Juncus subg. Genuini in Flora of North America @ efloras.org

1a. Juncus subg. Genuini Buchenau, Abhandlungen herausgegeben vom naturwissenschaftlichen Vereine zu Bremen. 4: 406. 1875.

Juncus sect. Genuini (Buchenau) Dumortier; Juncus sect. Juncotypus Dumortier; Juncus subg. Juncotypus (Dumortier) Kreczetowicz & Gontscharow

Herbs, perennial, rhizomatous. Culms terete. Leaves basal; blade usually absent, rarely present (J. hallii and J. parryi), if present terete, channeled, not septate. Inflorescences lateral cymes, sympodial; bracts erect, terete, appearing to be continuation of culms; bracteoles 2, at base of perianth. Flowers borne singly, not in heads. Capsules 3-locular. Seeds usually not tailed.

Species ca. 25 (11 in the flora): worldwide.

SELECTED REFERENCES

Fernald, M. L. and K. M. Wiegand. 1910. The North American variation of Juncus effusus. Rhodora 12: 81--93. Hamet-Ahti, L. 1980. The Juncus effusus aggregate in eastern North America. Ann. Bot. Fennici 17: 183--191. Stace, C. A. 1970. Anatomy and taxonomy in Juncus subgenus Genuini. Bot. J. Linn. Soc. 63(suppl. 11): 75--81.

1 Flowers 1--3(--5); seeds tailed. (2)

+ Flowers more than 5. (4)

2 (1) Leaf blade reduced to bristle 4 Juncus drummondii

+ Leaf blade well developed. (3)

3 (2) Perianth 6--9 mm; capsules oblong, acute 2 Juncus parryi

+ Perianth 4--5 mm; capsules ovoid, retuse 3 Juncus hallii

4 (1) Culms well spaced along sparingly branched creeping rhizomes. (5)

+ Culms tufted on short, densely branching rhizomes. (8)

5 (4) Anthers shorter than filaments; tepals greenish; capsules green to light brown 5 Juncus filiformis

+ Anthers equal to or longer than filaments. (6)

6 (5) Fruits acute. (7)

+ Fruits obtuse 11 Juncus textilis

7 (6) Perianth usually 3--6 mm 9 Juncus arcticus

+ Perianth (5--)6--8 mm 10 Juncus lesueurii

8 (4) Stamens 3 7 Juncus effusus

+ Stamens 6. (9)

9 (8) Plants cespitose, stooling; capsules 3--4 mm 6 Juncus inflexus

+ Plants cespitose, not stooling; capsules less than 3 mm. (10)

10 (9) Perianth much shorter than capsule; seeds 0.7--1 mm 1 Juncus gymnocarpus

+ Perianth equal to or exceeding capsule; seeds 0.4--0.5 mm 8 Juncus patens