Flower:

One to 7 spikelets (flower clusters) on slender stalks of varying lengths all arising from the tip of the stem, usually an open cluster, sometimes more compact. The lowest spikelet has a scale-like bract at the base, its midrib with a bristle-like or leaf-like extension that usually over-tops the spikelet. Spikelets are erect to ascending, lance-shaped in outline, red-brown, 3 to 5 mm long (less than ¼ inch), and few-flowered.

Flowers are perfect (both male and female parts), each with 1 or 2 stamens, a 3-parted style, and subtended by a scale. Scales are 1.5 to 2 mm long, egg-shaped, blunt to pointed at the tip, hairless or minutely hairy near the tip, red-brown with a prominent green midrib that rarely extends slightly at the tip.

Leaves and stems:

Leaves are basal and alternate on the lower stem, erect to ascending to spreading, hairless, wiry with rolled-in edges (involute), up .5 mm wide, up to a third as long as the flowering stem. Sheaths are prominently ribbed on the back. Stems are also thread-like, erect to ascending, unbranched, 3-sided in cross-section, hairless, green, and multiple from the base forming clumps, the clump of stems often of widely varying lengths.

Fruit:

Achenes (seeds) are about 1 mm long, yellowish to pale brown, 3-sided in cross-section, urn-shaped in outline, the surface covered in cross-wrinkles, and with a tiny cap-like appendage (tubercle) at the tip, and lacking any bristles around the base.

Notes:

Bulbostylis capillaris is an occasional sedge of dry, sandy or rocky soils. In Minnesota, it is most often found on sandy beaches or dunes and in rock outcrops, growing in the thin soil of cracks and shallow depressions. When stems have a single spikelet it may be mistaken for an Eleocharis species, which lack any bladed leaves and usually have bristles around the base of the achenes. It may also be mistaken for Fimbristylis autumnalis, a more rare species which has broader, flat leaves, flattened stems and spikelet stalks, the spikelet clusters are more numerous, often in compound (branched) clusters, and achenes are rather smaller, are variably warty especially around the base, and lack a tubercle.