The leaves of Luzula are primarily basal; cauline leaves are usually reduced. Luzula species have diffuse centromeres and small chromosomes. That has resulted in much confusion in interpretation and reporting of chromosome counts. No attempt has been made to include reported counts that could not reasonably be verified by the author.
Excluded species: Luzula sudetica (Willdenow) de Candolle. Although reports of this European species appear frequently in the North American literature, I have seen no specimens that confirm its presence. No chromosome counts are published for North American material. Since this species has a distinct cytotype, 2n = 48 (H. Nordenskiöld 1956), it should not be difficult to verify on this basis.
Fls generally prophyllate, as in spp. of Juncus; perianth as in Juncus; ovary and loculicidal capsule unilocular; ovules and seeds 3, basal; infl varying from open, lax, and subumbellately paniculiform to composed of several compact spikes or heads, these sometimes clustered to form a secondary spike or head; lvs with closed sheath and flat, grass-like blade provided (at least when young) with some long, loose hairs along the margins, especially at the throat. 75, mainly in temp. and cool parts of the N. Hemisphere.
Spp. 3-7 belong to a circumboreal pillar-complex, perhaps better treated with fewer binomials and more trinomials, but the taxonomy and nomenclature not yet clear.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.