21. Fraxinus mandschurica Ruprecht, Bull. Phys. Math. Acad. Sci. Saint Petersburg. 15: 371. 1857.
水曲柳 shui qu liu
Fraxinus mandschurica subsp. brevipedicellata S. Z. Qu & T. C. Cui; F. nigra Marshall subsp. mandschurica (Ruprecht) S. S. Sun; F. nigra var. mandschurica (Ruprecht) Lingelsheim.
Trees to 30 m. Branchlets 4-angled, glabrous. Leaves 25-35(-40) cm; petiole 6-8 cm; axis with ridges sometimes subalate, leaflet joint brown curly hairy; leaflets 7-11(-13), subsessile; leaflet blade oblong to ovate-oblong, 5-20 × 2-5 cm, papery, adaxially glabrous or sparsely white hirsute, abaxially curly hairy along veins, especially denser at base of midrib, base cuneate to blunt, slightly oblique, margin serrulate, apex acuminate or caudate; primary veins 8-11 on each side of midrib. Panicles lateral at branches of previous year, 15-20 cm; staminate panicles congested; bisexual ones somewhat lax. Pedicel 3-5 mm in staminate panicles, longer in bisexual. Flowers polygamodioecious, appearing before leaves, without calyx and corolla. Samara oblong to obovate-lanceolate, 3-3.5(-4) cm × 6-9 mm; wing decurrent to middle or base of nutlet, obviously twisted. Fl. Apr-Jun, fr. Aug-Sep.
Sparse woods on slopes, open valleys of montane regions; 700-2100 m. Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Shaanxi, Shanxi [Japan, Korea, E Russia]
Fraxinus mandschurica is quite similar to the North American F. nigra, and most authors, including P. S. Green, prefer to treat the former as a subspecies of the latter.
Important commercial timber.