388 



Urticaceae 



lA. Leaves orbicular, less than 10 mm. long, very obtuse, undulately toothed or nearly entire, with brown spots beneath, the cystoliths more 



or less transversely arranged above; achenes smooth 1- ^ • peploides 



IB. Leaves longer than broad, 1.5-13 cm. long, acute to caudate at apex, distinctly toothed, without spots beneath, the cystoliths rather ir- 

 regularly arranged above. 

 2A. Pistillate perianth unequally 3-lobed. 



3A. Pistillate perianth divided nearly to base, the longer segments lanceolate or linear-lanceolate, obtuse; achenes more or less red- 

 brown spotted; leaves broadly rhombic-ovate, 1.5-10 cm. long. 

 4A. Pistillate perianth-segments shorter than the achene, linear-lanceolate; achenes about 1.2 mm. long; leaves 3-10 cm. long. 



2. P. mongolica 

 4B. Pistillate perianth-segments, or at least one of them, as long as to slightly longer than the achenes; achenes 1.8-2 mm. long; 



leaves 1.5-5 cm. long, acute with an obtuse tip 3. P. hamaoi 



3B. Pistillate perianth spathelike, with 3 acute-deltoid teeth or with as many ovate lobes at apex; achenes smooth or verrucose; leaves 

 oblong to ovate, 6-15 cm. long. 



5A. Leaves oblong, acuminate; achenes 1.3-1.5 mm. long, smooth 4. P. petiolaris 



5B. Leaves oblong-ovate, broadest slightly below the middle, long caudate-acuminate; achenes about 0.6 mm. long, strongly ver- 

 rucose 5. P. psetidopetiolaris 



2B. Pistillate perianth with 5 nearly equal segments, parted to the base; achenes smooth, not brown-spotted. 



6A. Peduncles of pistillate inflorescence mammillate-puberulous on one side; leaves 2-12 cm. long, narrowly ovate or oblong, with 



7-13 coarse teeth on each side 6- f ■ k'otensis 



6B. Peduncles of pistillate inflorescence glabrous; leaves 1-3 (-8) cm. long, broadly ovate or ovate-orbicular, with 3-6 coarse teeth on 

 each side 7. P. japonica 



1. Pilea peploides (Gaudich.) Hook. & Am. Dubreulia 



peploides Gaudich. Koke-mizu. Glabrous somewhat 



tufted monoecious annual, 7-15 cm. high, the stems branching 

 below; leaves orbicular or depressed-ovate, 6-10 mm. long and 

 as wide, very obtuse to rounded at the tip, usually sparingly 

 undulate-toothed, broadly cuneate and 3-nerved at base, the 

 cystoliths linear, more or less transversely arranged on the 

 upper surface, brown-spotted beneath, the petiole shorter or 

 longer than the blade; flowers more or less capitate in leaf- 

 axils, sessile, the perianth-segments broadly oblanceolate, 

 shorter than the achenes; achenes smooth, pale brown, broadly 



lenticular-ovate, about 0.6 mm. long. Mar.-Aug. Honshu 



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



Formosa, China, Korea, Manchuria, Hawaii, Galapagos Isl., 

 Malaysia, and India. 



2. Pilea mongolica Wedd. P. viridissima Makino 



Ao-Mizu. Glabrous, soft, fleshy, monoecious annual; stems 

 erect, terete, often branched, 30-50 cm. long, pale green; leaves 

 deep green, broadly rhombic-ovate, 1.5-10 cm. long, 1-7 cm. 

 wide, short-acuminate or subacute with an obtuse tip, broadly 

 cuneate at base, coarsely deltoid-toothed, 3-nerved, glabrous or 

 scattered pubescent above and on margin, the petioles un- 

 equally paired, 1.5-10 cm. long; inflorescence densely cymose, 

 1-3 cm. long, the pistillate perianth-segments unequal, the 

 longer ones linear-lanceolate, obtuse, with a prominent slightly 

 raised midrib, Vi-V^ as long as the achene; achenes broadly 

 ovate-lenticular, 1-1.2 mm. long, with scattered slightly raised 



brown spots. July-Oct. Shaded places in lowlands and 



mountains; Hokkaido, Honshu, Shikoku, Kyushu. Korea, 



China, and e. Siberia. 



