Part 7. JUNCACEAE 2: Juncus - Species Plantarum Programme

4
SPECIES PLANTARUM — FLORA OF THE WORLD (2002)
KEY TO SUBGENERA AND SECTIONS
1 Inflorescence racemose, with the pair of floral bracteoles absent; flowers
usually in heads or clusters, rarely borne ±singly (subg. Juncus)
2 Leaves terete, stem-like, pungent, basal, not septate; vascular bundles
scattered over most of T.S.; lower bract apparently forming a
prolongation of stem sect. 1. Juncus (p. 5)
2: Leaves flat, compressed, canaliculate or if terete then usually septate, not
stem-like, basal or cauline; vascular bundles usually in subepidermal
position; lower bract usually not appearing as a stem prolongation
3 Leaves unitubulose or pluritubulose, perfectly septate; if pluritubulose
(not bitubulose) and imperfectly septate, then terete, or flattened but
then not arranged perpendicular to stem sect. 6. Ozophyllum (p. 151)
3: Leaves flat or with raised margins, not septate, or bitubulose and
septate, or laterally compressed and pluritubulose and imperfectly
septate (then arranged perpendicular to stem), if unitubulose and
perfectly septate then with anthers distinctly exserted
4 Annuals sect. 3. Caespitosi (p. 57)
4: Perennials
5 Anthers distinctly to at least partly exserted from perianth in later
stages of flowering sect. 4. Stygiopsis (p. 74)
5: Anthers not exserted
6 Most of inflorescence not fertile, of golden-coloured feather-like
branchlets
6: Inflorescence usually fully fertile, not of the above appearance
sect. 4. Stygiopsis
(J. ochraceus) (p. 74)
7 Leaves laterally compressed, pluritubulose, imperfectly septate,
arranged perpendicular to stem sect. 5. Iridifolii (p. 135)
7: Leaves dorsiventrally compressed or ±canaliculate, not septate,
arranged with adaxial flat side facing the stem
8 Seeds with two distinct appendages [Sino-Himalayan region] sect. 4. Stygiopsis (p. 74)
8: Seeds without appendages, or if appendages present then W
North America sect. 2. Graminifolii (p. 5)
1: Inflorescence cymose, with a pair of floral bracteoles present below each
flower; flowers usually borne singly or in loose groups (subg. Agathryon
[subg. Poiophylli])
9 Annuals sect. 7. Tenageia*
9: Perennials
10 Inflorescence seemingly lateral (pseudolateral); lower inflorescence
bract terete, erect, seeming to be a continuation of stem; basal leaves
bladeless; cauline leaves ±absent; sterile shoots terete, stem-like
10: Inflorescence obviously terminal; lower bract flat, canaliculate or terete,
not appearing as a continuation of stem; at least some basal or sub-basal
leaves with a well developed blade; sterile shoots not stem-like
11 Cauline leaves terete; leaf epidermal cells of the same size; pith of
sect. 9. Juncotypus*
astericiform cells
11: Cauline and/or basal leaves flat to canaliculate; leaf blade with at
least some cells of adaxial epidermis enlarged, and margins with thin
sclerenchymatous strands); inner part of leaves of chlorenchyma,
sect. 10. Forskalina*
rarely with air channels, not of astericiform cells sect. 8. Steirochloa *
* Sections included in Part II of the Juncus treatment.