C^TERACEAE 



199 



nual, resembling No. 18; culms 20-60 cm. long; spLkelets lin- 

 ear, compressed, 7-12 mm. long, 1.5-2 mm. wide, reddish 

 brown; scales broadly obovate, 1.5 mm. long, rounded, the 

 midrib green, excurrent as a slightly recurved awnlike mucro. 



Aug.-Oct. Cultivated fields and waste grounds; Honshu, 



Shikoku, Kyushu; rather common. Korea, Ussuri, Amur, 



China, and Formosa. 



20. Cyperus compressus L. Kugu-gayatsuri. An- 

 nual; culms tufted, 10^0 cm. long; leaves 1-3 mm. wide; in- 

 florescence simple, to 10 cm. long, with 1-5 ascending rays 

 about 5 cm. long, rarely the rays abbreviated and the inflores- 

 cence capitate, the bracts 2 or 3, longer dian the inflorescence; 

 spikelets linear, 1-2.5 cm. long, 2.5-3 nnm. wide, strongly com- 

 pressed, pale and somewhat yellowish at maturity, slightly 

 lustrous; scales broadly ovate, 3-3.5 mm. long, obtuse, incon- 

 spicuously several-nerved, the keel thick, green, with a slightly 

 recurved awnlike mucro about 0.7 mm. long at ape.x; achenes 



1/3 as long as the scale, lustrous, 3-angled; srigmas 3. Aug. 



-Oct. Waste grounds, roadsides, seashores, quite common; 



Honshu (Kanto Distr. and westw.), Shikoku, Kyushu. 



Ryukyus, Formosa, China, India, and throughout the Tropics. 



21. Cyperus difformis L. Tama-cayatsuri. Soft an- 

 nual; culms tufted, 15-60 cm. long; leaves 2-5 mm. wide; in- 

 florescence a simple or compound corymb to 7 cm. across, with 

 1-6 rays to 5 cm. long, or sometimes capitate, the bracts 2 or 

 3, the lowest longer than the inflorescence; spikelets very 

 densely disposed in subglobose spikes, linear, 3-10 mm. long, 

 1 mm. wide, compressed or slightly turgid, dark reddish 

 brown to pale green, dull; scales obovate-orbicular, 0.5 mm. 

 long, entire, rounded-emarginate, the keel rather acute, green; 

 achenes nearly as long as the scale, 3-angled, pale, obovate; 



stigmas 3. Aug.-Oct. Common in wet places or in paddy 



fields; Hokkaido, Honshu, Shikoku, Kyushu. Ryukyus, 



Formosa, Korea, China, India, Malaysia, Australia, s. Europe, 

 and Africa. 



22. Cyperus haspan L. Ko-aze-gayatsuri, Mizu-ha- 

 NABi. Rhizomes elongate, slender; culms solitary, nearly 

 naked, 20-60 cm. long; leaves flaccid, short, often bladeless, 

 2-6 cm. long; corymbs compound or simple, to 15 cm. across, 

 with many spreading slender rays, the bracts 1 or 2, leaflike, 

 longer or shorter than the inflorescence; spikelets digitate in 

 groups of 4 or 5, linear, flat, 5-15 mm. long, 1.5-2 mm. wide, 

 sanguineous; scales oblong to narrowly so, about 1.5 mm. long, 

 emarginate and mucronulate with the green midrib ending as 

 an erect slighdy excurrent mucro; achenes 1/3 as long as the 



scale, white, 3-angled, elliptic; sdgmas 3. Aug.-Oct. 



Swampy places and rice paddies; Honshu, Shikoku, Kyushu. 



Ryukyus, Formosa, China, Indochina, India, Malaysia, and 



Australia. 



23. Cyperus tenuispica Steud. C. flavidus sensu auct. 



plur., non Retz.; C. pseudohaspan Makino Hime-gaya- 



TsuRi, Mizu-HANABi. Closcly akin to the preceding, but 

 rhizomes absent; culms tufted, flaccid; leaves 2-4 mm. wide; 

 spikelets 3-8 mm. long, 1-1.5 mm. wide; scales oblong to ob- 

 long-lanceolate, nearly 1 mm. long, obtuse and emarginate, 

 with a green keel excurrent as a slightly recur\'ed mucro; 

 achenes 2/5-1/2 as long as the scale, white, broadly obovate, 



obtusely 3-angled; stigmas 3. Aug.-Nov. Wet places; 



Honshu, Shikoku, Kyushu. Ryukyus, Formosa, s. Korea, 



China, Indochina, India, Malaysia, tropical Australia, and 

 tropical Africa. 



