Cryptochila nigrescens (Steph.) Grolle
Jamesoniella nigrescens Steph., Hedwigia 34: 48. 1895.
Cryptochila nigrescens (Steph.) Grolle, Feddes Repert. 82: 15. 1971.
Type: New Zealand, Great Barrier Is., Kirk 87.
Plants erect-ascending from a prostrate leafless axis (or prostrate in thin mats on sandy soil), firmly anchored by stolons, reddish to reddish brown, to 1.5 mm wide. Stems rigid, becoming brownish, the cortical cells in 2–3 layers of thick-walled, colorless to moderately brownish cells; medullary cells thin-walled, colorless. Paraphyllia short-filamentous to scale-like, sparsely present on dorsal side of stem between the leaves (at least on robust shoots). Rhizoids sparse, frequently confined to stolons, at times also on ventral side of normal leafy shoots (on prostrate shoots). Branching exclusively ventral-intercalary, in sterile sectors nearly exclusively basal; microphyllous stolons sporadically present. Leaves imbricate, vertically oriented, shell-like, concave, when dry loosely appressed to the stem, when moist obliquely spreading from a short-sheathing base, the insertion transverse to weakly succubous, distinctly crossing the midline dorsally; leaves broadly elliptic to orbicular (at times ovate with a subcordate base), 1000–2250 µm wide × 1100–1750 µm long, entire, contracted to the base, the apex broadly rounded to (rarely) retuse; dorsal margin usually distinctly inflexed, moderately arched, not or slightly decurrent; ventral margin plane, moderately to distinctly arched, often contracted to base, short-decurrent. Cells in indistinct concentrically aligned rows, quadrate to short-rectangular, thin-walled, with distinct, medium and straight-sided to bulging to knot-like trigones; cells of median portion of leaf 20–24(27) µm wide × 27–35 µm long; median-basal cells somewhat elongate, but not forming a sharply demarcated field; surface smooth or finely and delicately but somewhat remotely papillose lending a “speckled” appearance, the basal cells faintly longitudinally striate-papillose. Underleaves absent or uniseriate, filamentous and caducous; ventral merophyte row very narrow.
Androecia on leading shoots, of similar width to vegetative sectors, with up to 8 pairs of bracts; bracts saccate in basal portion; lobule weakly developed, inflexed, semicircular, the free margin entire; antheridia solitary, the stalk biseriate, the stalk cells very thick-walled. Gynoecia usually not innovating, the bracts not much larger than vegetative leaves, those of innermost series of similar size to those below, free from one another, on one side irregularly shallowly lobate-laciniate, on the other undivided and broadly rounded; bracteole narrowly to broadly united with one of the bracts, lanceolate to linear, at times as long as the bracts. Perianth elongate-ovate, the upper 0.5 or more of the perianth deeply plicate and twisted, the perianth contracted to the somewhat truncate mouth; mouth shallowly and bluntly lobulate, entire to weakly crenulate, the marginal cells short-rectangular to moderately long-rectangular, with evenly thickened walls without trigones; perianth 2–3-stratose in basal portion.
Capsule ellipsoidal, the wall about 55–65 µm thick, 5–6-stratose; outer layer of cells with radial longitudinal walls thin-walled, with nodular to short spur-like thickenings primarily on alternating radial walls; innermost layer of cells irregular in shape, the radial longitudinal walls with discontinuous sheets of wall material, mostly with nodular to spine-like thickenings, only sporadically with complete semiannular bands.
Spores 15.4–17.3 µm in diam., finely and closely papillose. Elaters bispiral to tips, 7.2–8.6 µm wide.
Distribution and Ecology : Endemic to New Zealand: South Island (ca. 150–1010 m), North Island (30–540 m), Chatham Islands (80–240 m). Known from Western Nelson (Stockton Plateau, Punakaiki), Southern North Island (Eastbourne), Volcanic Plateau (Rotorua), Gisborne (Mahia Peninsula), Auckland and Northland EPs. Most common in the northern half of the North Island, but the highest recorded elevation is from the summit of Mt. Augustus (Stockton Plateau, 1010 m).
The species has a sporadic distribution and typically occurs over clayey soil of banks. For example, it occurs over a wet, silty roadside bank draining a pakihi (1 km N of White Horse Creek, near Punakaiki, ca. 150 m) or on a roadside bank with Blechnum beneath Agathis forest (N of bridge on State Highway 12 over Waipoua River, Northland, 110 m). At Takapuna (Auckland) it has been collected on coastal cliffs. Also on granitic roadside banks covered mostly by hepatics, mosses, Blechnum and Stereocaulon (N side of Tiropahi River, 145 m). Also found on a vertical, moist, shaded bank in a scrub forest of Leptospermum scoparium, Weinmannia silvicola and Dacrydium cupressinum (ridge between Webb Creek Track and Billy Goat Track, Coromandel Forest Park, 510–540 m). In the Rotorua area it has been found on thermal ground with Campylopus clavatus. Other associated species are Cladia aggregata, Fissidens tenellus var. tenellus, Herzogianthus vaginatus (on Rainbow Mtn., Rotorua) and Jamesoniella colorata.
Comments : This species is clearly distinct from related New Zealand species by the broadly overlapping dorsal leaf bases, with leaf insertions extending across and well beyond the dorsal stem midline (Fig. 161: 1). This condition lends a zigzag appearance to the leaf bases in dorsal aspect (Fig. 161: 1). However, ♂ bracts of Cryptochila grandiflora also have this zigzag appearance and the presence of trigones should be used to confirm the species. The species otherwise bears a superficial resemblance to Jamesoniella colorata, but lacks the coarse, guttulate papillae of that species. In addition, the dorsal margin of the leaves is not decurrent (Fig. 161: 1) as in other New Zealand species of Jamesoniella and Cryptochila.
