COMPOSITE 145 



Cotyledons ovate-oblong, obtuse, very slightly eruarginate, fleshy, 

 somewhat incurved, light green above, tinged with red below, 

 glabrous, one-nerved, with short petioles. 



Stem short, erect, herbaceous ; primary internodes very slightly 

 developed. 



First leaves simple, deeply pinnatifid, petiolate ; segments oppo- 

 site, sessile, linear, acute, glabrous, light green, one-nerved. 



Calendula officinalis, L. 



Achene polymorphic those of the ray incurved, in two to 

 three series, varying greatly in length and outline, muricate on the 

 back, pubescent, the outermost ones often narrow and greatly elon- 

 gated or drawn out into a beak, and more or less produced into a 

 hooklike appendage at the base. The next set within this is similar 

 but furnished with broad wings, which are involute at the margin 

 and more or less pubescent as well as muricate ; the inner ones are 

 strongly incurved, often forming a complete ring, narrowly winged 

 with the wings involute at the margin, or wingless, short, muricate 

 at the back, smooth on the ventral face, with the hooklike appendage 

 still present at the base. 



Seed terete or oblanceolate, and tapering to the base, more or 

 less compressed dorso-ventrally, and conforming to the outline of 

 the achene, glabrous ; testa thin, pale, membranous ; hilum and 

 micropyle inferior, contiguous ; chalaza apical, superior. 



Endosperm absent. 



Embryo large and filling the entire seed, colourless, more or less 

 curved in conformity with the achene and seed ; cotyledons spathu- 

 late, obtuse, entire, or the outer dorsal one sometimes minutely 

 emarginate, tapering into the radicle and lying in the broader dia- 

 meter of the seed with their backs to the axis or centre of the disc, 

 plano-convex, subfleshy ; radicle tapering to an obtuse point, lying 

 in the narrow basal part of the seed, about half the length of the 

 cotyledons or less. 



Germination. 



A. The outermost achenes of the capitulum. 



The radicle pushes out at the base of the fruit, and the energy 

 of the swelling cotyledons is sufficient to split the achene into two 

 or three valves longitudinally, that is, dorso-ventrally, or along 

 the back and along the front on either side of the basal hook-like 

 process. The hypocotyl has then no difficulty in extricating the 

 cotyledons. If moderately covered with soil during germination, 

 the seed is so loaded owing to the extent of its superficial area, that 



II, L 



