148 



Gramineae 



the lemma of the staminate floret awned from the base, the 

 awn geniculate, about twice as long as the lemma; callus-hairs 

 short; rachilla glabrous. May-June. Naturalized; Hok- 

 kaido, Honshu, Shikoku, Kyushu; rather common. Native of 

 Europe, now naturalized in the temperate regions. 

 Var. bulbosum (Willd.) Spenner. Avena tuberosa Gilib.; 



Avena bulbosa Willd.; Hokus avenaceus var. bulbosus 

 (Willd.) Gaudin; Avena elatior var. tuberosa (Gilib.) Aschers. 



Chorogigaya. Basal 1-3 internodes of the culms much 



swollen, as much as 10 mm. thick. Rarely cultivated in 



Japan. 



16. AVENA L. Karasu-mugi ZoKu 



Annual; leaves linear; panicles rather large, with nodding, 2- to 6-flowered, scarcely compressed spikelets; glumes 2, nearly 

 equal, membranous, 7- to 11-nerved, not prominently keeled; lemmas rather coriaceous, rounded on back, 2-toothed, the awn 

 geniculate and twisted, elongate, sometimes reduced; rachilla-joints hairy on one side; callus short; palea 2-keeled; stamens 3; 

 ovary hairy; style short; caryopsis appressed-pubescent, grooved on one side. ^About 50 species, mostly in cooler regions. 



lA. Spikelets usually 3-flowered; florets readily deciduous; rachilla and lemmas often brown-bearded, sometimes glabrous; awn stout, 



geniculate and twisted 1. A. fatua 



IB. Spikelets usually 2-flowered; florets hardly deciduous; lemmas glabrous; awn wanting or only 1 to a spikelet, erect 2, A. saliva 



1. Avena fatua L. Karasu-mugi, Cha-hiki. Annual; 

 culms 60-100 cm. long, stout; leaf-blades soft, flat, 10-25 cm. 

 long, 7-15 mm. wide; panicles 15-30 cm. long, open, loose, 

 the branches scabrous, semiverticillate; spikelets green, about 

 2.5 cm. long, 2- to 3-flowered; glumes broadly lanceolate, 

 acuminate, green, not keeled; lemma brown-bearded to gla- 

 brous, the awn elongate, strongly geniculate and twisted, dark 



brown on the lower half; callus-hairs short. June-July. 



Naturalized throughout Japan; common. Europe, w. Asia, 



and N. Africa. Now widely naturalized in all temperate re- 

 gions. 



2. Avena sativa L. Ma-karasu-mugi, Oto, Oto-mugi. 

 Annual; culms 60-100 cm. long, stout; leaf -blades linear, flat, 

 15-30 cm. long, 6-15 mm. wide; panicles open, loose, 20-30 

 cm. long; spikelets green; lemma glabrous, the awn wanting 

 or reduced. June-July. Widely cultivated in Japan. Sup- 

 posed to be derived at least in part from the preceding. 



17. HELICTOTRICHON Bess. Misayama-cha-hiki Zoku 



Perennial, mfted; leaf-blades linear; panicles open or contracted; spikelets rather large, cylindric or slightly compressed, 2- 

 to 8-flowered; rachilla bearded, disarticulating below die florets; glumes as long as the lemma or slightly longer, membranous, 

 with a broad hyaline margin, more or less keeled, 1- to 3 (-5)-nerved; lemma coriaceous with hyaline margins, 5-nerved, 

 rounded on the back, bifid, awned from about the middle, the awn long, geniculate and twisted; callus obtuse, with a tuft of 



short hairs; rachilla short-hairy on one side; palea 2-keeled; stamens 3; ovary pubescent at apex. ^Many species in Eurasia 



and Africa, few in N. America and in high mountains of the Tropics. 



1. Helictotrichon hideoi (Honda) Ohwi. Avena hideoi 

 Honda ^Misayama-cha-hiki. Rhizomes short; culms slen- 

 der, 70-90 cm. long, smooth; leaf -blades of innovation shoots 

 elongate, to 30 cm. long or more, loosely involute, 1-2 mm. 

 wide, smooth, glabrous or sparingly pilose beneath; culm- 

 blades rather flat, 5-10 cm. long, 2-3 mm. wide; sheaths pilose 

 with spreading white hairs; ligules truncate, ciliolate, 0.5-1 

 mm. long; panicles loose, nodding, rather few-flowered 6-8 

 cm. long, the branches spreading, geminate, scabrous; spike- 



lets moderately compressed, 7-9 mm. long, 2- to 3-flowered, 

 pale yellowish green, often somewhat purple-tinged; glumes 

 unequal, broadly lanceolate, acuminate, the first 4-5 mm. long, 

 1- to 3-nerved, the second 7-8 mm. long, 3-nerved; lemma 7-8 

 mm. long, acute, minutely 2-toothed, the awn exserted above 

 the middle, 12-15 mm. long, geniculate; callus-hairs 1 mm. 



long; anthers 3 mm. long. July. Grassy slopes in high 



mountains; Honshu (Shinano Prov.) ; very rare. 



18. TRISETUM Pers. Kani-tsurigusa Zoku 



Perennials, or rarely annuals; leaf-blades linear; panicles medium-sized, 2- to 6-flowered, articulate between the florets; 

 spikelets compressed; glumes unequal, membranous, keeled, acute; lemmas longer than to as long as the glumes, keeled, 

 bidentate, green to brownish, chartaceous, with hyaline margins, the awn usually elongate, from upper part of the back, 

 geniculate and twisted; callus minute, short-hairy; rachilla-joints short-hairy on the back; palea membranous, 2-keeled; stamens 

 3; ovary glabrous or pubescent at tip. About 60 species, chiefly in temperate regions. 



lA. Axis of panicle and pedicels more or less pubescent; panicle contracted, spikelike, 3-10(-12) cm. long; anthers 0.5-1 mm. long. 



1 . T. spicatum 

 IB. Axis of panicle and pedicels glabrous. 

 2A. Lemmas nearly smooth, membranous; spikelets 4-6 mm. long; panicles 5-12 cm. long, 1-1.5 cm. wide, rather spikelike; branches 



smooth; internodes of culm usually long-pubescent; anthers 0.5-0.8 mm. long 2. T. koidzumianum 



2B. Lemmas scabrous, chartaceous; spikelets 6-10 mm. long; panicles loose or contracted, 10-20 cm. long, 2-10 cm. wide. 

 3A. Anthers 0.6-1 mm. long, much shorter than the lemma; lemmas strongly scabrous, attenuate at apex into 2 short awns. 



3. T. bifidum 

 3B. Anthers 2-3 mm. long, Yz-Yi ^s long as the lemma; lemmas scabrous, minutely bidentate 4. 7*. sibiricum 



