
Genus Acromastigum Evans
Mastigobryum B (in great part), G. L. et N., Syn. Hep., 218, 1845.
Mastigobryum (Section) 111 Inaequilatera Steph., Hedwigia, 25, 245, 1886.
Bazzania Section 111 Inaequilaterae Schiff.
Acromastigum Evans, Bull., Tori. Club, 27, 103, 1900.
Mastigobryum (Subgenus) Inaequilatera Steph., Bull., Herb., Boissier 11, 8, 408, 1908.
Plants small to medium, light green or strongly pigmented with brown, loosely matted, or in denser cushions, or creeping amongst other hepatics on earth. Stems prostrate, branched as in Bazzania, but ventral flagellae not axillary. Leaves bidentate with 2 exceptions, which are entire and squarrose, otherwise incubous, tending to be unequally bilobed, insertion oblique. Stipules small, often with bulging sides, entire or 3-lobed. Cells larger in the ventral part, arranged in rows, sometimes forming a vitta, cell walls thickened, usually with trigones.
♀ branches short, ventral, axillary, not well known. Perianth as in Bazzania.
♂ bracts delicate, in the form of hollow sacs, monandrous.
| 1. | Plants small (in New Zealand), stems not more than 1 cm. long, leaves entire or subentire, squarrose with transverse insertion | Squarrosa | 2 |
| Plants larger, stems longer than 1 cm., leaves unequally bilobed obliquely inserted | Inaequilatera | 3 | |
| 2. | Leaves ovate, apices regular | A. integrifolium | |
| Leaves triangular-ovate, with the apical portion sometimes curved upwards, apices curiously variable | A. verticale | ||
| 3. | Leaves pigmented, stems blackish, rigid, ventral leaf-lobe always larger or longer than the dorsal | 4 |

| Leaves light green, paling when dry, but never pigmented with brown | 6 | ||
| 4 | Leaves very small, 0·35–0.45 mm. long, lobes much reduced, cells bistratose in patches, vitta indistinct, rare | A. brachyphyllum | |
| Leaves larger, with, lobes generally not reduced, ventral vitta of large cells very distinct | 5 | ||
| 5. | Plants robust, ventral lobe of leaf linear-ligulate, of 2 cells in width, those of opposite leaves overlapping on ventral side of stem | A. Mooreanum | |
| Plants a little less robust, ventral lobe of leaf not produced, but more triangular from a broader base | A. anisostomum | ||
| 6. | Leaves 0.7–0.8 mm. long, not or scarcely imbricate, lobes subparallel, dorsal lobe mainly larger than the ventral, stipules quadrate, cells 20–30μ | A. Colensoanum | |
| Leaves 0.3–0.5 mm. long, imbricate, narrowly margined, dorsal lobe mostly reduced to a tooth on a crenation, stipules subcircular, cells 10–12μ | A. marginatum |
Acromastigum integrifolium (Aust.) Evans. Text-fig. 2, fig. 9.
Mastigobryum integrifolium Aust., Bot. Gaz. 1, 32, 1875.
Bazzania integrifolia Evans, Trans. Conn. Ac. 8, 225, 1892.
Acromastigum integrifolium Evans, Bull. Torrey Club, 27, 103, 1900; Ann. Bry., iii, 16, 1934.
Plants distributed through a small dry mixture of filmy fern roots, Lepidozia, A. anisostomum, etc., pale. Stems barely 1 cm. long, a little branched, with few flagellae. Leaves squarrose, with transverse insertion, ovate, 0·4 mm. long, 0·3 mm. vide, margins quite entire, apices obtuse. Stipules squarrose, somewhat smaller than the leaves, 0·3 mm., occasionally with a small sinus at the apex, otherwise broadly obtuse. Cell cavities very clear, fairly uniform in size throughout, ca. 0.25μ, many stellate in shape, caused by the large trigones with convex sides. Perianth basal on a very short branch, 3·5 mm., hyaline, linear-fusiform, cells rectangular, mouth scarcely ciliate. Invol. leaves similar to the cauline but appressed to the axis. ♂ inflorescence not seen.
The specimen differs from the Hawaiian plant, only in its small size, the measurements for that being given as, stems 3–8 cm. long, and the leaves 0·7 × 0·4 mm. That it should turn up in New Zealand is of great interest.
