1957} 



THE BOTANY OF THE GUAYANA HIGHLAND— PART II 



345 



60 km above mouth, 100-140 m elev., Nov. 1953, Maguire, Wurdack & Bunting 

 36676; frequent in savanna on right bank, 50 km above mouth, Feb. 1954, Maguire, 

 Wurdack & Bunting 37572; frequent in savanna on left bank of Cano Hechimoni, 

 8 km above mouth, 100-130 m elev., Feb. 1954, Maguire, Wurdack & Bunting 37643. 



There is every good reason for relating this species to M. discolor and to 

 Al multijugum, although it is much nearer the former. From M. multijugum the 

 new species may be separated most easily on the smaller number of leaflet-pairs, 

 the short peduncles, the larger flowers, and the differently shaped fruits of M. 

 longipes (the specific epithet refers to the unusually long pedicels). It differs 

 from M. discolor by its punctate leaflets, glabrous inflorescence and flowers, 

 larger flowers, and generally fewer pairs of leaflets. 



Macrolobium unifoliolatum Cowan, sp. nov. (Fig. 64.) 



Arbuscula vel arbor gracilis 7 m alta, ramulis minute puberulis. Petiolus 3-6 

 mm longus, minute puberulus, teres, stipulis caducis. Folia unifoliolata, foliola 

 sessilia, lamina coriacea, 13.5-22.5 cm longa, 4.5-8 cm lata, lanceolata ad 

 elliptico-lanceolata ad oblongo-elliptica, aequilateralis, ad basim obtusa ad 

 subobtusa, ad apicem acuminata, glabra supra, infra glabra vel ad costam minute 

 puberula, punctata; costa saliens vel leviter impressa supra, infra saliens, venis 

 venulisque prominentibus. Inflorescentiae 2-12 cm longae, terminales vel axillares, 

 axe minute puberulo, pedunculis subnullis; bracteis deciduis, triangularibus, ca. 

 1 mm longis et latis, intus glabris, extus glabris vel puberulis, minute ciliolatis; 

 pedicelli 3.5-9 mm longi, puberuli vel glabri; bracteolis lanceolatis, 9-15 mm 

 longis, 3-4 mm latis, longo-acuminatis, glabris vel extus puberulis. Hypanthium 

 cupulare, 2 mm longum, glabrum, sepalis 4, glabris vel ciliatis et dorsualiter 

 pilosulis ad apicem, dimorphis, sepalo dorsuali 5 mm longo, 2.5 mm lato, oblongo- 

 lanceolato, acuto, caeteris 3.5-4 mm longis, 1-1.5 mm latis, acuminatis et plus 

 minusve erosis. Petalum album, lamina rotunda vel subrotunda, 3.5-5.5 mm longa, 

 4.5-5.5 mm lata, glabra, unguiculo 4.5 mm longo, intra villoso. Filamenta 10-12.5 

 mm longa, ad basim sparse villosa. Stigma capitellatum, stylus 12.5-20 mm 

 longus, ad basim pilosulosus, ovarium ellipticum, pilosulosum. Fructus ignotus. 



TYPE: petal white; stamens red; slender tree 7 m tall in riverine forest just 

 south of Maroa, Rio Guainla, Terr. Amazonas, Venezuela, 120-140 m alt., Nov. 

 28, 1953, Bassett Maguire, John J. Wurdack & George S. Bunting 36445 (NY). 



Macrolobium unifoliolatum var. schultesii Cowan, var. nov. 



A var. unifoliolatum petiolis 3-4 mm longis, foliolis ad costam puberulis, 

 costa supra salienti, inflorescentia 6.5-12 cm longa, axe dense puberulo, bracteis 

 puberulis extus, pedicellis 4-9 mm longis, dense puberulis, bracteolis 9-10.5 mm 

 longis, extus dense puberulis, sepalis dorsualiter pilosulosis ad apicem, petali 

 lamino rotundo, 5.5 mm diametro, filamentis 12.5 mm longis, stylo 12.5 mm longo 

 differt. 



TYPE: bush, flowers white, Raudal Yayacopi (La Playa) and vicinity, about 

 800 ft alt., Rio Apaporis, Amazonas- Vaupes, Colombia, April 15, 1952, Richard 

 E. Schultes & 1. Cabrera 16209 (NY). Paratype: same data and collectors, 16940. 



This species is so utterly different from any previously described, in respect 

 to the leaves, that the casual observer may even fail to relate it to this genus. 

 Not only are the leaves unifoliolate but the leaflet is equilateral and differently 

 shaped from those of most of the other species in the genus. In leaflet shape, at 

 least, the new species is similar to members of the M. campestre-M. arenarium 

 complex but its connection with any known species is remote. 



The aspect of the typical variety and of variety schultesii is very similar, 

 and it was originally thought that this material was quite uniform. It will be noted, 



