544 



FABACE^. 



[Perigynous Exogens. 



Order CCIX. FABACEiE.— Leguminous Plants. 



Leguminosse, Juss. Gen. 345. (1789) ; Bronn. Diss. 

 Endl. Gen. p. 1253. 



(1822) ; Prodr. 2. 93 ; Walpers in Linncea, xiii. 

 Meimi. Gen. p. 84. 



Diagnosis. — Rosal Exogens, with polypetalous or apetalom flowers, a papilionaceous co- 

 rolla or a leguminous fridt, and a solitary carpel lohose style proceeds from the apex. 



Herbaceous plants, shrubs, or vast trees, extremely variable in appeai'ance. Leaves 

 alternate, most commonly compound, occasionally marked ^^'ith transparent dots ; petiole 



tumid at the base. Stipvdes 2 at the 

 base of the petiole, and 2 at the base 

 of each leaflet. Pedicels usually ar- 

 ticulated, vAih. 2 bractlets imder the 

 flower. Calyx 5-parted, toothed or 

 cleft, inferior, with the odd segment 

 anterior; the segments often unequal, 

 and variously combined. Petals 5, 

 or by abortion 4, 3, 2, 1 , or none, 

 inserted into the base of the calyx, 

 either papilionaceous or regularly 

 spreading; the odd petal, if any, pos- 

 terior. Stamens definite or indefinite, 

 perigj-nous, rai'ely hypogynous, 

 either distinct or monadelphous, or 

 diadelphous ; very rarely triadel- 

 phous ; anthers versatile. Pistil 

 simple, superior, 1 -celled, 1- or many- 

 seeded, commonly consisting of a sin- 

 gle carpel, but occasionally of 2, or 

 even of 5 ; style simple, proceeding 

 from the upper margin ; stigma sim- 

 ple. Fruit either a legume or a 

 drupe. Seeds attached to the upper 

 suture, sohtary or several, occasion- 

 ally with an aril ; embryo with or 

 without albumen, either straight or 

 with the radicle bent upon the coty- 

 ledons ; cotyledons either remaining 

 vmder gromid in germination, or 

 elevated above the ground, and be- 

 coming green hke leaves, always 

 very large in proportion to the radicle, 

 and very often amygdaloid. 



The most common feature of Le- 



Fig. CCCLXX. 



guminous plants is to have what are called papilionaceous flowers ; and when these exist, 

 no difficulty is experienced in recognising them, for papihonaceous flowers are foimd 

 nowhere else. Another character is to have a leguminous finiit ; and by one of these 

 two charactei's all the plants of the Order are known. It is remarkable, however, tliat 

 one or other of these distmctions disappears m a gi'eat many cases. CEesalpmiese have 

 an irregular flower, mth spreadmg petals and stamens adhermg to the calyx ; others 

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

 regular flowers and indefinite hypogjuous stamens. Detariimi, Dipteryx, and others, 

 instead of a legume, bear a fniit not distmguishable from a di'upe. This last cii'cmn- 

 stance is easily to be imderstood, if we bear m mind that a legume and a dinipe differ 

 more in name than reality, the latter bemg formed upon precisely the same plan as the 

 former, but with this modification, that its pericarp is tliickened, more or less fleshy on 

 the outside and stony on the mside, 1 -seeded, and indehiscent. Hence some of the 



Fig. CCCLXX.— Adenocarpus frankenioides. 1. the standard, ■svings, and keel split open; 2. the 

 stamens ; 3. a cross section of a seed ; 4. a legume, with a portion of one of the valves turned back. 



