THE BOTANY OF THE GUAYANA HIGHLAND PART III 



139 



BIGNONIACEAE 23 



This- is my twenty-second contribution to the study of the tropical American 

 representatives of the family (see Mem. X. Y. Bot. Gard. 9: 359. 1957). As 

 before, the taxa are arranged alphabetically, both by genera and species. 



Arrabidaea tuberculata DC, 



VENEZUELA: Estado Bolivar: large woody vine, young leaves canescent beneath, flow- 

 ers rose-purple, canescent, Rio Parguaza, locally frequent along river just below Raudal Maraca 

 (about 110 river km from mouth), 115 m, fl. Dec 1955, J. J. Wurdack 4' J- V> Monachino 

 40990. Colombia, Guiana, Amazonian Brazil and Peru. First record for Venezuela. 



Cremastus lachnaeus Bur. ex Bur. & K. Schum. 



VENEZUELA: Estado Bolivar: woody vine climbing on trees up to 18 m, flowers bril- 

 liant purple-red, Rio Parguaza, locally frequent at savanna margins near Pilon, 5 km northeast 

 of river mouth, 100 m, fl. Jan 1956, J. J. Wurdack $ J. V. Monachino 41132. Brazil. First 

 record for Venezuela. 



Jacaranda orinocensis Sandwith. sp. nov. 



Sect. Monolobos DC. J. kesperiae Dugand atque J. caucanae Pittier ob caly- 

 eem corollamque affinis ab ambabus habitu humili, foliorum pinnis necnon foliolis 

 paueioribus, inflorescentia ramulos hornotinos terminante, ovario glabro differt. 



Frutex vel arbor parva. 3 mm alt us; ramuli hornotini lenticellis cremeis 

 notati. parce minute lepidoti, pilis perpaucis hyalinis minutis apice glanduliferis 

 praediti, ceterum glaberrimi. Folia ramulorum inflorescentias gerentium impari- 

 . bipinnata (rarius simpliciter imparipinnata, foliolis distincte petiolulatis) , inter- 

 nodiis rhacheos 2-5 cm longis supra eanaliculato-marginatis exalatis fere glabris, 

 pinnis 3-9-jugis; foliola imparipinnatim 3-6-juga vel in pinnis imis summisque 

 1-2-juga vel etiam solitaria, rhombeo-oblonga vel obovato-oblonga vel obovata. 

 lateralia apice acuta vel obtusa usque rotunclata cuspidatula basi cuneatim 

 attenuata obliqua inaequilatera subsessilia vel plus minusve distincte (ad 5 mm) 

 petiolulata, 0.5-3.5 cm longa, 0.3-1.6 cm lata, terminalia vulgro majora elliptica 

 vel nonnunquam suborbieulari-elliptica utrinque acuta vel apice breviter acute 

 acuminata vel rotundata, ad 3.5 cm longa, ad 2.5 cm lata, omnia chartacea, infra 

 pallida glauceseentia, fere glabra sed supra secus nervos minute puberula atque 

 subtus basin costae versus saepe pilosula. nervis venulisque supra planis vel 

 impressis subtus prominulis. Folia ramulorum sterilium maxima, fere glabra. 

 40-45 cm longa, 30-40 cm lata, paribipinnata. internodiis rhacheos 4-6.5 cm 

 longis subteretibus exalatis supra peranguste vix obvie nec profunde canali- 

 culatis, pinnis 6-jugis; foliola imparipinnatim 3-9-juga, lateralia trapezoideo- 

 oblonga apice acuta mucronata basi acuta cuneatim attenuata. subsessilia vel 

 distincte ad 3 mm petiolulata, 2-4 cm longa, 1-1.8 cm lata, terminalia lanceolato- 

 elliptica apice conspicue acuminata basi longe attenuata ad 5.5 cm longa ac ad 

 2 cm lata, ceterum iis sub inflorescentiis dispositis similia sed rigidiora. Inflores- 

 centia apice ramulorum hornotinorum terminalis, in exemplis visis 5-12 cm 

 longa. 6-9 lata, velut ramuli minute parcissime lepidota ceterum glabra ; bracteae 

 primariae foliaceae anguste elliptico-lanceolatae vel lineari-spathulatae petio- 

 latae, ad 1.3 cm longae. 1.5-3 mm latae, superiores gradatim breviores; pedicelli 

 ad 5 mm longi, saepe cernui. Calyx saltern ad medium vulgo ultra medium 

 divisus. extra parce inaequaliter lepidotus ceterum glaber ; lobi oblong:i, spathu- 

 lato-oblongi vel triangulari-lanceolati, apice acuti vel obtusi. 3.5-5 mm longi. 



23 By N. Y. Sandwith. 