3. PUea hamaoi Makino. Mizu. Glabrous, soft, juicy 

 monoecious annual; stems erect, sparingly branched, green or 

 purplish, 20-40 cm. long; leaves deep green, broadly rhombic 

 to rhomboid-ovate, 1.5-5 cm. long, 1-3.5 cm. wide, acute with 

 an obtuse tip, broadly cuneate at the 3-nerved base, glabrous, 

 ciliate, sparingly toothed; cystoliths short; inflorescence cy- 

 mose, 5-20 mm. long, axillary; pistillate perianth-segments 

 unequal, the larger ones lanceolate or linear-oblong, as long as 

 to slightiy longer than the achene, very obtuse, with a promi- 

 nent midrib; achenes broadly ovate-lenticular, pale brown- 

 spotted, 1.8-2 mm. long. July-Oct. Shaded places; Hok- 

 kaido, Shikoku, Kyushu. China. 



4. Pilea petiolaris (Sieb. & Zucc.) Bl. Urtica petiolaris 



Sieb. & Zucc; P. strangulata Fr. & Sav. Miyama-mizu. 



Soft, juicy, monoecious perennial, 40-80 cm. high, glabrous, 

 sometimes sparingly branched below; leaves ovate to narrowly 

 so, or oblong, 6-15 cm. long, 3-5 cm. wide, acuminate with a 

 rather obtuse tip, obtuse or cuneate and 3-nerved at base, shal- 

 lowly toothed, the stipules rather large, deciduous; inflorescence 

 densely cymose, 1-4 cm. long, the pistillate perianth split to the 

 base on one side, broadly ovate, 3-toothed or -lobed, about half 

 as long as the achene; achenes broadly ovate, usually greenish 

 brown, lenticular, not spotted, 1.3-1.5 mm. long, broadly ovate. 



Aug.-Oct. Shaded wet places in mountains; Honshu 



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



5. Pilea pseudopetiolaris Hatus. Ko-miyama-mizu. 

 Slightly succulent perennial herb; rhizomes elongate, creeping; 

 stems erect, 40-80 cm. long; leaves narrowly ovate to ovate- 

 elliptic, 6-10 cm. long, 2.5-4 cm. wide, caudately long-acumi- 

 nate, rounded to obtuse at base, obtusely serrate, trinerved, 

 scattered pilose above, the petioles 2-3 cm. long; female cymes 

 axillary, solitary, about 1 cm. long, short-peduncled, densely 

 flowered; male cymes larger, 2-3.5 cm. long, nearly sessile, 

 glabrous; achenes ovate-fusiform, acute, about 0.6 mm. long, 

 densely verrucose. Aug.-Oct. Honshu, Shikoku, Kyushu. 



6. Pilea kiotensis Ohwi. Achudemia iseana Makino; 



P. iseana Makino Miyako-mizu. Glabrous perennial 



(?) herb; stems 30-40 cm. long, rather juicy and soft, some- 

 times slightly branched; leaves ovate to narrowly so, sometimes 

 oblong, 2-12 cm. long, 1-5 cm. wide, caudately acuminate with 

 an acute tip, cuneate at base, coarsely toothed, nearly glabrous 

 on both sides, 3-nerved, the stipules about 5 mm. long, decidu- 

 ous; pistillate inflorescence cymose, the peduncles short-puberu- 

 lous on one side or subsessile, the perianth-segments 5, elliptic 

 to oblong, nearly equal, obtuse, the midrib tuberculate on 

 back; achenes about 1 mm. long, 1.5-2 times longer than the 

 perianth, broadly ovate, lenticular, smooth, pale, not punctate. 

 Oct. Honshu (Kinki Distr.), Kyushu (n. distr.). 



7. Pilea japonica (Maxim.) Hand.-Mazz. Achudemia 

 japonica Maxim. Yama-mizu. Glabrous monoecious an- 

 nual; stems branched, 10-20 cm. long, slightly red-brown, 

 rather slender, soft, juicy; leaves broadly ovate or ovate-orbicu- 

 lar, 1-3 (-8) cm. long, obtuse or acute with an obtuse tip, 3- 

 nerved, the pairs unequal, ciliate, with 1-4 coarse teeth on 



