LEGUMINOS^. 



477 



presence of one or other of these characters the order may be recog- 

 nised. It is remarkable that one or other of these distinctions dis- 

 appears in a great number of cases. Csesalpiniese have irregular 

 flowers, with spreading petals and stamens adhering to the calyx; 



Fig. 702. 



Fig. 704. 



others have no petals at all, or some number less than five ; while 

 Mimosese have perfectly regular flowers and indefinite hypogynous 

 stamens. Detarium and other plants of this family bear fruits not 

 to be distinguished from a drupe. Leguminous plants and Roseworts 

 have so many features in common that it may be affirmed that no 

 positive character has been discovered to distinguish the one order 

 from the other, except the inferior position of the odd calycine lobe. 



Figs. 700-704. Organs of fnictification of Lathyms odoratus, Sweat-pea, a papilionaceous 

 flower, showing the structure of the natural order Leguminosae. Fig. 700. Diagram of the 

 flower, showing five divisions of the calyx, 5 petals, consisting of 2 parts forming the carina, 

 2 alse, and the vexillum, which is superior, 10 stamens in 2 rows, diadelphous ; ovary 1- 

 celled, formed by a single carpel ; one of the ovules shown with its funiculus attached to 

 the ventral suture. - Fig. 701. Longitudinal section of the flower of Lathyrus odoratus. 

 c c, Calyx, with five segments, e, Vexillum or standard, being the superior or posterior odd 

 petal, a. One of the alse, or wings, c a, One-half of the carina, or keel, t, Tube of the 

 stamens, the filaments being united in two bundles, or diadelphous. o, Ovary laid open, 

 showing the ovules attached to the placenta, on the ventral or upper suture, s. Stigma, at 

 the apex of the style, which is continuous with the ventral suture. Fig. 702. Fruit, a 

 Legume or Pod, openiiig by two valves, and dehiscing by the ventral and dorsal suture. 

 Seeds attached on each side of the ventral suture, curved upon themselves, having a 

 marked hilum and funiculus (podosperm or umbilical cord). Fig. 703. A Seed separated. 

 /, Funiculus, c, Hilum, which is imited to the funiculus, m, Micropyle or foramen. Fig. 

 704. Embryo, which occupies the entire seed after the spermoderm is removed. c c. Two 

 cotyledons separated: they are fleshy and hypogeal — i.e. remain under ground dxiring 

 genuioation. g, Gemmule or plumule, r, Badicle. 



