Tibouchina dissitiflora Wurdack

• Authority

  Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.

• Family

  Melastomataceae

• Scientific Name

  Tibouchina dissitiflora Wurdack

• Description

  Latin Diagnosis - T. fraternae N. E. Br. affinis sed floribus maioribus solitariis, pubescentia foliorum subtus aliter; T. duidae Gl. et T. sipapoanae Gl. affinis sed foliis distincte trinerviis. Fruticosa; ramuli, petioli, folia subtus, hypanthium, sepalaque squamis plusminusve ciliolatis omnino obsiti. Petioli crassi 2-4 mm longi; lamina crasse coriacea 1-2.5 X 0.8-1.5 cm, elliptica vel suborbicularis, apice late acuta vel obtusa et plerumque breviter apiculata, basi acuta vel obtusa, trinervia vel indistinct 5-nervia (nervis lateralibus a marginibus 1-2 mm distantibus) nervis supra insculptis subtus elevatis, supra striolata et in lineis longitudinalibus distinctis elevatis inter nervos indistincte vel distincte squamulosa. Flores 5-meri in ramulis solitarii sessiles vel vix (ad 1 mm) pedicellati, bracteis 2-4 liberis investi, bracteis duabus extimis foliaceis et petiolatis vel bracteosis et sessilibus, 8-11 X 3-5 mm, extus squamosis intus striolatis vel apieem versus squamosis et basim versus glabris, duabus intimis sessilibus ovatis extus squamosis intus glabris. Hypanthium 6-6.5 X 5-6 mm.; calycis tubus 0.5 mm altus, lobis 7-11 3-3.5 mm, ovatis vel ovato-triangularibus apice acutis vel parce ac.uminatis intus glabris. Petala 12-19 X 8-17 mm, obovata oblique truncata vel rotundata breviter glanduloso-ciliolata. Stamina paulo dimorpha glabra, thecis apice attenuatis. Stamina maiora: filamenta 7-10.5 mm; thecae 6.5-7.5 mm, connectivo sub thecis 2-3 mm producto basi vix (ad 0.7 mm) hebetibilobulato. Stamina minora: filamenta 6-9.5 mm; thecae 6-7 mm, connectivo sub thecis 1.3-1.7 mm producto basi vix (ad 0.5 mm) hebetibilobulato! Stylus 12-16.5 X 0-7 mm glaber vel sparsissime squamulatus; ovarium 5-loculare in parte dimidiali apicali squamosum vel squamoso-setosum.

• Discussion

  T. fraterna (fig. 11p) has much smaller flowers in terminal panicles; the squamules of the lower leaf surface are much narrower, with the free ends not overlapping one another. T. sipapoana (Fig. 11s) has smaller one-nerved leaves. The Guanay and Yutaje collections of T. dissitiflora show relatively shorter less acuminate calyx-lobes, but subspecific separation from the Xeblina population does not seem justified at present.