Juncus hondurensis, J. Prockow. Flowers, 2020

Proćków, Jarosław, 2020, Juncus hondurensis (Juncaceae), an endemic rush species new from Honduras, Phytotaxa 439 (1), pp. 93-101 : 99-100

Key to the separation of Juncus hondurensis from other Neotropical species of Juncus sect. Ozophyllum

1. Rhizome stoloniform and/or ascending branching............................................................................................................................... ................................... J. stipulatus Nees & Meyen in Meyen (1843: 126), J. nodosus Linnaeus (1762: 466) , J. ebracteatus Meyer

- Rhizome short creeping, long creeping, or densely branching .........................................................................................................2.

2. Plants forming loose colonies, rhizome creeping with short internodes; cataphylls present and usually conspicuous....................... ...................................................................................................................................................... J. liebmannii Macbride , J. andinus Balslev , J. echinocephalus Balslev (1979: 37) , J. ustulatus Buchenau (1879: 401) , J. austrobrasiliensis Balslev , J. subulitepalus Balslev (1996: 136) , J. densiflorus Humboldt, Bonpland & Kunth (1816: 238) , J. micranthus Schrader ex Meyer (1823: 31)

- Plants cespitose, rhizome densely branching and not creeping; cataphylls absent or inconspicuous...............................................3.

3. Capsule longer than tepals.................................................................................................................................................................4.

- Capsule equalling or shorter than the tepals......................................................................................................................................8.

4. Capsule extended into a 1–2 mm long beak, terete ........................................................................................... J. ebracteatus Meyer

- Capsule acute, trigonous or apically rounded and apiculate .............................................................................................................5.

5. Capsule 4–6 mm long; plants to 150 cm high ...................................................................................................................................... ......................... J. diffusissimus Buckley (1862: 9) , J. chiapasensis Balslev (1988: 379) , J. guadeloupensis Buchenau (1900: 496)

- Capsule 2.5–4 mm long; plants 15–50(–70) cm tall..........................................................................................................................6.

6. Capsule narrowly ellipsoid ( Mexico and N America), light brown, stamens 3 .................................................................... J. debilis

- Capsule broadly ovoid or broadly ellipsoid to elongate-spherical, stamens 6 ..................................................................................7.

7. Seeds 25-striate, ovoid, 0.45–0.6 × 0.24–0.26 mm; capsule broadly ovoid, dark castaneous to black .......................... J. articulatus

- Seeds 14–16-striate, narrowly to broadly ellipsoid, (0.3–)0.4–0.44 × 0.16–0.21 mm; capsule broadly ellipsoid to elongate-spherical, light brown at the base and up to the middle, and dark brown at the apex (sometimes also lighter there).......................................... ..................................................................................................................................................................................... J. hondurensis

8. Plants <10 cm tall ................................................................................................................................................................................. .......................... J. stipulatus Nees & Meyen in Meyen (1843: 126), J. breviculmis Balslev (1983: 303) , J. fuscocapitatus Balslev

- Plants> 10 cm tall ..............................................................................................................................................................................9.

9. Flower heads 2–3-flowered ........................................................................................................................... J. liebmannii Macbride

- Flower heads many-flowered. .........................................................................................................................................................10.

10. Foliar leaves and lower inflorescence bract overtopping mature inflorescence............................ J. breviculmis Balslev (1983: 303)

- Mature inflorescence overtopping foliar leaves and lower inflorescence bract ..............................................................................11.

11. Seeds 0.7–0.9 mm long; capsule 2.9–4.4 mm long.................... J. ecuadoriensis Balslev in Harling, Sparre & Eliasson (1979: 36)

- Seeds <0.5 mm long; capsule <3.5 mm long. .................................................................................................................................12.

12. Inflorescence congested into 1(–2) dark castaneous heads; lower inflorescence bract scale-like, about as long as the flower head.. ...................................................................................................................................................................... J. fuscocapitatus Balslev

- Inflorescence with open branching and several flower heads; lower inflorescence bract well-developed.....................................13.

13. Ultimate peduncles> 0.45 mm diam., tepals rigid...........................................................................................................................14.

- Ultimate peduncles <0.4 mm diam..................................................................................................................................................15.

14. Tepals 3.0– 4.5 mm long, subequal, acuminate; filaments (0.6–)1.0– 1.2 mm long.......................................... J. pallescens Lamarck

- Tepals outer ones 2.5–3(–3.3) mm long, inner ones 2.3–2.6(–2.8) mm long, inner tepals shorter than outer ones (sometimes only slightly), or rarely longer, acute; filaments (0.65–)0.75–0.85(–0.9) mm long............................................................ J. hondurensis

15. Tepals rigid; capsule broadly ellipsoid to elongate-spherical, more cylindrical at the bottom (in x.s.), and three-lobed in the upper part (in x.s.), apically rounded and apiculate; stamens 6............................................................................................. J. hondurensis

- Tepals soft, capsule different ...........................................................................................................................................................16.

16. Capsule trigonous, valves inflexed along the margins at maturity; stamens 3 (N America to Honduras) ........................................... ........................................................................................................................................................................ J. acuminatus Michaux

- Capsule round, valves inflexed at the apex at maturity; stamens 6 (S America to C Mexico) ............................................................ ................................................................................................................................. J. microcephalus Humboldt, Bonpland & Kunth