1953] 



REVISION OF MACROLOBIUM 



335 



The new species is named in honor of the collector of the type material, W. A. 

 Archer, Curator of the Herbarium of the Bureau of Plant Industry at Beltsville, 

 Maryland, and collector of note in northern South America. 



48. Macrolobium pittieri (Rose) Schery, Ann. Mo. Bot. Gard. 38: 33. 1951. Fig- 

 ure 12. 



Vouapa Pittieri Rose, N. Am. Flora 23: 226. 1930. 



Branchlets glabrous. Petioles 3-6 mm. long, glabrous. Leaflets 28-32.5 cm. 

 long, 8.5-11 cm. wide, sessile, subequilateral, oblanceolate, the base inequilat- 

 eral, the lower side obtuse and much wider than the acute upper side, the apex 

 caudate-acuminate, the margin entire or irregularly undulate; upper surface gla- 

 brous, very minutely puberulous beneath on the costa and the primary veins, epunc- 

 tate; costa salient above, the costa and primary veins salient beneath, the ven- 

 ules prominulous above, conspicuous beneath. Inflorescences to 3.5 cm. long, gla- 

 brous, the bracts 2.5 mm. long, 1 mm. wide, triangular, the pedicels about 4.5 mm. 

 long; bracteoles 12 mm. long, 4 mm. wide, oblanceolate, concave, rounded-obtuse, 

 glabrous. Hypanthium 10 mm. long on a 3 mm. stipe, glabrous. Sepals 17-18.5 mm. 

 long, 4 mm. wide, oblong, obtuse, concave, sparsely and irregularly ciliolate, oth- 

 erwise glabrous. Petal blade 42 mm. long, 15 mm. wide, elliptic, the claw 5 mm. 

 long, glabrous externally, sparsely pilosulose within on the lower half of the 

 costa. Filaments about 25 mm. long, villose basally, the anthers 5 mm. long, 2 

 mm. wide. Stigma capitate. Style 24 mm. long, pilosulose basally. Ovary 3-4 mm. 

 long, 1-1.5 mm. wide, oblong, pilosulose on the margins, laterally glabrous, 6- 

 ovulate; free portion of the gynophore 2 mm. long, pilosulose adaxially. Fruit gla- 

 brous, the seeds 3*3. 5 cm. long, 2.5 cm. wide, obovate, the testa very membran- 

 ous and venulose. 



Type Collection: H. Pittier 4355, "Plain of Sperdi, near Puerto Obaldla, San 

 Bias coast; near sea level," Panama, Sept. 1911 (HOLOTYPE US, isotypes F, 

 GH, NY). 



One might expect that this species would show greater relationship to the 

 other Panamanian species than to any other. Such is not the case, however, for it 

 is much more nearly allied to M. archeri of Colombia. From the latter it may be 

 separated by its unguiculate, larger petal, its shorter hypanthium, its smaller gla- 

 brous bracteoles, and its caudate-acuminate leaflet apices. 



Pittier published a description of M. floridum based on the specimen cited 

 above (Contr. U. S. Nat. Herb. 18: 233. 1917) but Rose recognized that the mater- 

 ial actually represented a new taxon. Consequently, he described it as a new spe- 

 cies, basing it on Pittier's collection and naming it for the collector. It rested 

 under the generic name Vouapa until Schery transferred it to the proper genus in 

 1951. 



SPECIES DUBIA 

 1. Vouapa simira Aubl. Pi. Guian. 1: 27, pi. 8. 1775- 

 Vouapa violacea Lam. Encycl. 97. 1791. 



Macrolobium Simira (Aubl.) Gmel. Syst. Nat. ed. 13. 2: 93. 1796. 

 Macrolobium sphaerocarpum Willd. Sp. PI. 1: 186. 1797. 



Aublet's plate representing this species shows unijugate leaves, the leaflets 

 of which are equilateral and petiolulate. In addition to the foliage, only a single 

 legume was depicted and this was orbicular in outline. The only recognized spe- 

 cies possessing such leaflets is one from central Brazil, M. arenarium. In con- 

 trast to the orbicular legumes shown in Aublet's figure, the fruits of M. arenarium 

 are elongate-oblong. 