From Summit, Te Moehau Mt., Coromandel Pen. North Island, 960, L. B. M., 2/8/30.
The type specimen in Herb. W. H. Pearson. West Maui (Baldwin, 1875); Konahuanui, Ohau (Cooke, 1899).
Acromastigum verticale (Steph.) comb. nov. Text-fig. 2, fig. 13.
Mastigobryum verticale Steph., Spec. Hep., iii, 419. 1909.
Acromastigum Martinii Hodg. in lit. Bryophytes Stewart Island, ii, W. Martin, Trans. Roy. Soc. N. Z., 78, 496, 1950.
Plants consisting of isolated stems in a compact mat of minute Lepidozias with Radula dentata. Stems mostly unbranched, to 0·7 cm. long, 0·2 mm. thick, flagella mostly one on each stem, usually short, with minute, distant, retuse or entire leaves, becoming smaller and more distant towards the apex. Leaves ovate-triangular, squarrose or with the upwards part of the leaf curved upwards, or even hamate, transverse attachment, 0·6 mm. long. 0·4 mm. wide at the widest part, concave, apices variable. obtuse or bluntly acute, shortly bifid with divergent lobes or curiously curved backwards towards the ventral margin. Cells 30–40μ, still larger in the basal part, walls sinuous to stellate, caused by the very large

trigones with bulging sides. Stipules, the width of the stem or a little more, 0·3 mm. tall, ovate-rotund, mostly entire, rarely very shortly bifid, more regular in shape than the leaves. Perianth 3·5 mm. long, 0·5 mm. broad at the base, narrowed to the apex, month piliferous, hair-points to 0·3 mm. long, crooked and entangled, a little toothed and in one instance branched. Seta as long as the perianth. Innermost pair of invol. leaves reaching almost ⅓ up the perianth, with narrow apices, shortly bifid reflexed. Second pair reaching half-way tip the innermost, with similar apices.
The perianth is here described for the first time.
This species resembles A. integrifolium in its small size, transversely attached leaves and similar cells, but that species has purely ovate leaves with regular apices.
Stephani specially comments on the vertical (transverse) attachment of the leaves.
From a moist sandy soil, at head of Crooked Reach, Port Pegasus. Stewart.
That this species should be found with Radula dentata Mitt. on Stewart Island is a remarkable instance of discontinuous distribution, as both of these are Great Barrier Island plants. A. marginatum is also a northern plant.
The type was from Great Barrier Island, leg. Kirk.
Acromastigum brachyphyllum Evans. Text-fig. 2, fig. 12.
Acromastigum brachyphyllum Evans, Annales Bryologici Supp. Vol., iii, 1934.
Plants consisting of loose stems, coloured as in A anisostomum. Stems 6 cm., blackish, dichotomously branched from acute angles. Leaves scarcely contiguous to a little imbricate, obliquely spreading, small, 0·35–0·45 mm. long, 0·25–0·3 mm. broad at the base, bilobed, lobes triangular sometimes much reduced, apex usually decurved; ventral lobe the larger, scarcely 0.1 mm. long, sinus small acute; ventral margin straight or a little concave, mostly at an angle of 45 degrees from the axis, a little incurved. Dorsal margin strongly rounded at the base. Vitta of cells not clearly defined, and trigones indistinct, but the cells in the ventral area are larger than those in dorsal, ca. 25μ, decreasing to 10μ, at the dorsal margin and the upper portion of the leaf. Stipules as in A. anisostomum broader at the base and very obtusely trilobed. According to the author, there are patches of bistratose arrangements in the leaf, these regions involving 2–5 cells. Inflorescences unknown.
This species differs from A. anisostomum and A. Mooreanum in the small leaves with very short lobes, in the vitta being indistinct, and in the small areas of bistratose cells.
Type from Paparoa Range, Westland, 3,000ft., coll. by R. Helms, no. 4948 Bot. Div. Herb., in Kirk's collection.
Acromastigum Mooreanum (Steph.) comb. nov. Text-fig. 2, fig. 15.
Bazzania Mooreana Steph. Hedwigia, 33, 1, 1894.
Mastigobryum Mooreanum Steph., Spec. Hep., iii, 539, 1909.
Acromastigum anisostomum Evans, Ann. Bry Supp. Vol. iii, 48, 1934.
