372 siUM. f^'^" "• °^''^-^ "• 



Habitat. — Ditches and rivulets ; frequent in England and Ireland ; 

 but not common in Scotland. 



Perennial ; flowering in July and August. 



GENUS LXI. SlUM.— Linn. Water Parsnip. 



Gen. Char. Ca///.r margin of five teeth. Pf'/w/s obcordale, with an 



intlexed point. Fniit laterally compressed or contracted. Disk 



flatlish, with a depressed margin. Sti/Ies reflexed. Carpels with 



five equal obtuse filiform ridges, the lateral ones forming the 



margins, Chayinels with three superficial vittce. Albumen 



rounded at the back, flat in front. General involucre mostly 



of several linear segments, partial of numerous ones. — Name from 



o-iitii, to move; from the plant being almost constantly agitated 



by the water: or, according to Theis, from the Celtic word sitv, 



water. 



1. .S. lati'folium, Linn. (Fig. 434.) broad-leaved Water Parsnip. 



Stem erect ; leaves pinnated ; leaflets lanceolate, equally and acutely 



serrated ; umbels terminal ; involucre of numerous linear segments. 



English Botany, t. 204. — English Flora, vol. ii. p. 56. — Ilooker, 

 British Flora, vol. i. p. 130. — Lindley, Synopsis, p. 121. 



Root of slender long branched fibres, from the creeping underground 

 stem. Flowering steyns erect, angular, smooth, deeply furrowed, from 

 two to six feet high, smooth, hollow, branched, and leafy. Leaves 

 alternate, pinnate, on long striated footstalks, with a dilated base, with 

 membranous edges sheathing the stem, the lower ones or those under 

 the water sometimes bi-pinnate, with the margin of the leaflets irre- 

 gularly cut and serrated, the upper ones with about five pairs, and an 

 odd one of lanceolate smooth leajlets, of a lively green above ; beneath 

 paler, somewhat glaucous, with a mid-rib and numerous fine netted 

 veins, the margin fine, and acutely serrated, fwie/s teiminal, large, 

 of numerous long angular ray.?, of nearly equal lengths, partial of 

 numerous short slender nearly equal ones. General involucre mostly 

 of several linear reflexed segments, sometimes one or two of them 

 pinnated, partial of several lanceolate mostly unequal ones. Flourrs 

 white, crowded. Calyx of five teeth, sometimes very small. Petals 

 inversely heart-shaped, or obcordate, with an inflexed small point. 

 Stamens with slender filaments, and rather large inversely heart- 

 shaped anthers, of a purplish colour. iSti/les short, reflexed, or 

 spreading. Stigmas small, obtuse. Disk flattish, with a depressed 

 margin, fleshy, yellowish, crowning the ovate /ruj/, with thcsides much 

 compressed or contracted, smooth. Carpels with five filiform obtuse 

 pali.^h equal ridi/es, the lateral ones forming the margins. Channels 



