IMG_2542Sm2
Tuft of T. germanicum



IMG_5431SmallerCrop
Young spikes of T. cespitosum;
hybrid; T. germanicum



Cespit nuts Crop 3
Ripe nuts in spikes of T. cespitosum



The genus
Trichophorum
(UK species)



To download a simple
Field-guide to the three Trichophorum taxa, click here [PDF 123 KB; opens in a new page].

Deergrasses

Rhizomatous perennial sedges, with varying dependency on damp soils, but rarely emergent from water. Two species in Britain, and their hybrid.

Growth-forms vary between very strongly, densely tufted (especially in T. germanicum) and laxer, or loosely tufted, or even with scattered stems (in T. cespitosum).

Stems extremely tough and wiry when mature, rounded in section, arising vertically, but typically then splaying out, with the outermost stems often eventually prostrate; often flexuous in some forms of T. cespitosum.

There are no non-flowering shoots, the leaves being reduced to basal sheaths on the stems, only the top sheath carrying a short blade about 1 cm long (unlike
Eleocharis, in which only blade-less sheaths occur). Note that spikelets may abort at an early stage of stem-growth, leaving a sterile ‘bare-topped’ stem which may be taken for a ‘leaf’ (and indeed substitutes for one).

The internal structure of the stem is strikingly different between the two species (see the stem
cross-sections and vertical sections pages). The hybrid is however intermediate.

The stem is terminated by a single
spikelet (for which “spike” might be a preferable term). This is small and few-flowered, each flower with a nut developing behind a glume, the lowest of which enclose and largely protect the spike. Flowers are bisexual, with three stamens, and a three-forked stigma.

The hybrid is sterile; it produces pollen (viable?) in abundance, but its nuts fail to develop.

The
perianth is reduced to a few (5-6) bristles at the base of the ovary, which do not elongate in UK species after flowering (unlike in the cottongrasses – Eriophorum – in which the bristles make the familiar head of ‘cotton’ in fruiting).

(In some populations (of
T. germanicum and the hybrid) a proportion of the flowers are proliferous (i.e. producing small plantlets).)


A third species, the boreal
T. alpinum (Scirpus hudsonianus), was known at a single site in Scotland but lost by 1813. See separate page.

Links to other pages (also accessible from the sidebar)