260 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 8, No. 4 



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nensis has not been seen, there are two subsequent collections from Surinam 

 which match Aublet's plate well and are accepted as representing this taxon. 



Scopoli renamed Vouapa in 1777, calling it Kruegeria, and in 1789 Schreber in- 

 cluded both Vouapa and Outea under a new name, Macrolobium, which gained gen- 

 eral acceptance. In 1805 J. St.-Hilaire and in 1891 Taubert used Aublet's original 

 generic names, but St.-Hilaire changed their spelling to Vuapa and Utea. The le- 

 gitimate generic name was finally resolved by legislative action in the conserva- 

 tion of Macrolobium against Outea, Vouapa, and Kruegeria in 1935. 



Between 1775 and 1870 very little was added to the knowledge of the genus 

 aside from the descriptions of a few new species and the renaming of some of the 

 older ones. Vogel (1837) described two new species, M. pendulum and M. lati- 

 folium, and at the same time created two sections. His first section included both 

 Vouapa and Outea but he presented no name for it; the second section, which he 

 called Scytodium, included only his new species, M. latifolium. 



By 1870 some nine species had been proposed, and in that year Bentham pub- 

 lished the first critical study of the genus in Flora brasiliensis , adding a number 

 of new species based on Spruce's collections in Brazil. In this review he recog- 

 nized only the name Macrolobium, relegating Outea and Vouapa to synonomy. 



The following years witnessed the addition of numerous new species as north- 

 ern South America became better known floristically. Both O. Kuntze and Taubert 

 in 1891 placed most of the then known species in the genus Vouapa ("Vuapa" of 

 Kuntze). Of more consequence was the treatment of the genus by Britton and Kil- 

 lip (1936). In this publication these authors maintained Outea as a genus distinct 

 from Vouapa, the latter being considered as a synonym of Macrolobium. At the 

 same time they established a new genus, P seudovouapa, to include the single 

 species NL stenosiphon Harms. The writer has found no morphological grounds for 

 the recognition of P seudovouapa and it is accordingly treated here as a synonym 

 of Macrolobium. To be sure, there are abundant differences to distinguish its type 

 species from all other species in the genus, but none is of generic magnitude. 



Both Ducke and Pittier presented reviews of the genus (1941). Ducke's treat- 

 ment included only the species of the "Amazonian Hylaea," and in it he presents 

 keys to the species, general remarks concerning the plants, and the citation of 

 Ducke collections. Pittier's review was somewhat more complete but included 

 only the species of Venezuela. He included keys, brief descriptions, citation of 

 a few specimens for each species, and the descriptions of three new species, one 

 of which was conspecific with an earlier species. 



Miss Amshoff (1948), working at Utrecht on Maguire's legume collections from 

 Surinam, published the descriptions of two new species and one new variety; she 

 also gives a key, but only to the species of Guiana. 



MORPHOLOGY 



Habit. Both shrubs and trees occur and each taxon is rather constantly of one 

 or the other form. The minimum stature is realized in M. savannarum, which is 

 characteristically a low shrub, often less than a meter in height when fully ma- 

 ture. At the other extreme, individuals to 35 m. tall were recorded by Krukoff for 

 M. campestre var. arboreum. Many of the arborescent species have a spreading, 

 more or less flat-topped crown. 



Stipules. These structures occur in pairs at the base of the petioles but are 

 most frequently caducous; in a few taxa (M. huberianum and M. pendulum) their 

 persistence has been a useful character. In form, they vary from small subulate 

 structures to large foliaceous ones; where possible their form and size have been 

 used in the taxonomy of the genus, for both characters are quite stable. 



