Eleocharis uniglumis

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1980, Flora Europaea. Volume 5. Alismataceae to Orchidaceae (Monocotyledones), Cambridge: Cambridge University Press : 283

12. E. uniglumis (Link) Schultes in Schultes & Schultes fil., Mantissa 2: 88 (1824)

( Scirpus uniglumis Link ; ind. E. klingei (Meinsh.) B. Fedtsch. , E. korshinskyana Zinserl. ).

Rhizome usually well developed; stems up to 60 cm, and up to 1-5 mm in diameter, firm but slender, smooth, often shiny, with 15-20 vascular bundles (not especially obvious as ridges when dry). Base of stems, rhizome and leaf-sheaths reddish-purple. Spikelet up to 12 mm, ovoid-lanceolate, dark brown, with 10-30 florets more widely spaced than in other species of the group; lowest glume empty, encircling base of spikelet. Nut coarsely punctate. Bristles 0-4(-5), often poorly developed, and rarely much longer than nut. 2n = (40-44) 46 (54-92). Saline or base-rich marshes. Most of Europe, but rare in much of the south. All except?A1 Az BI Co Lu Sb Si Tu.

Variable, but usually less so than 8. The cytological variation is to some extent correlated with variation in fruit size, and Strandhede has distinguished subsp. sterneri Strandhede , Bot. Not. 114: 433 (1961), from Öland and Gotland, with larger fruit, pollen and stomata than the type, and with 2n = 74-82. Large- fruited, high polyploid variants occur elsewhere in Europe, but apparently only sporadically. Fertile intermediates with 8(b), with various chromosome numbers between 38 and 46, occur not infrequently where the two species grow together, and are almost certainly of hybrid origin. 8(b) itself is intermediate between 8(a) and 12, and may be of ancient hybrid origin from these two widespread taxa.