78 NATURAL HISTORY OF PLANTS. 



Casalpinia ; the sepals are valvate or nearly so, 1 instead of being 

 decidedly imbricated, and the anterior sepal is no larger than the 

 rest, instead of enveloping them, as in the preceding genera. The 

 fruit is a compressed, membranous, coriaceous, bivalve pod, with 

 albuminous seeds. The habit is quite different, for the three or 

 four species of this genus, from the warm and temperate parts of 

 America 2 are trees or shrubs with knotted or twisted branches, 

 axillary spinescent twigs, and bipinnate leaves, with the pinnules 

 and leaflets few and small. The flowers form short lax racemes, 

 often grouped in small numbers at the projecting nodes of the fallen 

 leaves. 



Mezoneurum* has the perianth and androceum of CamJpinia ; but 

 the flowers are far more irregular, 4 owing to the deformity of the 

 receptacle. 5 This assumes an unequal development, so that its rim 

 is very oblique, the mouth tapering like a beak towards the posterior 

 petal and the placenta. The ovary resembles that of Casaljnnia, and 

 contains two seeds and upwards. The fruit is flattened, membranous 

 and coriaceous, indehiscent or nearly so, and has its placentary edge 

 dilated all the way up into a wing which is flattened out towards 

 the free border. The seeds vary in number and resemble those of 

 CtBsalpinia. The genus Mezoneurum consists of trees or climbing 

 shrubs from tropical Asia and Africa, and Australia, 6 with bipinnate 

 leaves, and the flowers in axillary or terminal racemes. 



The flower is on the contrary, much more regular in HamatoxyloiP 

 (figs. 49-51), as regards receptacle, corolla and androceum. The 

 calyx alone has still the anterior sepal larger than the rest which it 

 envelopes ; all the sepals become reflexed on anthesis. The petals 

 are nearly similar to one another, and are imbricated as in Casalpinia. 

 The receptacle is lined with glandular tissue ; in the bottom of it is 

 inserted the gynseceum, consisting of a shortly stipitate ovary, sur- 



1 The edges are as it were bevelled, and touch gous to what is found in certain Sapititlace? 



obliquely ; or else the inner sheet of the sepal and Erylhroxylact ■ . 



alone projects beyond its edge on the side where 5 In the section Tubicah/xCM\Q.,Fl.Ind..Bat., 



it should be overlapped in the bud. i. p. 1, 1081 1, this part of the Hower forms an 



a Walp., Rep., v. 552; Ann., iv. 594 (besides elongated tube. 



Casalpinia 1 cassioides W., Enum., 444). G Bejtih., Fl. Austral., ii. 278. — H. Bn., in 



, T . . - r , , r . „., , ,_. ,, Adansonia, vi. 1!)6. — Walp., Sep., i. 811. — 



a Desf., in Mem. Mus., iv. 245, t. 10, 11. — A ' ~ ,-,, „, ,* ■• o™ 



rvn x. j •• ^o^ W A „~™ Ann., tv. t>90. — Oliv., Fl. Trop. Afr., u. 260. 



DC, Prodr., u. 484.— Endl., Gen., n. 6768 ; „ roe t ^ o.o t 



/7ir \ T , „ n ... L, ' L., Gen., n. 525. — J., Gen., 318.— Lamk., 



(Mezo)uicivn). — 15. n., Gen., 56o, n. 307. tv i ■ -(,-, o i cca hi i ,. n ,w, 



v Diet., i. 591; Snppl., i. 654; III., t. 310. — DC, 



4 The vexillary petal may not only differ from Prodr., ii. 485. — SPACn, Suit, a BiiJfon, i. 



the rest in form and size, but also bear an in- 106. — Endl., Gen., n. 6777.— B. H., Gen., 567, 



ternal appendage on the base of the limb, analo- n. 310. 