Plants in tufted cushions on the ground and trunks of trees, similar in appearance to A. anisostomum and like the latter, xerophytic. Stems to 6 cm., blackish in the lower part, usually twice dichotomous, apices inclined or subcircinate.

flagelliferous, flagellae fairly numerous, decurved. Leaves imbricate, narrowly triangular-ovate, decurved, glossy, from pale to orange or brown, near the bases of the stems, bilobed, the dorsal lobe triangular ca. 0·1 mm. long, ventral lobe 0·4 mm., long and narrow, often overlapping on the under surface of the stem, of 2 cells except in the vicinity of the base which may be broader or narrower than the base of the dorsal lobe; ventral margin reflexed, dorsal arched at the base. Cells in the dorsal area and the dorsal lobe small, ca. 10 or 12μ, in the ventral lobe ca. 30μ, diminishing in size towards the tip. The vitta of large pigmented cells, to 50μ × 30μ is adjacent to the ventral margin with one row of slightly smaller cells between; cell walls everywhere thick, with large trigones, cuticle faintly papillose along the margin. Stipules narrowed from a broad base, 0·2–0·25 mm., short, 0·1–0·15 mm.; lobes in most cases appear to be reduced to crenations. Inflorescences not seen.
This species is distinguished from A. anisostomum, by the very long and narrow ventral lobe, a noticeable distinction, and more important, a constant one; also by the vitta reaching practically to the ventral margin, and perhaps by the longer stems and crenate stipules. The “bridging over” between this and A. anisostomum seen by Evans in Cockayne's Stewart Island speciman of Mastigobryum Mooreanum det. Stephani from the Auckland Museum, really seems unimportant alongside the good and ample specimens of each collected by Mr. Martin. When the 2 kinds grow together in the same clump, the stems of each are always distinct. Rodway considered this species as a robust form of A. anisostomum and was hesitantly followed by Evans.
Not known as yet from the North Island.
South Island: Facile Harbour, Dusky Sound, Fiordland Excursion, H. H. A., 1946.
Stewart Island: On trees in subalpine forest, Table Hill, 481, 499, 501; Epiphytic on forest trees, Track, Pegasus to Tin Range, 524. On ground in dense forest, P. Pegasus, 539, on trees, head of Crooked Reach, P. Pegasus, 538, Islet in Sawmiller's Arm, P. Pegasus, 3928, W. M.; Port Pegasus, L. Cockayne.
The type was from Tasmania from specimens collected by Oldfield and Moore.
Acromastigum anisostomum (Lehm. & Lindenb.) Evans. Text-fig. 2, fig. 16.
Jungermannia anisostoma Lehm. & Lindenb., Pug. Plant., 6, 57, 1834.
Jungermannia atrovirens Tayl., Lond. Journ. of Bot., 388, 1844; Fl. Antarct., 1847.
Mastigobryum atrovirens G. L. et N., Syn. Hep., 219, 1845.
Mastigobryum anisostomum G. L. et N., Syn. Hep., 219, 1845; Lindenb., Spec. Hep.,
Fasc. 8–11, 17, 1851; Mitt., Fl. Nov. Zel., ii, 146, 1855; Hook. Handb. N.Z. Fl., ii, 524, 1867; Steph., Spec. Hep., iii, 539, 1909.
Bazzania anisostoma Trevis., Mem. 1st. Lomb., 13, 414, 1877; Rod., Pro. Roy. Soc. Tas. 75, 1916.
Mastigobryum chiloense Steph., Kungl. Svenska Vetensk.-Akad. Handl. 46, 59, 1911.
Acrormastigum anisostomum Evans, Ann. Bry., Supp. Vol. iii, 1934.
