380 



VARIOUS PLANT (i ROUPS 



Fig. 299, I. — Flower of Oxeye 

 (Heliopsis scahra, Sunflower 

 Family, Compositce). A-N, 

 stages in the development of 

 a tubular floret, enlarged. .4, 

 very young stage in whirh 

 tlie flower (fl) is as yet with- 

 out petals but is plainly dis- 

 tinguishable from its bract 

 (6). B, shows the ringlilie 

 swelling {/c) which represents 

 the calyx, and five knoljs (c) 

 which are the beginnings of 

 petals. C, a somewhat more 

 advanced stage, just before 

 the appearance of stamens. 

 D, showing the stamens (a) 

 just appearing. E, ^ same 

 stage as D, cut vertically. 

 F, later stage in which the 

 beginnings of two carpels (e) 

 appear. G, same stage, 

 viewed from the side, show- 

 ing that the petals or corolla 

 lobes have curved inward 

 protectively and are united 

 below by a ring of tissue 

 wlfjch by upward growth be- 

 comes the corolla-tube bear- 

 ing the five lobes above. H, 

 same stage, cut vertically; 

 showing the upward growth 

 of the carpels (g) leaving a 

 hollow in the stem-tip (torus). 

 J, later stage, cut verticall>- 

 through the middle of the 

 carpels (g) showing a deepen- 

 ing of the hollow in the torus. 

 K, bud of mil Idle age, show- 

 •■ ing the corolla-tube (c) with 

 its five lobes well developed, 

 and lower part of the pistil 

 ((7), enveloped by the torus, 

 becoming plainly distinct as 

 an "inferior ovary." L, a 

 somewhat later stage, cut ver- 

 tically, showing the appear- 

 ance of two styles (s) , still dis- 

 tinct, and a young ovule (a) 

 with its outer coat half-grown. Al , bud almost ready to open; the two 

 styles having grown into one {s); the anthers {a) joined into a tube; 

 the sepals (k) distinct prominences on the top of the torus, a nectar- 

 gland (ri) ; and the ovule (o) completely formed. A^, Tubular floret, 

 open, showing anther-tube (a), corolla-tube (c), and inferior ovary (g). 

 OS, stages in the growth of a ray-floret. 0, ver>' earl^- stage in which 

 five petal-lobes appear, three of which, however, are distinctly larger 

 than the other t\\-o. /-•, later stage in "which the three larger lobes (c) 

 have become much lai'ger, while the two smaller ones have remained 

 inide\-el()t,e(l. (J, ra\--fl( iri-t about half-grown, showing two of the 

 fhrer ]M'l;il-Ktbi-s seiiaratc to the base. R, same, cut vertically betw^een 

 the two ,se]iarate petals, showing the union of the middle one (at the 



