506 



NATURAL HISTORY OF PLANTS. 



Parieiaria officinalis. 



elliptical or ovate -oblong. Wall Pellitory is a perennial herb covered 

 with hooked hairs, possessing alternate entire tricostate leaves, 



sprinkled with punctate cysto- 

 liths, petiolate, with very small 

 stipules or none. The axillary 

 flowers are usually grouped five 

 together into a little cyme on 

 either side of a little axillary 

 twig. The central flower is 

 female; the four others, male or 

 hermaphrodite, are paired on either 

 side, axillary to a bract, accom- 

 panied by two lateral bractlets, forming with it a sort of involucre. 

 Other species are distinguished by their frutescent or annual 

 stems, their unsymmetrical cymes, uniparous by abortion, their 

 leaves three-ribbed at the base. In P. arborea x made into the 

 distinct genus Gesnouinia 2 the stigma is linear, not aspergilliform, 

 and the cymes are trifloral, with the central flower female : from 

 these characters we make it a separate section. So we regard 

 P. Soleirolii? a species from Corsica and Sardinia, which has been 

 made into the genus Helxine ; 4 its inflorescence is reduced yet more, 

 containing only one flower, male or female, in the axillary involucre. 

 Thus constituted, Parieiaria comprises a dozen species' from the 

 cold and temperate regions of both Worlds. Next to it come two 

 closely allied genera, HemistyJis and Roussclia, representing the same 

 t}^pe, very slightly modified in America. 



V. FORSKOHLEA SERIES. 



ForskoMea* (figs. 547-551) has monoecious flowers, reduced to a 



1 Lh£e., in Roz. Journ., xxxiii. 55. 



2 Gaudich., Toy. Uran., Pot., 502. — Wedd., 

 Monogr., 521, t. 18, B ; Prodr., 235 49 . 



3 Spbeng., Syst., iv. p. ii. 218.— Geen. & 

 Gode., Fl. de Fr., iii. 110.— P. repens Soleib. 

 (ex Mut., Fl. Fr., iii. 172). 



4 Req., in Ann. Sc. Nat., ser. 1, v. 384. — 

 Wedd., Monogr., 529, 1. 18, A ; Prodr., 235 *>.— 

 Soleirola Gaudich., Voy. Uran., Pot., 504: 

 Voy. Pon., Pot., t. 114, B. 



5 L., Spec, 1492.— Foest., Prodr., n. 387.— 

 Del., Egypt., 137, t. 50.— Due., in Duchtr. 

 Rev. Pot., ii. 427.— Bl., Mtis. Lugd.-Pat., ii. 

 245.— Webb, Phyt. Canar., iii. 264. — Wedd., iu 

 Ann. Sc. Nat., ser. 4, i. 207 {Gesnouinia). — 

 Dub., Pot. Gall., i. 418 (Helxine).— Viy., App. 

 Fl. Cors. Prodr., 7 (Parieiaria). — Ledeb., Fl. 

 Poss., iii. 639. 



6 Mantiss., 11, n. 1262.— Ekdl., Gen., n. 



