106 ENGLISH BOTAXY. 



each with a clubshaped vitta, attenuated towards the top, and not 

 reaching the base. Involucre and involucels few-leaved. 



A biennial herb, with pinnate leaves and paniculately branched 

 stems, with irregular few-flowered umbels of greenish-white flowers. 



The name of this genus of plants is said to be derived from the Celtic word rizon, 

 a brook, some of the species being inhabitants of running streams. It is the oiouv of 

 Dioscorides. 



SPECIES I— SI SON A MO MUM. Linn. 



Plate DLXXVIII. 



Reich. Ic. Fl. Germ, et Kelv. Vol. XXI. Tab. 1849. 

 Billot, Fl. Gall, et Germ. Exsicc No. 773. 



Stem erect, paniculately branched. Leaves pinnate, the lower 

 ones with the leaflets oblong-lanceolate, slightly lobed and mucro- 

 nate-serrate ; upper leaves with the leaflets deeply-cleft into linear 

 or strapshaped divaricate segments. 



In hedge-banks, waysides, and waste places. Frequent in the 

 South of England, becoming more rare towards the North. Reported 

 from Berwickshire, on insufficient authority. 



England, Scotland ? Biennial. Late Summer 

 and Autumn. 



Rootstock tapering, producing a tuft of spreading shortly-stalked 

 leaves, with 3 or 4 pairs of pinnae ; pinnae sessile or subsessile, 

 abrupt or subcordate at the base, cut, finely serrated, the serratures 

 with curved margins, and terminating in mucronate points. Flower- 

 ing-stem 1 to 3 feet high, with leaves similar to the root-leaves, but 

 with the pinnae longer and narrower (1 to 2 inches long) ; uppermost 

 leaves sub-biternate, with short linear, sometimes almost filiform 

 segments. Branches short, divaricate, with terminal and axillary 

 stalked umbels. Umbels with the rays spreading, all unequal, the 

 longest f to 1| inch long ; umbellules of few flowers, pedicels all 

 unequal, the longest J to J inch long. Involucre of 2 to 4 short 

 linear subulate leaves; involucel of 2 to 4 lanceolate leaves, not 

 half the length of the longest rays of the umbellule, and applied 

 to them. Flowers -^ inch across, white. Petals sub-orbicular, 

 deeply notched, with an inflexed point. Anthers incurred. Cremo- 

 carp ovate-globular, dark chestnut-brown, with the ribs prominent 

 and a little paler. Styles about equal to the stylopod, reflexed. 

 Columella split to the base. Plant glabrous, rather light-green. 



Extremely like Petroselinum segetum in habit, but besides the 

 technical difference of the vittse thickened towards the bottom and 

 not reaching the base of the carpels, the leaves are paler green, 

 the leaflets generally broader, the upper ones with liner segments, 



