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MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[Vol. 9, No. 3 



penninerviis utrinque prominenter reticulato-venosis, nervis lateralibus utroque 

 latere 8-10 costa media subtus elevata, plerumque glabris, foliorum juvenilium 

 costa media supra parce puberula excepta; capitulis solitariis terminalibus 

 sessilibus homogamis 10-21-f loris; involucro pyriformi basi angustato, 4-4.5 cm 

 longo 1.5-2 cm lato, ca. 10-seriato, phyllariis valde gradatis adpressis extus 

 fulvo-strigillosis, inferioribus coriaceis late ovatis obtusis vel acutiusculis, 

 10-13 rnm longis 8-9 mm latis, superioribus oblongo- vel late lanceolatis acu- 

 tiusculis vel acutis, 17-21 mm longis 5-7 mm latis, supremis linearibus vel 

 lineari-lanceolatis, 25-30 mm longis 2-3 mm latis; receptaculo piano alveolato 

 glabro, 5-6 mm diam. paleifero, paleis 3-4, chartaceis deciduis subulato-setaceis, 

 32-35 mm longis 1 mm latis, extus marginibusque hirsutulis; floribus 19-21 

 actinomorphicis albidis; corollis 32 mm longis glabris, tubo hypocrateriformi, 

 20-22 mm longo basi 1.5 mm lato apice 2.5 mm lato, quinquelobato, lobis subae- 

 qualibus anguste linearibus, 13-15 mm longis 1 mm latis, acuminatis valde 

 revolutis apice marginibusque incrassatis; filamentis in sinibus affixis, 5-6 mm 

 longis, antheris 11-11.5 rnm longis, appendicibus terminalibus triangularibus 

 acutiusculis 1 mm longis, caudicibus sagittatis, 2.5 mm longis, lineari-lanceo- 

 latis falcato-acuminatis remote retrorso-serrulatis; pappo 18-20 mm longo, sordido, 

 setis 5-6-seriatis longioribus apice dilatatis hispidulis; achaeniis nigris lineari- 

 cylindricis prismaticis 5-7-angulatis, 11 mm longis 2 mm latis, glabris. 



TYPE: common on forested west-facing slopes with sandstone boulders, 

 between camp 2 and camp 3, northwestern part of Abacapa-tepui, Chimanta-Massif , 

 Boh'var, Venezuela, 850-1100 m alt., April 18, 1953, Julian A. Steyermark 75410 

 (holotype F; isotype NY). Paratype: along southwest-facing sandstone bluffs of 

 Chimanta-tepui (Torono-tepui), near southern corner, Chimanta Massif, 1700 m alt., 

 May 19-20, 1953, Steyermark 75479. 



Chimantaea Maguire, Steyermark & Wurdack, gen. nov. 



Capitulis solitariis, terminalibus, majusculis, multifloris (20-50); phyllariis 

 gradatis acutis, multiseriatis; receptaculo plano-convexo pubescenti; paleis paucis 

 (2-5), marginalibus; corollis actinomorphicis, membraneis, tubo 5-nervato, intus 

 ad sinus pilosis, lobis erectis vel recurvatis, plus minusve barbellatis, 2-nervatis, 

 tubum excedentibus; filamentis in sinibus affixis, antheris sagittatis, appendicibus 

 caudatis linearibus liberis; granis pollinis luteis tricolporatis sulcis longiacutis, 

 prolatis vel prolato-sphaeroidiis, spinulosis, axibus polaris 50-55 U- longis; 

 stylis sursum asperulis, ramis erectis brevibus indifferentiatis; achaeniis prisma- 

 ticis 10-costatis, glabris vel pubescentibus; annulo deficienti; corona 5-partito- 

 lobata, lobis saepe ad basim liberis; pappo ?-4-seriatis, setis inaequaliter 

 longis, ad basim compressis, sursum barbellatis, ad apicem subgeniculatis, 

 appendicibus aristatis. 



Typus: Chimantaea mirabilis Maguire, Steyermark & Turdack. 



Key to the Sections and Species of Chimantaea 



1. Heads not imbedded in woolly pubescence and apical leaves, the involucre 

 exposed; leaves broadly oblanceolate; branched, thick-stemmed shrubs; 

 sect. Cinerea. 



2. Achenes and receptacle densely villose or pilose; heads 2.5—3.5 cm long; 



phyllaries at length strongly recurved or reflexed. i. Chimantaea cinerea. 



2. Achenes and receptacle glabrous; heads 3.5-4.0 cm long; phyllaries ascend- 



ing, neither recurved nor reflexed. 2. Chimantaea similis. 



1. Heads imbedded in copious woolly pubescence and apical leaves, the involucre 

 partly or wholly obscured; sect. Chimantaea. 



3. Achenes and receptacle densely villose or pilose; leaves spreading or ascend- 



ing, not marcescent. 



