Marsupella sparsifolia (Lindb.) Dumort.
Marsupella sparsifolia subsp. childii R.M.Schust., J. Hattori Bot. Lab. 80: 61. f. 10. 1996.
Type: New Zealand, South Is., Fiordland Natl. Park, Mt. Burns track, 4500–5000 ft., Schuster 84-142.
Plants erect, fuscous or deep brown, 620–700 µm to 770–1160 µm wide in sterile sectors, 5–9(15) mm high. Branching common in basal sectors of plant, typically absent above, the branches lateral-intercalary, from ventral end of leaf axil; stoloniform axes infrequent or occasional. Stems brownish. Leaves remaining almost identical in size and form to near the gametangial region, almost immediately stiffly laterally spreading and remaining so ± throughout shoot, remote, the bases not at all sheathing, essentially transversely oriented and inserted, the leaves distinctly concave, mostly ± symmetrically ovate to ellipsoidal, rather sharply narrowing toward the base, 360–520 µm wide × 400–620 µm long, bilobed to ca. 0.15–0.2 to 0.3–0.35, sometimes a little asymmetrically so, with one lobe slightly larger than the other; lobes usually sharply acute or subacute, terminating in a single cell or a uniseriate row of 2 cells; sinus usually broadly V-shaped, blunt to subacute at base, sometimes narrowly rounded. Cells with trigones large and convex-sided to knot-like, the cells small, the median cells 12–18 µm wide × 14–22 µm long, the basal cells appreciably larger, 15–22 µm wide × 17–26 µm long; surface smooth or inconspicuously striate. Oil-bodies occupying a conspicuous portion of cell lumen, glistening, appearing whitish, (1)2(4) per median lamina cell, at base more commonly 3 or 4 per cell, granular-finely papillose, at times with a depression, the oil-bodies globose to broad-elliptic, 3.8–4.8 × 6.7–8.6 µm to 5.5–6 × 10–11 µm, spherical ones 4–5.8 µm in diam., if one per cell then often very large.
Paroecious, but fertilized gynoecia infrequent. Androecial bracts abruptly larger than leaves immediately below, in 2–3 pairs, more concave and much larger than leaves, bilobed to ca. 0.2; antheridia 2 per bract, the stalk 10–11 cells long, biseriate. Gynoecial bracts erect, mutually involute, sheathing the abbreviated perianth, the base ± clasping the stem. Perianth delicate, low, formed of delicate, narrowly rectangular cells, those near the mouth hyaline, colorless and notably leptodermous, the pigmented cells below with distinct trigones; mouth truncate, crenulate by cells that are finger-like and free only near the distal end. Calyptra with sterile archegonia near its base.
Seta with 20 rows of outer cells surrounding an inner core of 23 somewhat smaller cells, the exposed wall rather thick. Capsule spherical, the wall fragile, brittle, 2-stratose, 17–20 µm thick, the outer layer of cells somewhat thicker than inner layer, the outer layer of cells with sharply defined, strong, nodular thickenings that often appear clavate in surface view; inner layer of cells with similar nodular thickenings but moderately to much smaller, semiannular bands rare and isolated.
Spores pale brown, 9.1–10.6 µm in diam., the wall with low but sharply defined, short, often furcate, vermiform ridges; spore:elater diam. ratio 1–1.3:1. Elaters moderately tortuous, 8.2–9.6 µm wide, bispiral to tips, the spirals 2.9–3.8 µm wide.
Distribution and Ecology : New Zealand: Stewart Island (ca. 30 m), South Island (1220–1830 m); subspecies childii is endemic to New Zealand. Known from Fiordland (Mt. Burns), Southland (Eyre Mtns.), Otago (head of Wye Creek, Remarkables), Westland (ridge between Young and Blue rivers) and Canterbury (Harman Pass) EPs.
At the margins of rills in the alpine zone (e.g., on the plateau and slopes below Mt. Burns, Fiordland Natl. Park), in seepage areas and on alpine tarn margins, on soil or stones, sometimes in Oreobolus pectinatus and O. pusillus cushionfield. In these alpine sites it occurs characteristically with Diplophyllum verrucosum, but also with Andreaea acuminata, A. subulata, Blindia robusta, Cephalomitrion aterrimum, Cryptochila grandiflora, Drepanocladus revolvens, Hepatostolonophora rotata var. rotata and Hygrolembidium acrocladum. On Stewart Island the plant occurred over bedrock in a very humid niche that is often inundated or totally saturated (at top of Belltopper Falls, Port Pegasus, North Arm). Interestingly, the site is only 30 m elevation. In the upper Wye Creek (Remarkables, Otago, 1830 m) it forms cushions on soil on a tarn margin, which are at times at the water’s edge but at other times may be 50 m from the water’s edge. On Harman Pass (Main Divide 15 km SW of Arthur’s Pass, 1320 m) it occurs on soil at the margins of small tarns among cushionfields of Oreobolus and on bedrock kept wet by seepage. Schuster (1996d, p. 64) commented that the taxon “may form extensive mats . . . where subject to submersion, over stones and peaty soil on stones, at the edges of alpine tarns.”
Comments : The above description is based solely on New Zealand plants.
This is a larger plant than our other species, Marsupella sprucei, being 650–1100 µm wide, 8–15 mm tall vs. to 450 µm wide and typically 2–5 mm tall in M. sprucei. Also, the leafy shoots are subequally leafy throughout or only gradually smaller-leaved below in M. sparsifolia (Fig. 176: 1) vs. leafy shoots abruptly larger-leaved distally and almost always eventually fertile in M. sprucei.
This species may be confused with species of Allisoniella, particularly A. scottii. The form of the gynoecial apparatus will immediately distinguish Marsupella from Allisoniella, but problems may occur when only sterile plants are at hand. Two of the three species of Allisoniella that occur in New Zealand have sulcate leaf lobes, vs. plane leaf lobes in M. sparsifolia (Fig. 176: 1–3); the character may be observed in the field. Allisoniella scottii, however, has plane leaf lobes and in such cases one should search for branching modalities: A. scottii has ventral-intercalary branches vs. lateral-intercalary in M. sparsifolia (Fig. 176: 3). (For further comments see under Allisoniella scottii.)
