Flora of New Zealand Series

Jungermannia undulata L., Spec. P1., p. 1132. 1753.

Martinellius undulatus (L.) Gray, Nat. Arr. Brit. Pl. 1: 691. 1821.

Radula undulata (L.) Dumort., Syll. Jungerm. Europ. 40. 1831.

Scapania undulata (L.) Dumort., Recueil Observ. Jungerm. 14. 1835.

Plagiochila undulata (L.) Mont. & Nees in Nees, Naturgesch. Eur. Leberm. 3: 520. 1838. 

Type: Northern Europe.

For a complete synonymy see Schuster (1974a).

[Plate 15B; Fig. 169: 2, oil-bodies, p. 766; Fig. 170]

Plants pale to dark reddish brown, rather transparent, 2–4 mm wide, the shoots strongly dorsiventrally flattened. Branching not seen. Stem deep reddish brown (markedly more pigmented than leaves), the cortex well developed, clearly differentiated, 2–3-stratose, of very prominently thick-walled cells; medullary cells larger, thin-walled. Rhizoids not seen. Leaves loosely imbricate, the keel 0.25–0.6 the ventral lobe in length, typically distinctly winged, the wing at times only a narrow strip of tissue, entire, the keel exceptionally with paired wings, the keel slightly, broadly arched inward, the degree of curvature somewhat variable, the keel-stem angle 80–90°. Ventral lobe flat to at most moderately and gently decurved, broadly obovate, 930–2000 µm wide × 1300–2000 µm long, the width (0.70)0.9–1× the length, arching ca. 0.75 across stem to somewhat beyond the stem, the lobe-stem angle 75–85°; apex usually broadly rounded and with teeth ± similar in size and form, the apex with only a suggestion of more prominent tooth and then subapiculate (the more prominent tooth broad-based and with a uniseriate row of 2 cells), the apex sporadically obtusely pointed; margins of lobe entire or subentire in the basal half (of both ventral and dorsal margin), the distal half sparingly denticulate, the teeth at times consisting of 1 tapering or non-tapered cell at most only slightly longer than wide, or the teeth 2 cells long and 1–2 cells wide at base, the terminal cell rounded or angled; ventral margin at base narrowed into a gradually attenuated, long-decurrent strip. Dorsal lobe with insertion transverse, the lobe ± plane to slightly convex for most of its length but the distal sector sharply decurved, 0.55–0.65 the ventral in size, orbicular-ovate to oblate-rectangulate, the width 1.1–1.3 the length, arching across and well beyond stem, the apex mostly subtruncate, occasionally obtuse-rounded, the apex and distal sector of free margin sparingly crenulate by 1–2-celled teeth or by an angular projection of the exposed wall; free margin not decurrent at base. Cells of median sector of ventral lobe with bulging trigones and thin intervening walls, 16–22 µm wide × 19–31 µm long; marginal cells (median sector of lobe) slightly firm-walled and with bulging trigones, often with bulging septa, a border not differentiated, the cells subisodiametric, 14–18 µm wide and long; surface striate-papillose. Oil-bodies occupying moderate portion of lumen, hyaline and somewhat glistening, 3–6(7) per median cell of ventral lobe, coarsely granular, globose to ovoid to broadly elliptic, a few subdeltoid in profile, often irregular in shape, often with a depression or irregular fold or crease, 3.8–5.8 × 7.7–10.1 µm, a few 6.7 × 10.6–11.5 µm or 3.8–4.8 × 10.6–12.5 µm, subglobose ones 4.8–5.8 µm in diam. Chloroplasts rather large. Gemmae, when present, produced in short chains from immature leaf lobes, 1-celled, broadly ovoid to ellipsoidal.

Androecia and gynoecia not seen.

Distribution and Ecology : Bipolar, in the Holarctic occurring throughout the subarctic well into the Arctic; apparently incompletely circumboreal-circumpolar, since it appears absent from Siberia (cf. Schuster, 1974a for comments on distribution). In the Southern Hemisphere known from two South Island collections, both from Otago EP: Old Man Ra., 1340 m, in alpine flush in a sedge–moss bog (5/10/66, T. Daly 14609, dupl. ex herb. G. A. M. Scott [JE!]), and Remarkables, Rastus Burn Skifield, 1630 m, found in a flush through Chionochloa pallens tussockland, in an Oreobolus pectinatus cushionfield, with Psychrophila obtusa, Celmisia discolor, Marchantia foliacea, Bartramia papillata and Euchiton mackayi (WELT H10109!).

Comments : We refer the New Zealand population to Scapania undulata with some hesitation. On the one hand plants from New Zealand have several characters that define S. undulata, such as the ventral lobe narrowed at the base into a gradually attenuated, long-decurrent strip (Fig. 170: 3), and the dorsal lobe insertion transverse with the free margin not decurrent (Fig. 170: 1, 2). On the other hand, the New Zealand and Northern Hemisphere populations differ in a number of respects, as follows.

The description of the species is based on a small specimen from New Zealand very kindly sent to the senior author by the late Riclef Grolle, and two collections at WELT and CHR.