BAKER : PETASITES OFFICINALIS. 



35 



ON PETASITES OFFICmALIS. 



By H. G. Baker. 



I beg to forward you a description of Petasites officinalis as it occurs in 

 this neighbourliood, and should be glad if your readers would direct their 

 attention . to this plant as the form met with in this country seems to differ 

 from those found on the continent. Boreau describes two species in his 

 Flore du Centre de la France : I subjoin translations of his account of them, 

 and also a similar description of our own plant. 



P. riparia. Jordan ! Eoot-stock thick, fleshy, and spreading, producing 

 tufts of pubescent stems from eight inches to two feet in height furnished 

 with loose elongated reddish scales ; flower-heads, numerous, from one to 

 three on each peduncle, united in an oval oblong thyrsoid cluster which is nar- 

 rowed at the summit ; bracts lanceolate acuminate ; involucre oval, oblong, 

 not spreading out at the summit, with brown adpressed oblong obtuse 

 phyllaries which are shorter than the flowers and the pappus ; stigmas short 

 and oval ; leaves coming after the flowers and growing very large as the 

 season advances. They are furnished with long stalks, and in shape are 

 cordiform oval, unequally denticulate and slightly angular, green in colour, 

 and a little cottony on the upper side, whitish-tomentose beneath, with the 

 basal lobes not contiguous, the bottom of the space between them bordered 

 by a nerve, flowers reddish and scentless. 



P. pratensis. Jordan ! Eoot-stock thick and wide-spreading, producing 

 solitary pubescent stems, from eight inches to two feet in height, which are 

 furnished with numerous oblong or lanceolate reddish violet scales ; flower- 

 heads numerous, usually one or two, occasionally three on each peduncle, 

 united in an oval oblong thyrsoid cluster which is not narrowed to a point at 

 the summit and finally becomes exactly cylindrical ; bracts linear, lanceo- 

 late, acuminate, violet in colour; involucre oval, equal, with scales 

 of a beautiful violet colour, not adpressed, rather loose, oblong, a little 

 acute, surpassing the flowers and the pappus at the flowering time ; stigmas 

 short, linear, and erect, pappus equalling the flowers ; leaves coming after the 

 flowers, bright green, and cottony on the ujDper side, whitish subtomentose 

 beneath, somewhat undulated roundish cordiform, unequally denticulate, 

 slightly angular, the basal lobes rounded. The flowers are purplish and 

 slightly scented. 



