602 



FART III. THE CLASSIFICATION OF PLANTS. 



rical. Dicentra spectabilis is a favourite ornamental plant ; both the outer petals 

 are spurred, the two inner petals are hollowed at their apices, so that they 

 completely enclose the anthers. In Hypecoum the flower is isobilaterally sym- 

 metrical, but the petals are not spurred, and there are four stamens, two lateral 

 forming the outer whorl, and two antero-posterior forming the inner whorl : 

 fruit usually indehiscent. In Corydalis and Fumaria only one of the outer 



Fig. 405. — A Flower of Dicentra spectahilis -. one of the outer petals is removed: s pedicel; 

 ca the outer, ci the inner petals ; / stamens. B The three stamens of one side, seen from 

 within : /filaments ; a the middle complete anther ; a^ a, the lateral half-anthers. C Flower- 

 bud, with the sepals, which soon fall off, still adhering (fc)'; (nat. size). Diagram of Fumi- 

 tory. 



petals is spurred, and consequently the flower is irregular and laterally zygo- 

 morphic. In Corydalis the fruit is a two-valved capsule with numerous parietal 

 seeds : some species, e.g. C. cava and solida, have a tuberous rootstock ; others, 

 as C. lutea and aurea, have rhizomes. Fumaria officinalis and others (Fumi- 

 tories) are common in fields ; the ovaries contain but few ovules, and of these 

 only one ripens to a seed ; fruit globose, indehiscent. 



Order 3. Cruciferj;. Flowers regular, isobilateral : floral for- 

 mula K'2 + 2, (7x4,^2 + 2-, &^l The four petals form a whorl, 

 alternating with the four sepals as if the latter formed one whorl ; 

 ^ there are, however, three perianth- whorls, as 



in the two preceding families ; but whereas 

 in them only the outermost whorl is sepa- 

 loid, in this family the two outer whorls 

 are sepaloid, and the innermost, which alone 

 is petaloid, is a whorl consisting of four 

 instead of two members. The two outer 

 Fig. 406.— Diagram of the stamens are lateral, as in those families ; the 

 flower of Cruciferfe. ^^^ inner ones, which in most Fumariacea) 



are apparently divided, are here duplicate, having longer filaments 

 (Fig. 407 B h h) than the outer ones (a) ; hence the flower is tetra- 

 dynamous. There are usually four, sometimes more, glands at the 



