The Botany of Iceland - 01.12.1942, Qupperneq 193

THE PTERIDOPHYTA AND SPERMATOPHYTA OF ICELAND
191
Icelandic: Þráðsef. Danish: Traadstænglet Siv. English: Thread Rush.
Seems to be common throughout the lowland ; not yet recorded from the central
highland. It is often the dominating species in somewhat moist depressions, and is
valued as a good fodder plant.
Life-form: G. (Rhizome Geophyte).
In moderately moist moors, in sandy and boggy places; borders of lakes.
Flor. VI—VII; fr. mat. VII—VIII.
Max. height: 58 cm; average: 25 cm (fruit. stem average: 20 cm).
Geogr. area: Am.: From Newfoundland to Alaska, south to Oregon, Utah; S. Am.:
Patagonia.—Greenl. : W. 60°—62°3'. E. 60°-—61°43'.—Eur.: E.S.; northern, western
and central Europe, Pyrenees, Caucasus,-—Asia: Siberia southward to northern
Mongolia, Amur, Kamchatka, Honshu. Asia Minor.
Juncus Gerardi Lois.
Juncus bulbosus, K. & M., 1770, p. 206.—J. compressus Jacq., Lindsay, 1861, p. 32.
—J. Gerardi Lois., Babington, 1871, p. 332.
This species is recorded by several of the older authors, from König & Miiller
to Babington ; there are, however, no specimens in evidence, and it may be safe to
exclude it from the Icelandic flora.
Juncus Jacquini Linn.
Recorded by Preyer & Zirkel, 1862, p. 356.
This is a species from the Alps and Karpathians and a plant very unlikely to
grow in Iceland. (Cp. also Babington, 1871, p. 333). It is perhaps a mistake for
J. castaneus which may very well resemble this plant.
142. Juncus nodulosus Wahlenbg., Fl. Upsal., 1820, p. 114.
J. alþinus Vill., Babington, 1871, p. 332.—Gronlund, Isl. Fl., 1881, p. 100.—
Stefánsson, Fl. ísl., ed. 1, 1901, p. 24,—Ibid., ed. 2, 1924, p. 27,—C.H.O.,
Fl. arct., 1902, p. 24,—O. & Gr., 1934, p. 44.
Flora Dan. tab. 2171.
Icelandic: Mýrasef. Danish : Sodfarvet Siv. English : Alpine Rush.
In Iceland this species is represented by different forms, at least three are
distinguished by B. Lindquist, in Botan. Notiser, 1932, p. 313 et seq.
1. var. alþestris (C. J. Hartman) C. Hartman, the commonest form.
la var. alþestris (C. J. Hartman) C. Hartman f. uniceþs Krok & Lagerstedt, rare.
2. var. Marschallii (Pugsley) Lindquist, fairly common.
3. var. rariflorus (Fr.) C. J. Hartman, very rare.
Common in all parts in the lowland ; on the central plateau recorded only from
Þorlákslindir (D. 14).
Life-form: H.
In bogs; on wet clayey ground, along brooks, near warm or cold springs.
Flor. VII—VIII; fr. mat. VIII—IX.
Max. height: 35 cm; average: 16 cm.
Geogr. area: Am. : Arctic Sea coast, southward to Brit. Columbia and Nebraska.—
Grcenl.: W. 60°40'—61°2' and 64°22'.—Eur.: S.; northern and central Europe ;
Caucasus.—Asia: Siberia.