1953] 



REVISION OF MACROLOBIUM 



309 



NY, US); Sachachoro, near Yurimaguas, Oct. 1931, Mexia 6088 (F, G, GH, MO, NY, U, UC, 

 US). 



VENEZUELA: San Antonio, Rio Orinoco, Amazonas, April 1942, Williams 15076 (F, 

 US, VEN). 



Vernacular Names: Brazil: "faveira." 



This species, the two preceding ones, and the one following have been inter- 

 preted as comprising a complex which may have diverged from the M. campestre- 

 M. arenarium line of relationship. However, this disposition is admittedly more a 

 matter of convenience than of any very impressive morphology. 



Unquestionably, the nearest relative of M. unijugum is the following species, 

 VI. klugii. The leaflets of M. unijugum are quite different in shape and are borne 

 on generally longer petioles, and its ovary is more or less pubescent. 



The typical variety has a somewhat different aspect, largely because the 

 costa and primary veins are strongly impressed on the upper leaflet surface, while 

 only the costa is impressed in the other varieties. Its shorter inflorescences, fas- 

 ciculate in loose clusters, also lend a distinctive aspect to the typical form. 

 These characters separate it from its nearest relative, variety mucronatum, but 

 the latter also has mucronate bracteoles, longer anthers, and leaflets which are 

 sometimes petiolulate. 



Var. fanshawei is named in honor of Mr. D. B. Fanshawe, Conservator of For- 

 ests of British Guiana and outstanding student of the flora of this region. It is to 

 be distinguished from the other varieties by its five, smaller sepals, which are 

 somewhat dimorphic, and by its disjunct geographic distribution. 



Inga unijuga was described in 1845 on the basis of Poeppig 2801, although 

 this number (nor any other number) was not cited in the original description. In 

 1870 Bentham described Macroiobium limbatum with a Spruce collection as the 

 basis and it was not recognized that the two were synonymous until 1891 when 

 Kuntze transferred the species to Vouapa as V. unijuga. There is no doubt that 

 the two names apply to the same taxon after one has studied both collections. 



The Poeppig collection was very probably sterile. The initial description 

 states that the portion relating to the legume was taken from field notes. Whereas 

 the flowers of other species described by Poeppig and Endlicher at the same 

 time and in the same place were quite abundantly characterized, those of /. uni- 

 juga were described only as "Flores albi." It is probable that Poeppig only ob- 

 served the flower color without obtaining flowering material. In fact, the label on 

 the Paris sheet specifically states that he made the collection without flowers 

 and fruit ("sine fl. et fr. legi"). 



Besides the sheet at Paris, which is identified only as "Inga?", there are 

 two sheets at Vienna, one of which is annotated as "Inga unijuga Poepp." and is 

 regarded as the holotype. 



26. Macrolobium klugii Cowan, sp. nov. Figure 8. 



Arbustum 2 m. altum, ramulis glabris. Petiolus 7-9 mm. longus, leviter sul- 

 catus, glaber. Foliola 11.5-17 cm. longa, 2.5-4.5 cm. lata, subaequilateralia, 

 angusto-elliptica, ad basim inaequilateralia, acuta, decurrentia, ad apicem acuta 

 et extremitate acuta, glabra, epunctata; costa leviter impressa supra, infra val- 

 dissime salienti, venulis prominulis. Inflorescentiae circa 4 cm. longae, termi- 

 nales, axe minutissime puberulo; bracteis caducis, 1 mm. longis et latis, ovatis, 

 caudato-acuminatis, intus glabris, extus minuto-puberulis, ciliolatis; pedicelli 

 4-5 mm. longi; bracteolis 6.5 mm. longis, 3 mm. latis, ellipticis, intus glabris, 

 extus minutissime puberulis. Hypanthium 2 mm. longum, sessile, glabrum. Sepala 

 quattuor, 5-5.5 mm. longa, 1.5-2 mm. lata, oblonga, vel ovali-elliptica, obtusa, 

 glabra. Petalum ignotum. Filamenta 17.5 mm. longa, ad basim sparse villosa. 

 Stigma nonnihil peltatum. Stylus 12.5 mm. longus, glaber. Ovarium 2 mm. longum, 



