云贵水韭 yun gui shui jiu

Plants submerged or emergent, 10-52 cm tall. Rhizome slightly 3-lobed. Microphylls 20-70 tufted, widely spreading, spirally arranged, semitransparent, green, linear, 10-60 cm, 5-10 mm wide, cross section triangular-semicircular, herbaceous, base enlarged on both sides, broadly sheathlike, membranous, concave adaxially; peripheral fibrous bundles absent. Ligules triangular, cuspidate, 1-2.5 mm. Sporangia oblong, 2-7 mm, concave, without membranous velum cover. Megaspores globose-tetrahedral, 340-430 μm in diam., proximal hemisphere rugulate-cristate with muri irregularly anastomosing, distal hemisphere cristate-reticulate. Microspores numerous, gray, powdery, 20-25 μm, smooth to granular. Microphylls Apr-May, sporangia Jul-Aug, spores mature Sep-Oct. 2n = 22*.

● Marshy soil and small ponds along streams; 1300-1900 m. Guizhou, Yunnan (Kunming, Xundian).

Specimens of Iseotes yunguiensis have long been identified as I. japonica A. Braun, but the megaspores of I. yunguiensis have cristate-reticulate ornamentation with rough ridges and are 360-450 μm in diam. and the chromosome number is 2n = 22; while megaspores of I. japonica have regular reticulate ornamentation with flattened ridges and are 390-550 μm in diam. and the chromosome number is 2n = 66.