Plants in cushions on ground and trunks of trees, shiny, golden to olive brown. Stems rarely more than 2 cm., dark brown or blackish, rigid, brittle, sparsely dichotomously branched, flagelliferous, flagellae fairly numerous, decurved, ca. 1 cm. long with minute, distant, appressed subentire leaves. Leaves usually closely imbricate, golden, shading to brown, the lower ventral portion being more strongly pigmented, glossy, triangular-ovate, 0·4–0·6 mm. long to the tip of the ventral lobe, convex, strongly decurved, bilobed, sinus acute or obtuse, lobes variable in

size, the ventral larger, 1 ½ to twice the length of the dorsal, and usually wider, but sometimes narrower from a narrower base, dorsal lobe triangular. In some cases both lobes may be small, and leaves quite entire have been observed; dorsal margin arched at the base, ventral a little incurved or flat, sometimes minutely asperate along the margin. A vitta of very large cells to 50μ × 20–30μ, and 2–3 cells distant from the ventral margin extends along most of the leaf; cell walls thick, and in the area of the vitta, the trigones very large, often bulging into the sides of the cells. Cells in the dorsal area of the leaf 10μ at the margin, increasing to 30μ at the edge of the vitta. Stipules 0·2 mm. wide at the base, slightly auricled and mostly extending across the width of the stem, narrower at the apex, and only 0·1 mm. tall on stems examined, trifid to the middle, segments broadly obtuse. Invol. leaves in 3 rows, increasing in size upwards, perianth 3 mm. fusiform, 3-grooved in the upper half, mouth ciliate.
Mastigobryum atrovirens was reduced to synonomy on p. 717, Synopsis Hepaticarum. M. chiloense by Evans, p. 49, 1934.
This plant can be known by its coloration, its rigid-looking stems, with imbricate decurved, bilobed leaves. From Acromastigum Mooreanum it is distinguished by the ventral lobe not more than twice the length of the dorsal, and more than 2 cells wide, and as far as is known, by the shorter stems.
North Island: Summit Little Barrier, H159, W. M. Hamilton; Mt. Archeria, Little Barrier Is., R. E. N.; mossy forest, quite abundant, growing low and close on trees, Te Moehau ca. 2,400ft., H349, H64, L. B. M.
South Island: Lead Hills, Rainham, Nelson, 3,500–4,000ft., G. S. and S. T.; Westland, R. Hamilton, 4935 Herb. Bot. Div.
Stewart Island: On bank of stream in forest, Pegasus, 511, logs in forest, Pegasus Creek, 5341, Wet Banks, Tin Range, 540, common as cushion former, Pryse's Peak, 469, log in forest, Mt. Anglem, 345, W. M.
Auckland Is., on rock in upper border of the hygrohalophyte belt, 2303, G. Einar Du Rietz.
The type of J. atrovirens was from Auckland Is., in Hooker's collection. The earlier type was collected at Dusky Sound by Menzies, 1769.
Also from Tasmania, Australia, Chile, Patagonia and Straits of Magellan.
Acromastigum Colensoanum (Mitt.) Evans. Text-fig. 2, fig. 14.
Mastigobryum Colensoanum Mitt., Fl. Nov. Zel., ii, 147, 1855; Hook. Handb. N.Z. Fl., ii, 524, 1867.
Mastigobryum amoenum Col., Trans. N.Z. Inst., 19, 288, 1886.
M. minutulum Col, ibid.
Bazzania Colensoi Rod., Papers & Proc. Roy. Soc. Tas, 75, 1916.
Aoromastigum Colensoanum Evans in Reimers, Hedw., 73, 142, 1933; Ann. Bry., Supp. Vol. iii, 79, 1934.
Plants green, on earth, or rotting wood, mostly with other bryophytes. Stems procumbent, flexuose, loosely intricated, to 2 cm., branches few, to 0.5 cm., mostly dichotomous, both stems and branches with fairly frequent flagella Flagella 2–7 mm. long, with minute bifid leaves. Leaves contiguous to a little imbricate, insertion nearly straight, sometimes a little decurrent, oblong or ovate-oblong, 0·7–0·8 mm. long, cleft to ¼ to the length of the leaf, lobes subparallel, longly triangular-acute, sinus acute or rounded, the dorsal one 1 ½ times as big as the ventral, dorsal margin straight or convex near the base, ventral or a little concave;

leaf at the dichotomy, rounded-ovate, shortly bidentate. Trigones small or absent, cells ± quadrifid and uniform, 20–30μ. Stipules quadrate, mostly as wide as the stem, 0·2 mm. long × 0·2 mm. wide, 3-fid to the middle or just below, segments 2 cells broad, obtuse. Invol. leaves ovate, acuminate, deeply cleft with lobes converging, cells hyaline, oblong-quadrate to 40μ, or rhomboidal cells projecting little along the margin. Perianth fusiform, 3 mm. long pluriplicate from about ½ way up, lobes bifid, apices ciliate-toothed.
