Flora of New Zealand Series

Juncus magellanicus Lam. Encycl.  3,  1789,  266.

R. sphaerocarpa Desv. in J. Bot. (société de botanistes)  1,  1808,  327, t. 12, f. 2.

Type locality: Straits of Magellan, Tierra del Fuego. Type: P?, Commerson.

Plants in small tufts, 5–20–(40) cm. tall. Rhizome 1–2 mm. diam., very shortly creeping, tufts < 4 cm. apart. Stems ∞, c. 0.5 mm. diam., rigid, often enclosed for half their length by the lf-sheaths; basal bracts ∞, mucronulate, often becoming fibrous. Lvs us. > stems, us. < 1 mm. wide, lamina in plants from Subantarctic Is concave on the adaxial surface just above the lf-sheath but distally becoming plano-convex or almost terete with a very shallow abaxial furrow, lamina in South Id plants flattened, rigid, bright green, polished, tips rigid; sheaths light cinnamon-brown, shining, with 2 obtuse auricles. Fls 5–10 mm. long, lower subtending bract lf-like, rigid, 1–3.5 cm. long, the upper membr., c. = tepals. Tepals lanceolate, acute, red-brown with paler membr. margins. Stamens 6, < tepals; anthers ± = filaments, connective apiculate. Capsule 3.5–10.5 × 2–7 mm., slightly > tepals, ellipsoid, hard, smooth and shining, chestnut-brown, mucronate, dehiscing loculicidally towards the apex. Seeds 1.2–2 × 0.6–1.2 mm., obovoid, shining, dark brown almost black, paler towards the base, not tailed.

DIST.: S. Old Man Range, Otago and Takahe Valley, Fiordland. A. Common on higher ridges in damp situations. C. In scattered patches on higher ridges such as Mt Honey, Mt Lyall and Mt Azimuth.

Also in southern S. America, Falkland Is and S. Georgia.

FL. 12–2. FT. 2–4.

R. sphaerocarpa Desv. was based on J. magellanicus Lam.

Specimens from South Id have smaller capsules (3.5–6 × 2–3 mm.), smaller seeds (1.2–1.5 × 0.6–0.9 mm.) and flatter lvs than specimens from the Subantarctic Is (capsules 6–10.5 × 3–7 mm.; seeds 1.4–2 × 0.7–1.2 mm.). Parallel differences may also be found in specimens from southern South America; plants from Southern Chile and Tierra del Fuego have small capsules and seeds and thickly V-shaped lvs, while plants from the Falkland Is and South Georgia have larger capsules and seeds and their lvs are plano-convex in transverse section.

Armstrong (T.N.Z.I. 12, 1880, 344) listed R. magellanica as abundant on Banks Peninsula, but there is no herbarium specimen to support this. A specimen at CANTY labelled R. magellanica, Browning Pass, J. B. Armstrong, 1868, was redetermined by A. Wall as R. gracilis. There are no later records of R. magellanica for Canterbury.

Burrows (N.Z. J. Bot. 5, 1967, 443–6) discussed South Id records for R. magellanica and he recorded the sp. as "quite common" in Takahe Valley, Fiordland.