466 Identification and Eradication of Weeds, [sept., 



and is, perhaps, in some districts, the more common weed. 

 When present in quantity,*as is often the case, Runch is quite 

 as harmful as common charlock, and it occurs on soils similar 

 to those specified for that weed. 



Seeds. — The seeds of wild radish are often enclosed in an 

 egg-shaped or cylindrical portion of the pod. They are 

 variable in size and shape, but may be described as oval or " 

 egg-shaped, somewhat compressed, reddish-brown to dark- 

 brown, apparently smooth, but seen under a lens to be covered 

 with a fine whitish network due to shallow depressions, and 

 ■J- in. (3 mm.) in length (Fig. 2, a). Schultz says they contain 

 30 to 35 per cent, of oil. 



Seedlings. — In the early stage seedling (Fig. 2, b) the root 

 is short and fibrous, and the hypocotyl thick and fleshy, 

 whitish, and smooth. The cotyledons are broadly heart- 

 shaped, about equal, with equal lobes, smooth, light green 

 above to yellowish-green or nearly yellow beneath, with alter- 

 nately branched midrib, and long, rather broad petiole, which 

 is channelled above and convex below. They are about J- in. 

 long by J in. broad (8 mm. by 12 mm.). The petioles are 

 unequal in length. 



In the second stage (Fig. 2, c) the cotyledons are larger, 

 more clearly heart-shaped, and the alternate branches of the 

 midrib more clearly defined. They are now about f in. long 

 by f in. broad (1 cm. by 1*5 cm.). The first leaves are irregular 

 or nearly spatulate, lobed and toothed, pointed at the apex, 

 dark green and very hairy, with many veins which give a 

 wrinkled appearance to the surface, and are borne on stalks 

 about half the length of the blade. 



The third stage is practically an enlarged form of the second, 

 but the cotyledons have grown considerably, to f in. long 

 by 1 in. broad (2 cm. by 2*5 cm.), and with petioles £ in. 

 and 1 in. long respectively (2 cm. and 2*5 cm.). The now 

 elongate-oval leaves are deeply lobed towards the base, the 

 lobes, however, being small. The whole plant is dark green 

 and very rough with hairs, and before the flowering stem is 

 sent up (e.g., if the plant is a biennial) the leaves lie close to 

 the ground, and are in rosette form (Fig. 2, d). 



Mature Plant. — Runch is a stout, erect, spreading, and 

 branched annual (or biennial), attaining 1-3 ft. in height. It 

 is covered with rough hairs ; the lower leaves are divided or 



