Part 7. JUNCACEAE 2: Juncus - Species Plantarum Programme

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SPECIES PLANTARUM — FLORA OF THE WORLD (2002)
Juncus subsect. Dregeani Novikov, Byull. Moskovsk. Obshch. Isp. Prir., Otd. Biol., 95: 121 (1990).
T: Juncus dregeanus Kunth
Perennials, caespitose or rhizomatous; stems terete to slightly compressed, with leaf blade
flat and not differentiated dorsiventrally, without septa. Flowers in compound to decompound
anthelate inflorescences of 1 to many flower heads; individual flowers in the axil of a floral
bract; bracteoles absent. Seeds with or without appendages, usually reticulate.
A section of 22 species with centres of diversity in W North America, southern Africa and
the Australasian region, extending to South America, Turkey and the Far East. It may not be
monophyletic.
1 Seeds with two appendages at least 0.2–0.4 mm long
2 Anthers c. 0.9–1.5 mm long, slightly longer than filaments; style longer
than 1 mm; auricles lacking or subacute, to 0.7 mm long 20. J. regelii
2: Anthers 1.8–2.6 mm long, usually 2–3 times as long as filaments; style
c. 0.6 mm long; auricles at least 1 mm long 21. J. howellii
1: Seeds without appendages or with a whitish apex to 0.1 mm long
3 Stamens 3; if in some flowers stamens 4–6 then triandrous flowers predominating
4 Plants dwarf, to c. 5–6 cm tall, mat-forming; leaves to 0.5 mm wide in the middle 18. J. antarcticus
4: Plants at least medium-sized, at least 10 cm tall, densely to ±loosely
caespitose, not mat-forming; leaves wider than c. 0.8 mm
5 Inner tepals acuminate to subulate-acuminate, usually 3.8–5.0 mm long
6 Style c. 0.2 mm long; stem either creeping and rooting (with leaf
rosettes 5–10 cm apart), or floating with leaf rosettes evenly
spaced along stem, or ±loosely caespitose with densely branched
short rhizome; capsule linear to lanceolate in outline 22. J. repens
6: Style 0.4–0.5 mm long; plants densely caespitose with a short rhizome,
with stem erect; leaves basal and cauline; capsule oblong-ovoid 24. J. filipendulus
5: Inner tepals obtuse, subobtuse or subacute, sometimes mucronate,
2.4–3.0 (–3.5) mm long
7 Auricles present, 0.5–3.0 mm long 25. J. marginatus
7: Auricles absent
8 Longer tepals at least 3.0 mm long; inner tepals usually slightly
shorter than the outer ones; capsule ±shorter than perianth; leaves
usually 0.8–3.0 mm wide 13. J. dregeanus
8: Longer tepals up to 2.3 (–2.8) mm long; inner tepals as long as or
longer than the outer ones; capsule ±exceeding perianth; leaves
usually 2.5–6 mm wide 19. J. planifolius
3: Stamens 6 or in a minority of flowers only 3–5
9 Capsule narrowly prismatic-pyramidal, gradually narrowing, 4.5–5.5
mm long, much exceeding perianth [Turkey] 10. J. sparganiifolius
9: Capsule ellipsoid to subglobose, retuse, truncate, obtuse or ±abruptly
narrowing, up to 4.5 mm long, shorter than or equalling or exceeding
perianth (and then apex rounded to retuse) [Not in Turkey]
10 Anthers at least 1.5–2 times as long as filaments
11 Leaves (5–) 9–13 (–15) mm wide
11: Leaves up to 5 (–6) mm wide, usually much narrower
12 Capsule usually distinctly exceeding perianth
13 Seeds c. 0.4 mm long; outer seed-coat tight, distinctly reticulate
12. J. lomatophyllus
[Pacific North America] 27. J. covillei
13: Seeds c. 0.7 mm long; outer seed-coat loose, shining, faintly
reticulate [Russian Far East and Japan] 28. J. prominens