46 MERRILL! SYSTEMATIC POSITION OF THE "RAIN TREE 



>j 



to him. Dr. Grisebach, who had the advantage of studying the tree 

 in the living state, at once recognized that it cannot possibly be a 

 Pithecolobium and placed it in Calliandra, no doubt owing to the sutures 

 of the pod being thickened as in that genus. That the pods are sep- 

 tate and indehiscent militates however against his proposal, for the 

 crucial test of a Calliandra is that its pods, which may not be septate, 

 shall dehisce elastically from apex to base. The Index Kewensis has 

 therefore replaced the " Rain-Tree" in Pithecolobium; this however is a 

 step which in turn similarly mars the generic limits of that group, since 

 the pods of Pithecolobium must not be septate. The writer places the 

 species with more confidence in Enterolobium, owing to its possessing 

 the septate pods characteristic of that genus. The pulpy, in place of 

 spongy at length indurated mesocarp, and the shortly pedicelled in 

 place of sessile florets, cannot, in view of the variability of these char- 

 acters within adjacent genera, be considered more that comparatively 

 trivial deviations from the hitherto recognized characters of Entero- 

 lobium. The writer is unable, both on academic and on practical 

 grounds, to agree with the proposal, made by some botanists, to amal- 

 gamate Calliandra, Pithecolobium, Enter •olobium and Albizzia. 



I am in entire agreement with Prain, except that after having 

 had an opportunity to study several species of Enter olobium, I 

 am thoroughly convinced that, although the alliance of Pithe- 

 colobium Saman Benth. is unquestionably with Enterolobium and 

 not with Pithecolobium, it represents a group generically distinct, 

 and that if placed in Enterolobium it will be anomalous in that 

 genus, although not to the same extent as in Pithecolobium. 

 I propose therefore to raise to generic rank Bentham's section 

 Samanea, which is typified by the species under consideration. 

 I am confident, however, that many of the species ultimately 

 placed by Bentham in this section are not congeneric with 

 Samanea as typified by Pithecolobium Saman, and I am equally 

 confident that some of them cannot be logically considered as 

 representatives of the genus Pithecolobium. Several species are, 

 however, unquestionably congeneric with Samanea and should be 

 transferred here. 



Samanea (Benth.) Merrill, gen. nov. 



Pithecolobium Mart. § Samanea Benth. in Hook. Lond. Joum. Bot. 3: 

 197. 1844.— Trans. Linn. Soc. 30:585. 1875. 

 Flores 5-meri, hermaphroditi. Calyx infundibuliformis, breviter 

 lobatus. Corolla subinfundibuliformis, petalis usque ad medium con- 

 natis, valvatis. Stamina °° , basi in tubo connata, longe exserta; 

 antherae parvae, eglandulosae. Ovarium sessile, °°-ovulatum, stylis 



