A N F Keys
1 Annuals ......Juncus bufonius
2 Flowers widely spaced in canopy with only 1 at each fork of inflorescence .. Juncus bufonius var. bufonius [pics]
2' Flowers in dense, ± coiled cymes ......Juncus bufonius var. congestus
1' Perennial herbs with rhizomes
3 Inflorescence appearing lateral (technically always terminal), with the lowest inflorescence bract resembling a vertical continuation of the stem
4 Flowers inserted singly, with each subtended by a pair of bractlets
5 Stems densely clumped, blue green; anthers about as long as the filaments .. Juncus patens [pics]
5' Stems not densely clumped; anthers much longer than the filaments
6 Stems compressed, and plants never 100 cm tall, 1.5−3.5 mm diameter, tough and fibrous, twisted; capsules acute .. Juncus balticus var. montanus [pics]
6' Stems cylindric, 100−200 cm tall, 2−5 mm diameter, lacking leaf blades, erect and produced in a linear series from a creeping rhizome, in shade of southern oak woodland; capsules obtuse .. Juncus textilis [pics]
4' Flowers in small, headlike, bracteate clusters; hemispheric plants maritime (next to coastal shoreline) in seeps, a rigid, pincushionlike plant having skin-piercing sharp tips on the erect inflorescence bract .. Juncus acutus subsp. leopoldii [pics]
3' Inflorescence obviously terminal, with the lowest inflorescence bract spreading and not resembling a continuation of the stem
7 Leaves overlapping in 2 ranks (resembling an iris); stigmatic style branches exserted
8 Internodes of panicle 10−60 mm long; anthers much longer than filaments; capsule shorter than perianth segments .. Juncus phaeocephalus var. paniculatus [pics]
8' Internodes of panicle typically < 15 mm long; anthers shorter than filaments; capsule longer than perianth segments .. Juncus xiphioides [pics]
7' Leaves not overlapping in 2 ranks (unlike an iris), with lobes (auricles) at top of sheath; stigmatic style branches included
9 Stems with conspicuous wrinkling; leaves cylindric; heads 4−6(−10)-flowered .. Juncus dubius [pics]
9' Stems without conspicuous wrinkling; leaves flat; heads 3−5-flowered .. Juncus macrophyllus [pics]
NB. Greater effort is needed to study populations of Juncus in range. There are first of all several unresolved issues with determining correct names, including the disposition of Juncus mexicanus Willd. as it relates to J. balticus, J. bufonius var. bufonius as it relates to J. bufonius var. congestus, and J. dubius as it relates to J. rugulosus Engelm. In addition, it is still unclear whether J. torreyi Cov. or any form of J. effusus is technically in range.
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013