Juncus

Linnaeus

Sp. Pl. 1: 325. 1753; Gen. Pl. ed. 5; 152, 1754.

Common names: Rush jonc
Etymology: classical name for the genus
Treatment appears in FNA Volume 22.
 TaxonIllustrator 
FNA22 P40 Juncus pg 215.jpegJuncus effusus
Juncus arcticus var. balticus
Juncus filiformis
Juncus drummondii
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
FNA22 P41 Juncus pg 220.jpegJuncus trifidus
Juncus gerardii
Juncus vaseyi
Juncus greenei
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
FNA22 P42 Juncus pg 222.jpegJuncus bufonius
Juncus dudleyi
Juncus confusus
Juncus tenuis
Juncus interior
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
... further results

Herbs, perennial or rarely annual, rhizomatous or cespitose. Culms round or flattened in cross-section. Cataphylls often present at culm base. Leaves: sheaths open; blade flat, channeled, ensiform or terete, sometimes septate, margins involute. Inflorescences terminal or pseudoaxillary, monochasia or dichasia, usually with monochasial branches, cymes or 1–many heads in racemes or panicles; bracteoles 2 or absent. Flowers: tepals (4–) 6 in 2 whorls; stamens (2–) 3–6. Capsules 1-locular or 3-locular, septicidal. Seeds many, ellipsoid to ovoid, sometimes tailed.

Distribution

Worldwide except Antarctica

Discussion

Species ca. 300 (95 in the flora).

Key

1 Flowers borne singly; bracteoles present (except J. pelocarpus, J. subtilis). > 2
1 Flowers in heads; bracteoles absent. > 4
2 Inflorescences appearing lateral, inflorescence bract terete, erect, appearing to be continuation of culm; basal leaves bladeless, cauline leaves absent Juncus subg. Genuini
2 Inflorescences appearing terminal, inflorescence bract erect or ascending, flat, involute or terete; basal leaves (at least some) usually with blade, cauline leaves present or absent. > 3
3 Leaves terete, septate; capsules beaked Juncus subg. Septati
3 Leaves flat, involute or terete, not septate; capsule rarely beaked Juncus subg. Poiophylli
4 Leaves flat or ensiform. > 5
4 Leaves terete or compressed. > 6
5 Leaves ensiform, imperfectly septate Juncus subg. Ensifolii
5 Leaves flat, not septate Juncus subg. Graminifolii
6 Capsules large; seeds large, long tailed; leaves not noticeably septate Juncus subg. Alpini
6 Capsules smaller; seeds not tailed or if tailed not long; leaves septate or not. > 7
7 Leaves not septate; plants halophytic Juncus subg. Juncus
7 Leaves septate; plants usually of fresh water habitats Juncus subg. Septati
... more about "Juncus"
persistent +
Ralph E. Brooks* +  and Steven E. Clemants* +
Linnaeus +
terete;ensiform;channeled;flat +
Rush +  and jonc +
flattened +  and round +
Worldwide except Antarctica +
classical name for the genus +
arranged +  and cluster +
headlike +
pseudoaxillary +  and terminal +
3 +  and 1 +
green;brown or purplish black +
persistent +
parietal +  and axile +
engelmann1866a +  and hermann1975a +
tailed;ellipsoid;ovoid +
green;brown or purplish black +
persistent +
3 +  and 6 +
generally longer +
Juncaceae +
annual +  and perennial +
herb +  and cespitose +