126 ENGLISH BOTANY. 



SPECIES I.-PARIETARIA DIFFUSA. Koch. 



Plate MCCLXXVIII. 



BcicTi. Ic. Fl. Germ, et Hclv. Vol. XII. Tab. DCLI. Fig. 1318. 

 P. officinalis, Sm. Engl. Bot. No. 879. 



Stems prostr.ate or ascending, rarely erect, commonly branched. 

 Leaves oval or elliptical, slightly acuminate, 3-nerved about the base. 

 Each half of the involucre 3- to 6 -cleft, containmg 1 to 3 flowers. 

 Perianth of the perfect flowers bellshaped-cylindrical, elongating after 

 flowering until it is nearly twice as long as the stamens. 



Var. a, genuina. 

 P. diffusa, Bah. olim. 



Stems decumbent, usually much branched. 



Var. ^^fallax. Gren. and Godr. 

 P. crccta, Bah. olim (non Koch.). 



Stems erect, usually nearly simple. 



On stony banks, rocks, and old walls and hedgebanks. Rather 

 common in England. Rather rare in Scotland, and absent from the 

 north of that country. Frequent and generally distributed in Ireland. 



England, Scotland, Ireland. Perennial. Summer, Autumn. 



Stems numerous, almost woody at the base, succulent at the apex, 

 purplish, streaked with green, usually much branched, but sometimes 

 nearly simple. Leaves 1 to 3 inches long, tapering gradually into the 

 short petioles, entire, without stipules. Involucre with 2 principal 

 lobes cut into several segments, containing a variable number of 

 flowers, the central flower female, placed between the 2 halves of 

 the involucre. Perianth of the lateral flowers elongating to about 

 \- inch and becoming reddish-brown, rarely pale brown, with green- 

 lipped segments. Seeds i^^ inch long, ovate-ovoid, compressed, black, 

 shining. Plant pubescent, the leaves dark green and somewhat 

 scabrous, with small raised points, hairy on both sides. 



The elongated tubular perianths of the fertile flowers distinguish 

 P. difi^usa from P. erecta, Koch^ which is a much stouter plant, with 

 nearly simple stems and more rhombic leaves. 



Pellitory of the Wall. 



Frcncla, Parictaire. German, Atisgchrcltetcs Glaskraut. 



GENUS 77.— U R T I C A. Toumef. 



Flowers monoecious or dioecious. Male flowers with the perianth 

 4- or 5-partite, the segments nearly equal: stamens as many as the 



