162 Gramineae 



IIB. Glumes and lemmas entire, membranous, acute to obtuse; innovation-shoots not elongate. 

 12A. Lemmas not cobwebby at the base. 



13A. Plant estoloniferous; culms erect, slender but not soft; anthers 1.2—2 mm. long; panicles erect 11. P. glauca 



13B. Plant short-stoloniferous; culms ascending at base, rather stout and soft; anthers 1.8-2.2 mm. long, panicles nodding. 



12. P. hayachinensis 

 12B. Lemmas cobwebby on the callus. 



14A. Spikelets glaucescent or purplish; lemmas of the lower florets usually more than 4 mm. long. 



15A. Glumes lanceolate, acuminate, the lateral nerves prominent, almost reaching the tip of the glumes; anthers 



1.5-2.2 mm. long 13. P. macrocalyx 



15B. Glumes broadly lanceolate, the lateral nerves about % the length of the lower glume and about J^ the length of the 

 upper glume. 

 16A. Culms 30-80 cm. long; panicles nodding; lemmas 4-5 mm., rarely 3.5 mm. long; anthers 1.5-2.2 mm. long. 



14. P. sachalinensis 

 16B. Culms usually less than 30 cm. long, stouter; panicles erect or nearly so; lemmas 5-6 mm. long; anthers 1.6-2 mm. 



long 15. P. l{pmarovii var. shinanoana 



14B. Spikelets green; lemmas usually 2-3.5 mm. long, sometimes variegated with purple. 

 17A. Ligules 3-6 mm. long, if less than 3 mm. long, acute at tip. 



18A. Lemmas with prominent intermediate nerves, the marginal nerves glabrous or short-pubescent near base; panicles 



ovate, with spreading branches; anthers 1-1.5 mm. long 16. P. trivialis 



18B. Lemmas with weak or obsolete intermediate nerves, the marginal nerves short-pubescent at base. 



19A. Culms smooth; ligules usually obtuse; panicles broad, efluse; lemmas with obsolete intermediate nerves. 



17. P. palustris 

 19B. Culms scabrous below the panicles and on upper half of the internodes; ligules acute; panicles usually narrow 



and contracted; lemmas with weak but distinct intermediate nerves 18. P. sphondylodes 



17B. Ligules 0.5-1.5 (-2) mm. long, obtuse to truncate. 

 20A. Culms densely tufted, erect, the basal sheaths sometimes tinged red-purple; plants estoloniferous. 



21A. Ligules 1-2 mm. long; uppermost culm-leaves shorter than the sheath 19. P. viridula 



21B. Ligules scarcely developed; uppermost culm-leaves mostly longer than the sheath 20. P. nemoralis 



20B. Culms solitary or loosely tufted; plant stoloniferous; anthers 1.2-1.5 mm. long. 



22A. Sheaths slightly compressed; panicles open, loose; spikelets prominently compressed, pale or yellowish green. 



21. P. matsumurae 

 22B. Sheaths scarcely compressed; panicles dense and contracted; spikelets moderately compressed, green. 



22. P. pratensis 



lOB. Culms strongly compressed, 2-edged, erect from long creeping base; anthers 0.8-1.2 mm. long, about half as long as the 



lemma; panicles green, dense; lemmas 1.5-2.5 mm. long 23. P. compressa 



1. Poa annua L. Stjzume-no-katabira. Soft annual, leaf-blades flat, flaccid, 10-15 cm. long, 1.5-3 mm. wide, nearly 

 10-30 cm. high, tufted, glabrous; leaf-blades smooth, flat, 4-10 smooth; sheaths slightly compressed, nearly smooth; ligules 

 cm. long, 1.5-3 mm. wide; ligules semirounded, 3-6 mm. hyaline; panicles 10-20 cm. long, narrowly ovate, nodding, 

 long; panicles broadly ovate, usually 4-5 cm. long, the green, the branches geminate, scabrous, slender, spreading; 

 branches geminate, rather thick, smooth, spreading; spikelets spikelets ovate, compressed, 3- to 5-flowered, 3-5 mm. long; 

 ovate, pale green, 3-5 mm. long, 3- to 5-flowered; glumes 1- to glumes lanceolate, acute, unequal, 1- to 3-nerved, with scabrous 

 3-nerved, nearly smooth, the lower 1.5 mm. long, the upper keel, the lower 1.5 mm., the upper 2.5 mm. long; lemmas nar- 

 narrowly ovate, 2-2.5 mm. long, acute; lemmas about 3 mm. rowly ovate, about 2.5 mm. long, appressed-pubescent on the 



long, sometimes white-pubescent on lower half, the nerves sides below and on the nerves, obtuse. ^May-July. Shaded 



white-pubescent except near the tip, the intermediate nerves places in lowlands and low mountains; Hokkaido, Honshu, 



often glabrous, the web wanting or nearly so. ^Mar.-Nov. Shikoku, Kyushu; very common. Formosa, Korea, and 



Cultivated fields and along roadsides; Hokkaido, Honshu, Shi- China. 



koku, Kyushu; very common. A cosmopolitan weed. Var. submoniliformis Makino. Tama-mizo-ichigo-tsunagi. 



Var. reptans Hausskn. P. supina sensu auct. Japon., non A few basal internodes of culms bulbously thickened. Oc- 



Schrad. Tsuru-suzume-no-hie. With elongate creeping curs less frequently with the typical phase. 



innovation-shoots, bearing new ones from the nodes. Rare 4. Poa hisauchii Honda. P. acroleuca var. spicijormis 



in our area. Europe. Honda Yama-mizo-ichigo-tsunagi. Closely allied to the 



2. Poa crassinervis Honda. Tsukushi-suzume-no-ka- preceding; leaves vivid green; panicles narrow with rather 

 tabira. Closely allied to the preceding; ligules 2-3 mm. erect branches, lanceolate, nodding; lemmas broadly lanceolate, 

 long; panicles oblong, the branches in pairs, rather thick; about 3 mm. long, vivid or yellowish green, glabrous, rather 

 spikelets oblong, 4-6 mm. long, 3- to 6-flowered, pale green; acute, the intermediate nerves slender but distinct, glabrous, 

 glumes narrowly oblong, the upper 3-nerved, 3 mm. long, the the midrib and marginal nerves pubescent on lower half, the 



lower 2 mm. long; lemmas narrowly oblong, obmse, with web distinct; anthers short. ^May-July. Shaded places in 



glabrous sides, the intermediate nerves strong, white-villous mountains; Hokkaido, Honshu, Shikoku, Kyushu; common, 



below the middle, the web obscure. Apr.-June. Honshu ^Korea. 



(IzumoProv.), Shikoku, Kyushu; rare. 5. Poa nipponica Koidz. 0-ichigo-tsunagi. Allied 



3. Poa acroleuca Steud. P. psilocauUs Steud.; P. jami- to No. 1, but more robust and taller; culms 40-50 cm. long; 



Harts Steud.; P. acroleuca var. psilocauUs (Steud.) Munro leaf -blades flat, thin, 10-20 cm. long, 3-7 mm. wide; ligules 



Mizo-icHiGo-TsuNAGi. Green, soft, glabrous annual or short- 1-2 mm. long; panicles open, ovate, 10-20 cm. long, branches 



lived perennial; culms smooth, slender, 30-80 cm. long, weak; scabrous; spikelets vivid green, broadly ovate, 4-5 mm. long; 



