Taxonomic Comments | Members of Xyris are easy to identify to genus, but can be a challenge to identify species. Careful observation of a few features with a hand-lens is usually sufficient. Close attention must be paid to the flowering head, which is composed of overlapping brown scales. Immediately behind each scale are two brown "lateral sepals"; the margins of these may be feathery or irregularly lacerate (cut into narrow segments) or finely cut into short, comb-like prickles. Lateral sepals may be hidden or a bit longer than each scale. The flowers themselves are usually of little diagnostic value, other than time of flowering -- morning vs. afternoon. Seed size and ornamentation can also be useful characters, but require a dissecting scope to see well. Note also whether leaves and scapes (stems) are twisted and the color of the basal portion. All species have 2-ranked leaves, but in some species the leaves are arranged in a broad, fan-like shape. Finally, note the leaf and stem surface texture -- whether smooth of with little pale bumps. See Godfrey & Wooten (1979) for detailed descriptions and drawings. | |