426 OX SEEDLINGS 



(usually about 3 mm.), flat or concave on the sides ; testa thin, 

 membranous, light brown or straw-coloured, smooth, not shining. 



2nd. Subrotund, slightly flattened laterally, 1-5-2-5 mm. in 

 diameter, biconvex; testa rather thick, crustaceous, bright black, 

 smooth and shining. 



Both kinds of seed are usually enclosed in the membranous, thin, 

 indehiscent utricle. 



In some sowings which I made, the brown seeds came up more 

 quickly than the black, as if the black were intended to remain for 

 awhile dormant. The subject, however, requires further study. 



Seedling. 



Primary root tapering downwards, flexuose, yellowish, with 

 short lateral rootlets, annual. 



Hypocotyl erect, terete, glabrous, short and merging indis- 

 tinguishably into the root. 



Cotyledons petiolate, falling away early,. linear, obtuse, about 

 1 cm. long including the petiole. 



Stem erect, terete, herbaceous, annual, pale green, glabrous, 

 shining, farinaceous in the upper and younger part ; 1st internode 

 1-5 mm. long ; 2nd 3 mm. ; 3rd 9 mm ; 4th 10-5 mm. 



Leaves simple, cauline, opposite, or the upper ones alternate, 

 petiolate, mealy when young, smooth and glabrous when mature, 

 pale green, or in the garden variety rubra of a deep reddish- 

 purple especially in the young state, trinerved at the base with a 

 branch from the lateral nerves into the basal lobes ; petioles sub- 

 terete, slightly flattened on the upper side and narrowly channelled, 

 glabrous. 



First pair oblong-ovate, obtuse, truncate, and sometimes with a 

 minute lateral tooth on each side at the base, very faintly trinerved. 



Second pair similar, but larger. 



Third pair in robust specimens triangular, obtuse, minutely and 

 obsoletely dentate or entire, truncate at the base. 



Fourth pair triangular, subacute, minutely denticulate, hastate, 

 truncate at the base. 



Fifth pair triangular, subacute, sagittate-hastate, more deeply 

 dentate on the lower half. 



Ultimate leaves large, triangular, sagittate-hastate, subcuspidate, 

 irregularly repand, serrate-dentate except towards the point, trinerved 

 with a strong branch from the lateral nerves entering the basal 

 lobes. 



Uppermost leaves near the inflorescence again becoming smaller 

 and less decidedly cut. 



