Trianoptiles capensis Harv.

This grass-like annual reaches 250 mm high and many of the aerial inflorescences project beyond the leaves. The greenish aerial spikelets form lax clusters on branches that arise in the axils of leaves. Most of the bisexual spikelets have five bracts and the perianth scale terminates in three bristles. The ovary is not stalked but terminates into a beak at the tip. The smoothly ribbed fruit is divided into three fused parts, the cell outlines clearly visible. The basal fruit is often found away from the central axis of the plant, as it tends to drift by intercalary growth.

T. capensis has a range extending from Ceres to the Cape Peninsula to Knysna.

Trianoptiles solitaria (C.B. Clarke) Levyns ( Subterranean Cape sedge)

The ovary is 3-angular with an almost hairless beak-like tip. The fruit is about 2 mm long with a densely pitted surface.
The basal spikelet has an extensive sheathing bract around the style. The fruits ripen in the axils of the leaves close to the stems, unlike T. capensis where some intercalary growth occurs and the fruits ripen away from the main axis of the plant. This gives a superficial resemblance to the genus of fern Isoetes.

See more below.

Trianoptiles stipitata Levyns

Reaching 20 cm in height, this species resembles T. capensis in its growth form, although the reproductive stuctures differ slightly. It also differs from T. capensis in that its perianth scales are larger, hairier on the outer surface, and also with a tuft of hairs on the inner surface below the bristles.  It has a stalked ovary, and no cell outlines are visible at the intersections of the faces.

The species has scattered collections from the Calvinia District, Vanrhynsdorp, the Cape Peninsula and Bain's Kloof, although these seem to be localised population.