24. Cyperus hakonensis Fr. & Sav. C. trinervis var. 



ftaccidus Kuekenth., pro parte Hina-gayatsuri. Small 



green annual; culms flaccid, tufted, 5-25 cm. long; leaves usu- 

 ally reduced to short-bladed or bladeless hyaline sheaths; 

 corymbs simple or subcompound, rather loose, with 3-5 short 

 rays, rarely to 10 cm. long, the bract solitary, decurrent on the 

 culm, nearly as long as the inflorescence; spikelets digitate, in 

 groups of 2-6, strongly flattened, light green, 5-12 mm. long, 

 2 mm. wide; scales spreading, broadly ovate, 1 mm. long, the 

 keel conspicuous, more or less winglike, excurrent at apex as a 

 recurved awn 1/5-1/4 as long as the scale; achene 1/3 as long 

 as the scale (including the awn), broadly obovate, 3-angled, 



light yellow; stigmas 3. Aug.-Oct. Wet grassy places in 



low grounds; Honshu, Shikoku, Kyushu. Korea and 



China. 



25. Cyperus niigatensis Ohwi. Niigata-cayatsuri. 

 Annual; culms tufted, about 10 cm. long; leaves 1-2 mm. 

 wide; inflorescence capitate, globular, 1-1.5 cm. wide, the 

 bracts 4 or 5, spreading, to 10 cm. long; spikelets numerous in 

 the head, ovate, 2-3 mm. long, 1.5 mm. wide, slighdy flat- 

 tened, obtuse, yellowish green; scales ascending, 2-ranked, 

 ovate-orbicular, obtuse, entire, hyaline, 5- to 7-nerved; achenes 

 1/2-2/3 as long as the scale, obovate, brownish, obtusely 

 angled, lunate in cross section, the midrib sometimes slightly 

 conspicuous; stigmas 2 or 3. Honshu (Niigata). 



26. Cyperus nipponicus Fr. & Sav. var. nipponicus. 

 C. michelianus var. nipponicus (Fr. & Sav.) Kuekenth.; Jun- 

 cellus nipponicus (Fr. & Sav.) C. B. Clarke; /. pygmaeus sensu 

 auct. Japon., pro parte, non C. B. Clarke; Dichostylis nipponica 



(Fr. & Sav.) Palla Ao-gayatsuri, O-tama-gayatsuri. Soft 



green annual; culms 5-25 cm. long; leaves 1-2.5 mm. wide; 

 inflorescence capitate, globose, dense, 1-2.5 cm. across, occa- 

 sionally umbelliform with 1-5 rays to 5 cm. long, the bracts 

 leaflike; spikelets slightly flattened, lanceolate or narrowly 

 ovate, 3-7 mm. long, 1.5-2 mm. wide, pale green; scales 2- 

 ranked, dense, ovate, 1.7-2 mm. long, several-nerved, hyaline, 

 obtuse with a broad tip; achenes 2/5-1/2 as long as the scale, 

 obovate to elliptic, lunate in cross section, obtusely angled, 



light brown; stigmas 2 or 3. Aug.-Oct. Honshu, Shikoku, 



Kyushu. Korea, China, and Manchuria. 



Var. spiralis Ohwi. Scirpus stauntonii C. B. Clarke; C. 

 stauntonii (C. B. Clarke) Ohwi O-shiro-gayatsuri. Spike- 

 lets not flattened, obscurely angled; scales spirally arranged. 

 Honshu, Shikoku. China. 



27. Cyperus extremiorientalis Ohwi. funcellus pyg- 

 maeus sensu auct. Japon., non C. B. Clarke Hime-ao-gaya- 



TsuRi. Soft green annual; culms 3-15 cm. long; leaves 1-2 

 mm. wide; inflorescence capitate, globose, 1-1.5 cm. in di- 

 ameter, densely many-spiculose, the bracts leaflike, longer than 

 the inflorescence; spikelets mostly flat, lanceolate to broadly so, 

 2-6 mm. long, 1-1.3 mm. wide, acute, pale green; scales 

 broadly lanceolate, 1.5-2 mm. long, 2-ranked, hyaline, faintly 

 3- to 5-ner\'ed, very obtuse and mucronate, the mucro ex- 

 tremely short, erect, sparsely spinulose or smooth; achenes 

 1/2-2/3 as long as the scale, narrowly oblong, planconvex, 

 light brown, acutely angled; srigmas 2. Aug.-Oct. Hon- 

 shu, Shikoku. 



28. Cyperus pacificus (Ohwi) Ohwi. C. michelianus 

 sensu auct. Japon., non Link; Scirpus michelianus sensu auct. 

 Japon., non Roem. & Schult.; C. michelianus var. pacificus 

 Ohwi; Isolepis micheliana sensu auct. Japon., non Roem. & 

 Schult. Shiro-gayatsuri. Soft green annual; culms 3- 



