CRUCIFER^E 175 



ing a tendency to become emarginate, tapering to a petiole-like base, 

 with a few alternate, ascending slender nerves, the uppermost strong 

 pair of which incurve and unite with the midrib below the apex, 

 finely reticulate, and all the veins seen only by transmitted light, 

 glabrous, light green above, paler beneath, petioles flattened above, 

 convex beneath, slightly connate at the base ; average length of 

 three long cotyledons 4*2 cm., of three short ones 3*33 cm. 



Stem herbaceous, developed when about to flower ; primary 

 internodes undeveloped. 



Leaves simple, radical and cauline, alternate, petiolate, hairy on 

 both surfaces, alternately and ascendingly incurvinerved ; nerves 

 uniting at the apex, obscurely reticulate ; petiole tapering upwards 

 from a rather broad, clasping base, channelled on the upper side, or 

 finally becoming more or less flattened. 



Nos. 1 and 2. Spathulate-obovate, or oblong, or oval, obtuse, 

 entire, or with inconspicuous glandular teeth. 



No. 8. Similar. 



No. 4. Oblong, obtuse, entire, with glandular teeth. 



Zilla myagroides, Forsk. 



Fruit a nut-like silicula, ovoid or subglobose, slightly compressed 

 laterally, shallowly ridged and furrowed longitudinally, tipped with 

 the subulate or conical, persistent style, two-celled, two-seeded, inde- 

 hiscent, glabrous, pale ashy grey, or more or less blackened ; sub- 

 stance of pericarp differentiated into an outer, thick, pale-coloured, 

 corky layer, and an inner, thick, hard and almost bony layer fur- 

 nished with wings extending through the cortex to the circum- 

 ference of the fruit. 



Seed obovoid, conforming to the cavity of the loculus, somewhat 

 compressed, but convex dorsally ; much compressed and almost 

 flattened ventrally, pale brown, smooth, almost shining, very unequal 

 at the upper and basal end where it runs out at one side into an 

 obtuse point ; testa comparatively thin, coriaceo-membranous ; hilum 

 in the sinus formed by the curvature of the seed, that is between 

 the radicle and the part containing the cotyledons ; rnicropyle at 

 the upper and most elongated point of the seed ; chalaza lateral, 

 forming a dark brown spot near the hilum, but on the opposite side 

 of the latter from the micropyle. 



Endosperm absent. 



Embryo large and filling the seed, doubled upon itself. 



Cotyledons rotund-cuneate, emarginate, conduplicate, and incum- 

 bent, probably about equal in size, as the inner one projects some 

 way from beneath the outer, pale yellow ; radicle cylindrical, sub- 



