuse to bilobed by two rounded lobes (the ventral lobe usually a little larger) to undivided and truncate. Occasional leaves in such populations have sharp lobes, with the middle of the 3 lobes larger as in well-developed phases. Such suboptimal populations have underleaf lamina margins with a small tooth or are altogether entire. The suboptimal phase of the species matches the description and figures of Amphilophocolea sciaphila in Schuster (2001, fig. 1). Also, Schuster (2001, p. 98) stated that the underleaves of A. sciaphila are conspicuously connate on one side but rarely and feebly so on the other side. The senior author has observed that in species of Chiloscyphus and Heteroscyphus with leaves connate on both sides, suboptimal plants are typically distinctly connate on the side nearest the adjacent leaf, but on the opposing side are more narrowly and obscurely connate or altogether free. Also, the alternate leaf arrangement and presence of blunt teeth at the leaf apex of A. sciaphila coincides with less well-developed plants. The suboptimal phase of the species typically occurs deep in cave-like recesses and plants are notably strongly glaucous. The stronger glaucous condition, along with the morphological features noted for suboptimal plants such as reduced teeth of the leaf apices and underleaf margins, are likely correlated with particularly sheltered, dimly lit niches.

The species may be recognized in the field by the glaucous condition, the small plant stature and the distinctive toothing at the leaf apex. Leaf apices are (2–)3(–5)-dentate with the tooth in the ventral half or the middle of leaf apex typically larger ( Fig. 3 : 1, 4–6). In three-lobed leaves the teeth on either side of the large, median tooth are each displaced toward the leaf base, but all teeth are typically in the distal 0.2 of the leaf. The degree of development of the glaucous surface seems to be correlated with degrees of exposure to light; particularly strongly glaucous plants typically grow in low-lit niches.

Branches in H. knightii are mostly ventral intercalary. Branches are variable in position within the underleaf axil and occur in the middle of the underleaf axil but often are present in various loci in the lateral half of the underleaf axil as well. Terminal, Frullania - type branches are occasionally present. Schuster (2001) recorded only ventral-intercalary branches for Amphilophocolea sciaphila .

Figures

FIGURE 3. Heteroscyphus knightii (Steph.) Grolle. 1. Sector of leading shoot, dorsal view. 2. Sector of leading shoot, ventral view. 3. Cladograph (U-shaped symbols = gynoecia). 4. Leaf pair and attached underleaf. 5-7. Leaves (all at same scale). 8. Leaf apices. 9. Portion of median lobe of 3-lobed leaf. 10. Median leaf cells. 11. Underleaf. (All from Engel 13121, Tasmania, Tasman Peninsula, near Taranna, near junction of Camp Road and Balt Spur Road.)