CUP FLOWERS 309 
gamosepalous and nearly regular. The carpel, which is 
somewhat fleshy when young, on ripening becomes dry 
and fibrous. This form of fruit is known as a “legume.” 
567. It should be noted that the flowers of the plum 
and the pea are very much alike in plan, the greatest 
difference being the irregularity of the corolla, and the 
fewer, united stamens. The pea represents an immense 
group of plants (Bean Family) of 6,000 to 7,000 species, 
which appear to have been developed from plum-like 
ancestors by their corollas becoming irregular. They 
constitute an evolutionary side line in which irregularity 
of the corolla (‘“‘zygomorphy”’) has been especially 
developed with reference to insect agency in pollination. 
568. The flower of the Garden Currant (Ribes) re- 
minds one a little of that of the Apple. Its cup is deep 
enough to enclose the ovary of the bicar- 
pellary pistil. The carpels are united at “VO 
their margins, so that there is but one 
cavity with two parietal placentae. The 
margin of the cup bears the perianth (five 
sepals, five petals) and the five stamens. The ovary 
in ripening thickens and softens its wall, becoming a 
many-seeded berry, a portion of which consists of the 
thickened cup. 
Fia. 186. 
Ribes. 
569. The cup of the Evening Primrose ~ 
(Oenothera) is very deep, not only en- 
closing the quadricarpellary ovary, but 
@ ) extending as a tube much beyond it. The 
earpels are wholly united so that the 
ovary has four many-seeded cavities. The 
Fig. 187. eight stamens (in two whorls) are borne 
' on the edge of the tubular cup, as are 
the four large yellow petals and the narrow, greenish 
sepals. The ripening ovary becomes hard and dry, 
