114 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



Feb 5-6, 1955, Bassett Maguire, W. M. C. Bagshaw, & Celia K. Maguire 40582 

 (NY). 



M. parvulum has shorter stems, obtuse to subacute leaf-blades with obtuse to 

 broadly acute bases, and no stipuliform cauline appendages. The leaf shape, lack 

 of stipules, and many-flowered inflorescences will distinguish M. montanum 

 Gleason and depauperate specimens of M. cristatum Tr. and M. fruticosum 

 Gleason. 



Macrocentrum longidens (Gleason) Wurdack, comb. nov. 

 Diolena longidens Gleason, Mem. N. Y. P>ot. Gard. 8: 140. 1953. 



Macrocentrum repens (Gleason) Wurdack, comb. nov. 

 Diolena repens Gleason, Bull. Torrey Club 75: 541. 1948. 



For both these taxa I have now been able to examine buds sufficiently mature 

 to show the stamen structure. The affinity of both with the next-described species 

 is evident, in aspect as well as in floral details; all three have a ciliate short 

 ovarial collar, tin 1 same type of anther and stamen appendages, and the same 

 kind of bypanthial pubescence. These 1 transfers eliminate the genus Diolena from 

 the Guayana Highland flora. M. repens is now also known from the slopes of 

 Ptari-tepui (Steyermark 59461, Maguire & Wurdack 33928) and from Mt. 

 Ayang-anna (Maguire, Bagshaw, & Maguire 40584- A) . 



Macrocentrum neblinae Wurdack, sp. nov. 



M. longidenti (Gleason) Wurdack valde affinis sed plerumque robustius, 

 foliis maioribus in proportione angustioribus apice anguste acutis sepalorum 

 lobis interioribus ovatis hebeti-acutis. 



Herba basi lignosa alt, ad 60 cm superne ramosa, ram is teret ibus glabris. 

 Folia opposita in quoque .jugo valde dimorphica primum cum glandulis pallido- 

 rubris sparse ornata demum marginibus exceptis glabra; folia minora sessilia 

 ovate acuta ad 8 X 3 mm uninervia margine sparse denticulato-ciliata ; folia 

 maiora brevipetiolata (petiolo plerumque ca. 1 mm longo) 2-4 X 0.5-1.3 cm, 

 lanceolata apice acute basi cuneata paulo (0.5-1 mm) triplinervia, marginibus 

 de medio apicem versus sparse denticulatis, denticulis 1-2 mm inter se distant ibus 

 uniciliatis cilio appresso. Flores 5-meri solitarii, pedicello ca. 2-3 mm longo, 

 dense glanduloso-puberulo basi bibracteolato bracteolis lanceolatis glabris. 

 Ilypanthium (ad torum) 2-2.8 X 2.2-2.7 mm modice glanduloso-puberulum 

 pilis ca. # 5 mm longis. Calyx vix (0.2 mm) coalitus. lobis interioribus 2-2.5 X 

 1.6-1.9 mm. ovatis hebeti-acutis sparse glanduloso-puberulis margine glanduloso- 

 ciliolatis, dentibus exterioribus aristatis arista 2-2.5 mm eminenti (in fructu ad 

 3 mm) basim versus parce glanduloso-scabridula. Petala (paulo immatura) 

 4.7 X 2.7 mm ovata acuta breviapiculata glabra. Stamina inconspicue dimor- 

 phica; filamenta matura desunt ; antherae 2.6 mm longae, basi 0.5 mm latae, 

 paulo subulatae poro 0.2 mm lato, connectivo ad insertionem filamenti 0.3 mm 

 proclucto, appendiee dorsali 0.6 mm longa hebetiacuta. Stylus 4.5 X 0.2-0.3 mm ; 

 stigma paulo capitulatum 0.35 mm latum; ovarium 3-loculare glabrum apice in 

 collum breviciliatum 0.5 mm pf oductum ; semina 0.5 X 0.3 mm,'laevia pyrami- 

 data paulo angulata. 



Type: Mowers white, locally common on boulders in stream courses in talus 

 forest between Camps 2 and 3, elev. 250-650 m, Cerra de la Neblina, Terr. Ama- 

 zonas, Venezuela, Dec 22, 1953, Basset Maguire, John J. Wurdack, & George S. 



