126 Scheuchzeriaceae; Alismataceae 



usually 10-15 cm. sometimes to 25 cm. long, the pedicels 2-4 Van asiaticum (Kitag.) Ohwi. T. maritimum subsp. 



mm. long, commonly ascending; fruit 3-5 mm. long, oblong or asiaticum Kitag. Leaves often broader. ^Western part of 



ovoid-oblong. June-Oct. Saline marshes; Hokkaido, Hon- Japan. 



shu, Shikoku, Kyushu. Widely distributed in the N. 



Hemisphere and Patagonia. 



2. SCHEUCHZERIA L. Horomui-so Zoku 



Perennial herbs with short creeping rhizomes; leaves linear, sheathed at base, semi terete, somewhat flattened above, striate, the 

 sheaths becoming ligulate at apex; flowers small, bisexual, few, loosely arranged on a few-bracteate scape, pedicelled, bracteate; 

 perianth-segments 6, biseriate, persistent; stamens 6, inserted at the base of the perianth-segments, the filaments elongate, the 

 anthers linear, extrorse, basifixed; carpels 3, nearly free, l-locular, becoming patent and dehiscing ventrally; stigma sessile; seeds 

 without endosperm. One species. 



1. Scheuchzeria palustris L. Horomui-so. Glabrous, stigma oblong, sessile, inserted at the back just below the apex; 



somewhat fleshy herb; leaves mosdy basal, 8-30 cm. long, 1-2 carpels broadly ellipsoidal, inflated at maturity, 6-7 mm. long, 



mm. wide, smooth, obtuse, the ligule 3-4 mm. long, obtuse, horizontally spreading; seeds oblong, smooth, about 4 mm. 



the cauline leaves or bracts few, 7-10 cm. long, with somewhat long. June-July. Sphagnum bogs; Hokkaido, Honshu 



inflated sheaths at base; scapes 15-30 cm. long; racemes 4- to (Nikko, Oze, and nordiw.). Widely distributed in the 



8-flowered, simple, the pedicels suberect, 5-20 mm. long; cooler regions of the N. Hemisphere, 

 flowers with membranous perianth-segments 2-3 mm. long; 



Fam. 38. ALISMATACEAE OmodakaKa Waterplantain Family 



Marsh or aquatic herbs usually glabrous throughout; leaves radical, petiolate, linear to sagittate, sometimes floating, the nerves 

 converging above and connected by transverse veinlets; flowers in panicles or verticillate-racemose, actinomorphic, bracteate, 

 bisexual or unisexual (plants dioecious or monoecious) ; sepals 3, persistent; petals 3, deciduous or somewhat persistent, 

 imbricate in bud; stamens 6 or many; carpels usually many, separate, l-locular and 1-ovuled; achenes usually laterally com- 

 pressed, the embryo U-shaped, endosperm absent. Cosmopolitan with about 13 genera and nearly 100 species. 



lA. Carpels many, arranged in 1 ringlike series on a small receptacle; leaves lanceolate to elliptic, narrowed to or rounded at base (In 



ours) ; flowers bisexual; stamens 6 1- AUsma 



IB. Carpels in dense globose to oblong heads. 



2A. Flowers bisexual; stamens 6; carpels few, on a small receptacle; leaves cordate-rounded 2. Caldesia 



2B. Flowers unisexual; stamens 9 or more; carpels numerous on a globose or oblong receptacle; leaves linear to sagittate. 



3. Sagittaria 



1. ALISMA L. Saji-omodaka Zoku 



Perennials, rarely annuals; leaves long-petiolate, the blades lanceolate to elliptic, entire, with several longitudinal nerves 

 transversely connected by veinlets; scapes short or elongate; flowers small, pedicelled, in panicles; petals soon wrinkling and 

 decaying after flowering; stamens 6; carpels many, in one ringlike series on small flattened receptacles, in fruit much flattened 

 laterally, with 2 or 3 ribs on back. About 10 species in temperate and tropical regions of the world. 



lA. Leaves ovate-elliptic or ovate-oblong, rather thick, subrounded at base, not decurrent on the petiole; achenes with 2 shallow grooves 



on the back I. A. plantago-aquatica var. orientate 



1 B. Leaves lanceolate to narrowly oblong, rather thin, gradually narrowed to the petiole; achenes with a deep groove on the back. 



2. A. canaliculaium 



1. Alisma plantago-aquatica L. var. orientale G. Sam. 2. Alisma canaliculatum A. Br. & Bouche; A. plantago 



A. plantago var. parviflorum sensu auct. Japon., non Torr.; A. var. canaliculatum (A. Br. & Bouche) Miyabe & Kudo: A. 



orientale (G. Sam.) Juzep. Saji-omodaka. Glabrous plantago var. angustifolium sensu auct., non Kunth Hera- 



perennial herb with short rhizomes; leaves long-petiolate, omodaka. Similar to the preceding; leaves rather thin, lan- 



ovate-elliptic to ovate-oblong, 5-10 cm. long, 2-6 cm. wide, ceolate to narrowly oblong, 4-15 cm. long, 1-3 cm. wide, 5- 



5-7 nerved, acute or abrupdy so with an obtuse tip, sub- to 7-nerved, acuminate or acute with an obtuse tip, gradually 



rounded at base and not decurrent into the petiole; scapes narrowed to the elongate petioles; bracts acuminate; panicle- 



50-70 cm. long; panicles large, with 3 long-acuminate bracts branches usually in 3's; achenes with a deep furrow on back. 



at each node, die pedicels verticillate, 10-15 mm. long; flowers Aug.-Sept. Wet places; Hokkaido, Honshu, Shikoku, 



verticillate, the pedicels 10-15 mm. long; sepals broadly ovate, Kyushu. 



obmse, about 7-nerved, 2-2.5 mm. long; corollas white; Var. harimense Makino. A. harimense Makino Ho- 



achenes flattened, narrowly obovate, about 2 mm. long, with soba-hera-omodaka. Leaves narrower; anthers brownish 



2 shallow grooves on back. Aug.-Sept. Wet places; Hok- purple, not pale green. Honshu. 



kaido, Honshu (n. distr.). Sakhalin, Korea, Manchuria, Alisma rariflorum G. Sam. is possibly a stunted form of 



Mongolia, and e. Siberia. The species is widely distributed in No. 2. 

 the N. Hemisphere. 



