Scirpus aucklandicus (Hook.f.) Boeckeler
Isolepis aucklandica Hook. f. Fl. Antarct. 1, 1844, 88, t. 50.
I. subcucullata Bergg. in Minneskr. fisiogr. Sällsk. Lund 1878, Art. 8, 22, t. 5, f. 16–20.
I. cartilaginea R.Br. var. rigida Bergg. in Minneskr. fisiogr. Sällsk. Lund 1878, Art. 8, 23.
Scirpus muscosus Kirk in T.N.Z.I. 17, 1885, 224.
Original localities: "Lord Auckland's group and Campbell's Island; in moist places especially near the sea, also amongst grass on the hills, abundant." Lectotype: K, Auckland Is, Hooker, Nov., 1840. Also recorded from Australia and New Guinea.
Rhizomatous, forming large, turfy patches, bright green above, fuscous towards the base. Rhizome c. 0.5 mm. diam. Culms 2–5–(7) cm. × c. 0.5 mm., rigid. Lvs up to 6 per culm, us. > culms, c. 0.5 mm. wide, or often setaceous and filiform, coriac., curved; sheaths with truncate orifice, pale brown and membr., often streaked with red, rarely entirely dark red-purple. Infl. apparently lateral, of 1–(2) narrow-oblong spikelets, (1)–2–3–(4) × (0.5)–1–1.5–(2) mm., partly hidden by the enlarged base of a subtending bract up to 5 times length of spikelet. Glumes 1.5–2.5 mm. long, lanceolate, acute, deciduous, green to pale grey-brown with reddish marks, to deep red-purple, margins tapered and often pinched in at the tip below the green, thickened, ± excurrent keel. Hypog. bristles 0. Stamens 3. Style-branches 3. Nut 1–2 mm. long, slightly > 0.5 mm. wide, almost = glume, elliptical, ± trigonous with rounded angles, almost white to yellowish, or grey- to red-brown, smooth and shining but very finely reticulate, tapering towards the apiculate black tip.
DIST.: N., S., St., Ant., A., C., M.
In boggy ground; in N. and S. in mountains to 1,650 m. altitude, descending to sea level in Fiordland and Southland, and on St., A., and C.
The type sheet of Scirpus aucklandicus has 7 specimens mounted on it and the clump beside the Auckland Is label at the bottom of the sheet, marked A, has been selected as lectotype. The culms are up to 5 cm. long, and the smaller plant in Hooker's t. 50 could have been a part of this clump. The larger plant in Hooker's figure resembles another gathering on the type sheet, labelled B, with culms c. 12 cm. long. There is a label in Hooker's hand below this specimen "1639, Isolepis aucklandica, in marshy pools near the sea, Campbell Id, Dec. 1840." The specimen may be a form of S. aucklandicus, though the culms are very much longer than in any other specimen seen, or it may be S. habrus, which is known to occur on Campbell Id, but the infls are immature and no certain identification could be made.
Isolepis subcucullata Bergg. was based on specimens "in aquis stagnantibus prope flumen Waimakariri in alpibus insulae australis Novae Zelandiae". Lectotype: WELT, 20314, S. Berggren, Feb., 1874. This specimen, labelled in Berggren's hand, is very fine-lvd and rather weak; there are isotypes at WELT and K.
I. cartilaginea var. rigida Bergg. was based on specimens "in jugo Arthur's Pass, 3,000 ped. alt., in alpibus insulae australis Novae Zelandiae". Lectotype: WELT, 20316, Arthur's Pass, S. Berggren, Feb., 1874, labelled in Berggren's hand; there are isotypes at WELT and K.
Scirpus muscosus Kirk was described as a "minute species, less than one inch in height, forming moss-like patches at the head of Paterson's Inlet. Also on the Bluff Hill." WELT 20287, Paterson's Inlet, T. Kirk, no. 1035 to K, 18/12/1883 was labelled by Kirk S. aucklandicus var. muscosus.
Both S. aucklandicus and S. cernuus have 3 style-branches and 3 stamens and hence differ from all other N.Z. spp. of Sect. Isolepis, apart from S. prolifer, a more robust sp. with a distinct habit. In North and South Is S. aucklandicus is easily distinguished from S. cernuus for it occurs in mountain bogs, is very lfy, and has whitish, ± trigonous nuts, while S. cernuus is a littoral sp., almost lf-less, with grey-brown, plano-convex nuts. Though the 2 spp. can be separated in North and South Is on nut characters alone, this is not the case in Auckland and Campbell Is, where the nuts of S. aucklandicus are often red-brown, and the nuts of S. cernuus are often subtrigonous and c. 1 mm. long. However, the habitat notes on specimens collected from Auckland and Campbell Is show that the 2 spp. retain their habitat and habit differences even though S. aucklandicus occurs at sea level, for the almost lf-less S. cernuus grows in tufts on rocks or in peat on the shore just above the level of high tide, while the very lfy S. aucklandicus forms diffuse swards in boggy places further away from the shore.
Two smaller, very compact specimens, CHR 117889 from Campbell Id, and CHR 134169 from Adams Id, Auckland Is, have 2–3 stigmas and 1–2 stamens.
A chromosome count of 2n = 42 was obtained for Macquarie Id material by Moore (Bot. Notiser 113, 1960, 187).
