386. Moraceae; Urticaceae 



gin; achenes ovate-orbicular, inflated-lenticular, yellow-brown, lobe larger than the lateral ones; pistillate spikes pendulous, 



puberulous near the top, glandless, 4-5 mm. long and as wide, short-pedunculate, pale yellow-green, ovoid-globose in fruit, 



Sept.-Oct. Thickets and roadsides in lowlands; Hok- the bracts obtuse, 15-20 mm. long and as wide, concave, 



kaido, Honshu, Shikoku, Kyushu; very common. Ryukyus, papery-membranous, accrescent, ovate; achenes inflated- 

 Formosa, and China. lenticular, 2.5-3 mm. long and as wide, covered with minute 

 2. Humulus lupulus L. var. cordifolius (Miq.) Maxim, impressed points and yellow discoid glands; staminate in- 

 H. cordifolius Miq. Kara-hana-s6. Much-branched, scan- florescence paniculate, erect, 10-15 cm. long, the flowers short- 

 dent, perennial herb, retrorsely prickly on stems and petioles; pedicelled. Aug.-Sept. Thickets in mountains; Hokkaido, 



leaves green, long-petiolate, ovate-orbicular, 5-12 cm. long Honshu (centr. and n. distr.). China. The typical phase 



and as wide, acuminate, cordate at base, scabrous on both sur- occurs in Europe, 

 faces, rather irregularly toothed, often 3-lobed, the terminal 



Fam. 69. URTICACEAE Ira-kusa Ka Nettle Family 



Monoecious or dioecious herbs, rarely trees, often with stinging hairs; leaves opposite (often unequally so) or alternate, simple, 

 toothed or incised, petiolate, commonly with cystoliths in the epidermal cells, the stipules free or connate, often caducous; flowers 

 in glomerate cymes, the perianth 2- to 5-cleft, sometimes utriclehke; stamens as many as the perianth-segments and opposite 

 them, the filaments incurved in bud; ovary superior, 1-locular; style simple or nearly absent, the stigma capitate, penicillate or 



pinnate, sometimes filiform; ovules solitary, usually orthotropous; fruit an achene, the endosperm oily. About 40 genera, 



with about 500 species, cosmopolitan. 



lA. Stinging hairs present. 



2A. Leaves opposite; stigma penicillate-capitate 1. Vrtica 



2B. Leaves alternate; stigma filiform 2. Laportea 



IB. Stinging hairs absent 

 3A. Pistillate perianth not utriclelike in fruit, usually shorter than the achene or deeply lobed to parted. 



4A. Leaves opposite 3. Pilea 



4B. Leaves alternate. 



5A. Leaves equilateral, petiolate 4. Nanocnide 



5B. Leaves not equilateral, sessile or short-petiolate. 



6A. Pistillate perianth suppressed, not accrescent; bracts of the pistillate inflorescence connate, forming a disclike receptacle at 



base 5. Elatostema 



6B. Pistillate perianth 4- to 5-parted, covering part of the achene; bracts of pistillate inflorescence not connate 6. Pellionia 



3B. Pistillate perianth connate and wholly investing the achene in fruit. 

 7A. Leaves toothed; herbs or shrubs. 



8A. Pistillate perianth membranous, not adnate to the achene; suffrutescent herbs with alternate or opposite leaves. . . 7. Boehmeria 

 8B. Pistillate perianth adnate to the achene, fleshy or juicy in fruit; woody plants with alternate leaves. 



9A. Pistillate perianth fleshy in fruit; stigma discoid or peltate 8. Villebrunea 



9B. Pistillate perianth juicy in fruit; stigma capitate 9. Debregeasia 



7B. Leaves entire; herbs or essentially so (in ours). 



lOA. Glomerules involucrate at base; stigma short-linear, penicillate; delicate herbs 10. Parietaria 



lOB. Glomerules without involucral bracts; stigma filiform, pilose, suffrutescent herbs. 



11 A. Lateral nerves of leaves much shorter than the midrib; perianth-segments of the staminate flowers without a transverse 



fold or gibbosity on back 11. Pouzohia 



IIB. Lateral nerves reaching nearly to the apex of leaves; perianth-segments of staminate flowers with a transverse fold or gib- 

 bosity on back 12. Gonoslegia 



1. URTICA L. Ira-kusa Zoku 



Dioecious or monoecious annuals or perennials with stinging hairs; leaves opposite, petiolate, dentate or serrate, 3- to 5-(7-) 

 nerved, the stipules free or connate between the petioles; flowers in glomerate cymes, the staminate 4-merous; pistillate perianth 

 4-merous, the segments small, unequal; ovary erect; stigma penicillate-capitate; ovules orthotropous; achenes ovate or oblong, 

 more or less flattened, enclosed by 2 accrescent inner perianth-segments. About 40 species, in the temperate and warmer re- 

 gions of the N. Hemisphere. 



lA. Stipules 4, connate, in a pair. 



2A. Leaves broadly ovate or cordate-orbicular, with 7-11 coarse, narrowly deltoid, often double teeth on each side, the petioles slightly 



shorter than the leaves \. U. thunbergiana 



2B. Leaves narrowly to broadly ovate, rounded to shallowly cordate at base, with 10-25 usually simple teeth on each side; petioles much 



shorter than the leaves Z. V. plaiyphylla 



IB. Stipules 4, free, lanceolate or broadly linear. 



3 A. Leaves narrowly ovate-oblong to lanceolate, 6-12 cm. long 4. U. angustifolia 



3B. Leaves ovate to broadly so, 5-10 cm. long 2. U. laetevirens 



1. Urtica thunbergiana Sieb. & Zucc. Ira-kusa. Per- orbicular, 5-12 cm. long, 4-10 cm. wide, acuminate, cordate 

 ennial; stems erect, simple or slightly branched, 40-80 cm. at base, coarsely incised-serrate, with scattered coarse ap- 

 long, retrorsely puberulous; leaves broadly ovate to ovate- pressed hairs above, puberulent beneath especially on nerves, 



