Slender-flowered malaxis

Malaxis tenuis (S. Watson) Ames 1922, not Reichenbach f. 1861; Microstylis tenuis S. Watson

Plants 11–25 cm. Pseudobulbs 5–10 mm diam. Leaves 1, usually near middle of stem; blade bright green, glossy, elliptic to broadly ovate, keeled abaxially, 3–8 × 1.4–4.4 cm, base cordate to truncate, apex rounded to obtuse. Inflorescences racemes, 2.6–8 cm; floral bracts triangular, 0.8–1.2 mm, apex acute; pedicels not crowded, 7–11 mm. Flowers 13–63, resupinate, green to greenish yellow; dorsal sepal light geen, lanceolate, 4–6 × 0.9–2 mm, apex acuminate; lateral sepals distinct or sometimes connate to middle, light green edged in dark green, lanceolate, falcate, 4–6 × 0.9–2 mm, apex acuminate; petals filiform to filiform-linear, falcate, 3.5–4.5 × 0.2–0.3 mm, apex rounded; lip triangular-lanceolate, concave abaxially, 3–4.2 × 1.5–2 mm, base slightly cordate, apex long-acuminate to attenuate; disc with 2 broad green, low, longitudinal ridges; column 0.6–0.9 × 0.6–0.9 mm; pollinia orange. Capsules subhorizontal, ellipsoid, 12 × 3 mm.

Flowering summer--early fall. In humus of pine and fir forests on dry slopes; 2000 m; Ariz., N.Mex.; Mexico.