Part 6. JUNCACEAE 1: Rostkovia to Luzula - Species Plantarum ...

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SPECIES PLANTARUM — FLORA OF THE WORLD (2002)
1 Flowers solitary; anthers mucronate (if anthers not mucronate then outer
tepals at least 15 mm long); auricles never lacerate
2 Plants not cushion-forming; upper part of stem leafless; flower terminal
3 Flower bracts 2; lower bract herbaceous, conspicuously longer than
perianth; upper bract ±equalling perianth; capsule suborbicular to obovoid,
obtuse, to c. 5 mm long; seeds without conspicuous appendages 1. Rostkovia
3: Flower bracts 1 or 2, membranous, much shorter than perianth;
capsule oblong to ellipsoidal, trigonous, acuminate, at least 7 mm
long; seeds with two distinct appendages 2. Marsippospermum
2: Plants cushion-forming; upper part of stem densely covered with
leaves; flower lateral (subterminal, axillary)
4 Leaves regularly distichous; gynophore developed, elongating during
capsule ripening 5. Distichia
4: Leaves ±spirally arranged; gynophore absent
5 Flower with 1 bracteole; leaf blade with margins finely denticulate,
with apex acute but not hard nor prickly 4. Patosia
5: Flowers with 2 bracteoles; leaf blade with smooth margins, with
apex acute, hard, prickly 3. Oxychloë
1: Flowers in multi-flowered inflorescences; anthers not mucronate
(if flowers occasionally solitary then tepals shorter than 10 mm);
if anthers minutely mucronate then auricles lacerate
6 Capsule 3-seeded; leaves densely to very sparsely ciliate; flowers always
with basal bracteoles; leaf sheath closed, rarely partially dissected 6. Luzula
6: Capsule many-seeded; leaves not hairy; flowers with or without
bracteoles; leaf sheath open, rarely closed 7. Juncus
1. ROSTKOVIA
Rostkovia Desv., J. Bot. (Desvaux) 1: 324 (1809)
Type: Rostkovia magellanica (Lam.) Hook.f.
Perennial herbs, erect, glabrous. Stems leafless. Leaves all basal, spirally arranged, linear or
with reduced blade; stomata restricted to 2 narrow bands of lighter color, one on each side of
the midrib. Flower bracts 2, with the longer one erect to suberect, much exceeding the
flower, and the other ±equalling tepals. Flower terminal (pseudolateral), single, large,
hermaphrodite. Tepals castaneous-brown to dark brown; margins membranous, distally
involute. Stamens 6; anthers linear; connective with apical mucro to 0.5 mm. Ovary sessile.
Style with 3 tapering twining stigmas. Capsule subglobose, unilocular or slightly triseptate,
sessile. Seeds many, ±ovoid; appendage absent; base with a paler patch or apiculate; seedcoat
with fine longitudinal pattern, with cells narrow elongated and pointed.
Two species, one endemic to Tristan da Cunha, the other distributed in New Zealand, the
Sub-Antarctic Islands, the southernmost part of South America to Patagonia, and disjunctly
in Ecuador.
Leaves up to 1 mm wide, straight, stiff, acute; style 2.5–4.0 mm 1. R. magellanica
Leaves usually 1.2–1.7 mm wide, arcuate to circinnate, subacute-subobtuse;
style 1.5–2.0 mm 2. R. tristanensis