1953} 



REVISION OF MAGROLOBIUM 



323 



ity; costa subimpressed on the upper surface, salient beneath, the venules promi- 

 nent. Inflorescences to 7 era. long, glabrous, the peduncles 5-6 mm. long; pedi- 

 cels 6-8 mm. long, glabrous; bracteoles 10-11 mm. long, 5 mm. wide, oblong and 

 cuspidate or elliptic and acute, glabrous, coriaceous. Hypanthium 2 mm. long on 

 a stipe about 1 mm. long, glabrous. Sepals four, 7-8 mm. long, 2.5-3 mm. wide, 

 lanceolate or oblong-lanceolate, acute, slightly concave, cilioiate in the apical 

 portion. Petal blade 6 mm. long, 7.5 mm. wide, transversely oval, the claw 5-6 

 mm. long, auriculate basally, glabrous externally, cilioiate on the lower portion 

 of the claw, villose within on the claw and up to the center of the blade. Fila- 

 ments 16.5 mm. long, villose basally. Stigma capitate. Style 13 mm. long, gla- 

 brous. Ovary 2.5 ram. long, 1.5 ram. wide, oblong, glabrous, 1-2-ovulate, the gyno- 

 phore 2.5-3 mm. l° n g> glabrous, inserted midway on the adaxial hypanthial wall. 

 Fruit unknown. 



Type Collection: A. Ducke (H.J.B.R. No.) 35193, "Igarape Macacury, Rio Ne- 

 gro, Cucuhy," Amazonas, Brazil, September 1935 (HOLOTYPE RB, isotypes G, 

 P, U, US). 



Macrolobium palustre is obviously related to M. pendulum but differs in so 

 many characters, both quantitative and qualitative, that it has been regarded as 

 specifically distinct, although the first reaction was to treat it as a variety within 

 M. pendulum. In addition to differing by the frequent occurrence of bijugate leaves, 

 M. palustre has caducous stipules, longer petioles, longer sepals and petal claw, 

 and basally villose filaments. Also, whereas M. pendulum is distributed along the 

 lower basin of the Amazon River, this species is known only from the upper Rio 

 Negro region. 



36. Macrolobium savannarum Cowan, sp. nov. Figure 11. 



Arbuscula ad 1 m. alta, ramulis minute et sparse puberulis. Stipulae caducae, 

 2 mm. longae, 0.5 mm. latae, subulatae, acuminatae, sparsissirae ciliolatae. Peti- 

 olus 1.5-4 ram. longus, minute puberulus. Foliola 1.5-5.5 cm. longa, 1-2.5 cm. 

 lata, inaequilateraliter subfalcato-elliptica, ad basim inaequilateralia, latere in- 

 feriore obtuso sed superiore acuto, ad apicem acuta et extremitate obtusa, glabra, 

 epunctata; costa Ieviter saiienti, venulis utroque conspicuis. Inflorescentiae 1.5- 

 3cm. longae, glabrae, pedunculo 1-2 mm. longo; bracteis caducis; pedicellis 5-15 

 mm. longis, glabris; bracteoli 9-11 mm. longi, 4-7 mm. lati, oblongi, obovati vel 

 oblongo-obovati, glabri, apiculati, intus carnosissimi. Hypanthium 1.5-2 mm. 

 longum, glabrum. Sepala quattuor, 4-8 mm. longa, 1.5-4 mm. lata, oblonga vel lan- 

 ceoiata, ad apicem eroso-dentata, glabra. Petali lamina 6-7.5 mm. longa, 6.5 mm. 

 lata, orbicularis, unguicilo 5-8 mm. longo, alato, haud auriculato; 1-4 petalodia 

 4-7.5 mm. longa, linearia vel lineari-oblanceolata. Filamenta 13.5-15.5 ram. longa, 

 glabra. Stigma capitellatum. Stylus 10-13.5 mm. longus, glaber. Ovarium 2-2.5 

 mm. longum, 1-1.5 mm. latum, oblongum, glabrum, (2-)3-ovulatum, gynophoro 2-2.5 

 mm. longo, glabro. Fructus ignotus. 



Type Collection: B. Maguire, R. Cowan, & /. Wurdack 30540, "Yapacana Sa- 

 vanna, base of Cerro Yapacana, Flo Orinoco," Amazonas, Venezuela, Jan. 1951 

 (HOLOTYPE NY, isotypes F, G, K, MO, U, US). 



Additional Specimens: Same data, Maguire, Cowan & Wurdack 30505 (IAN, NY, VEN). 



This new species is most nearly related to M. pendulum but there are several 

 very distinct differences separating them. M. savannarum has caducous stipules, 

 epunctate leaflets, and it is a low shrub of southwestern Venezuela. M. pendulum 

 has persistent stipules, often punctate leaflets, and it is a tree 8-20 m. tall in 

 the Amazon Delta region and southern Amazonas in Brazil. 



This species was the dominant shrub in the open wet savanna where it was 

 growing but was not found in the semi-savanna areas nearer the river. The soil of 



