Tetrapterys gracilis W.R.Anderson
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Authority
Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.
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Family
Malpighiaceae
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Scientific Name
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Description
Latin Diagnosis - Frutex 0.2-0.6(-1) m altus, ramis gracilibus primum sericeis plerumque mox glabratis. Lamina foliorum majorum 3.5-6.5(-10) cm longa, 0.7-2.8 cm lata, ovata vel anguste ovata, basi cuneata vel obtusa, apice attenuata, acuminata, vel acuta, saepe reflexa, mox glabrata, margine aliquot glandulis impressis munita, reticulo subtus vel utrinque prominulo; petiolus 3-6(-9) mm longus, sparsim sericeus vel glabratus, eglandulosus vel 2-4 glandu;os parvis munitus; stipulae nullae vel minutae, ca 0.1 mm altae, interpetiolares prope basim petioli. Inflorescentia pseudoracemus axillaris 1-3(-4.5) cm longus, floribus decussatis 4-12(-22), bracteis 0.7-1.2 mm longis, ca 0.5 mm latis, eglandulosis, pedunculo 1-4 mm longo, bracteolis 0.8-2 mm longis, 0.6-1.2 mm latis, apice vel sub apice peduncuH portatis, una vel ambabus saepe uniglanduliferis. Pedicellus 3.5-5.5(-7) mm longus, glabratus praeter apicem. Sepala omnia biglandulifera, glandulas 1.2-2 mm longas 0.7-1.2 mm superantia, 1.2-1.5 mm lata, obtusa, appressa, abaxialiter sericea vel subglabrata, adaxialiter glabra. Petala lutea, glabra vel abaxialiter sparsissime sericea, integra vel minute denticulata, 4 lateralia patentia, ungue 0.7-1 mm longo, limbo 3.5-5 mm longo, 2.5-4 mm lato, obovato; petalum posticum erectum, ungue 1-1.4 mm longo, crasso, limbo 3.5-5.5 mm longo, 2.5-4 mm lato, obovato. Filamenta 1.1-1.8 mm longa, basi connata, sericea vel subglabra; antherae 0.9-1.1(-1.5) mm longae, glabrae vel basi paucipiliferae, connectivo atrorubro. Ovarium ca 1 mm altum, ± sericeum; styh 1.4-1.9 mm longi, aequales vel anticus paulo brevior, recti, glabri, apice interne stigmatifero dorsaliter rotundato, truncato, vel brevissime uncinato. Samara sericea vel glabrata; alae laterales 1.5-3(-5) mm longae (e nuce ad marginem), in 4 divisae vel, saepius, irregulariter lobatae, in eadem planta valde variabiles; ala dorsahs 0.5-1(-1.5) mm lata, integra vel sinuata; nux inter alas laterales et alam dorsalem saepe rugosa vel aliquot aculeis munita.
Distribution and Ecology - Distribution. Savannas of Amazonas, Venezuela, and Vaupes, Colombia.
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Discussion
Type. Maguire, Wurdack & Keith 41514, Yapacana savannas, NW base of Cerro Yapacana, Alto Río Orinoco, Amazonas, Venezuela, 16 Sep 1957 flr/imm frt (holotype MICH, isotypes NY, US, VEN). This species is named for its slender, wiry stems, producing the habit of a small shrub. It is obviously derived from Tetrapterys styloptera, but seems to be adequately distinguished from that species by its habitat, habit, small flowers, and small irregular samaras. One collection, Maguire et al 37571, shows some intermediacy in leaf-size to T. styloptera. It would be interesting to study these two species in areas where their habitats abut to look for more intermediates.