The medium size, green, bilobed, non-imbricate leaves enable this species to be identified.
North Island: Damp rotten log, 6166, on fallen caudex of tree-fern, H433, both Puaiti Bush near Rotorua, under beech, Pahautea bush, 3920, 3932, K. W. A.; Mt. Pureora, Central North Island, 3,000ft., A. L. H.; Kaimanawas, 3934, H. M. H.; on rotting, wood, Waikare-iti track, 3917, Ngamoko Track, 391, Forest Floor, Waikaremoana, 1006, rotting wood in bush Pinehaven, Wellington, 6782, on treefern caudex, bush near Wairoa, 3916, E. A. H.; on trunk of Cyathea dealbata with Bazzania, forest, Eastbourne, Wellington, 3105, N. J. Butler; on treefern caudex, Maungaroa, 3830 in part, S. Berggren, 1874.
South Island: Marlborough, J. H. McMahon; with Tylimanthus tenellus Bealey, 3685, S. Berggren; Caswell Sound, V. D. Z.; on rotten log in bush, Mt. Cargill, Dunedin, 4919, K. W. A.; Forest Floor, Tin Range, Stewart Island, 2008, W. M.
With Rhizogonium sp., bush above Musgrave Pen., Auckland Is., 9295, R. L. Oliver, 1944. This is the first recording of this species from the Subantarctic.
The type was from the Tararuas, coll. Colenso.
Also recorded from Australia and Tasmania.
Acromastigum marginatum Hodgson Spec. Nov. Text-fig. 2, figs. 10, 11.
Plantae parvae, virides, (vivae) depressae, laxe implicatae, terrestres. Caulis bis 2 cm., interdum ramosus, apice furcato forsitan, ramis divergentibus, flagellis crebris. Folia, parum obliqua patula, ovata, 0·35–0.4 mm. longa × 1·5 mm. lata, marginibus hyalinis, minute papillosis, margine ventrali convexo, dorsali. subrecto, bifido, lobis inaequalibus, ventrali triangulato, subacuto, 0.1 mm. longo, 0.1 mm lato, dorsali minimo vel obsoleto. Cellulae 10–12μ subventralibus inferis 18μ. Foliola magna, imbricata, subcircularia, triloba, lobis obtusis vel acutis. Flores ignoti.
Plants bright green when fresh, paling to fawn, loosely intricate in a depressed mat. Stems to 2 cm., branched at an angle somewhat less than a right angle, branches simple or forked, mostly bearing 1–2 flagelliform branches, to 0.5 cm. long and 0.1 mm. broad, with minute closely appressed bifid leaves. Leaves imbricate, very regular, with a narrow hyaline margin all round, narrow ovate 0.35–0.4 mm long × ca. 0.2 mm. broad, oblique, ventral margin convex, dorsal margin nearly straight; bilobed, the ventral lobe the larger, triangular, subacute, 0·1 mm. long, to 0.1 mm. broad at base (ca. 5 cells), inclined towards the apex of the stem; dorsal lobe reduced to a tooth or a crenation. Stipules imbricate, medium to comparatively large, subcircular, to 0.2 mm. wide, divided from ⅓-½ into 3 obtuse or acute lobes Cells 10–12μ, more or less in rows and fairly uniform except in basal area somewhat nearer to the ventral margin than to the dorsal,

where they may reach to 18μ. Cuticle minutely papillose showing along the margin of the leaves. No inflorescences seen.
This species is characterized by its small size, bright green imbricated leaves, with a convex oblique ventral margin, and with the dorsal lobe greatly reduced, and the comparatively large, imbricate, almost circular stipules.
The Stewart Island plant grows more compactly with shorter stems and larger cells throughout, 20μ increasing to as much as 30μ, but it is obviously the same species.

Localities: Waipoua Kauri Forest, between Dargaville and Opononi, 1,200ft., 651, V. W. Lindauer, Aug., 1939; bank of stream in forest, head of Crooked Reach, Pegasus, Stewart Island, January, 1949, 511 in part, W. M. No. 2130 Herb. Hodgson.
Type, at base of rewa-rewa trunk, Forestry Camp. Great Barrier Island, 10/4/52, 39, Ron Lloyd, No. 8433 Herb. E. A. H.

