Arachnothryx venezuelensis Steyerm.

• Authority

  Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.

• Family

  Rubiaceae

• Scientific Name

  Arachnothryx venezuelensis Steyerm.

• Description

  Latin Diagnosis - Frutex 1 m, ramis novellis arachnoideis; stipulis oblongo-ligulatis obtusis 12-13 mm longis extus basi infra mediumque arachnoideis supra medium glabris vel glabratis; foliis petiolatis, petiolis 11-13 mm longis arachnoideis vel per mar-gines superiores villosioribus; laminis late elliptico-ovatis apice acutis vel acuminatis basi subacutis 11-17.5 cm longis 4.5-9.5 cm latis supra glabris praeter costam median cano-arachnoideam, subtus costa media nervis lateralibusque arachnoideis vel fere glabratis venulis tertiariis paullo remote arachnoideis aliter glabris, utrinque rugulosis, supra nervis sulcatis, nervis lateralibus utroque latere 11-15; venulis tertiariis conspicue rugulosis inter nervos laterales transverse areolatis subtus praesertim; inflorescentiis trichotome ramosis 5.5-6 cm longis 6-9 cm latis, pedunculo elongato 9.5-13 cm longo arachnoideo; bracteis linearibus vel subulatis acutis 11-15 mm longis 1.5-1.7 mm latis subglabratis plerumque 3-nervatis; florium bracteis subulatis vel linearibus acutis 5 mm longis 1 mm latis extus floccoso-arachnoideis; calyce hypanthioque 10-11 mm longo; hypanthio anguste oblongo-turbinato vel subcylindrieo-turbinato 3.5-4 mm longo 1.5 mm lato extus dense arachnoideo; calycis tubo supra discum 0.5 mm longo intus glabro, lobis 4 lanceolatis acutis 5.5-7 mm longis 1.1-1.5 mm latis distincte 5-nervatis extus arachnoideis intus glabris, inter lobos glandulis duobus in sinu interpositis; corolla 18 mm longa, tubo 14 mm longo basi 1.8 mm lato apice 3.5 mm lato extus dense arachnoideo intus parte basilari 4.5 mm pubescenti deinde glabro ad faucem, lobis 4 suborbicularibus crenulatis 3.5 mm longis 4 mm latis extus basi dense arachnoideis intus papillatis; staminibus ad 3/8 -1/2 longi-tudinem tubi affixis, antheris linearibus 3.5 mm longis, filamentis 0.8 mm longis; stylo 12 mm longo glabro; stigmate 2.5 mm longo.

• Discussion

  This species differs from Rondeletia rugulosa Standley of Colombia in the much longer, more foliaceous calyx-lobes, longer corolla-tube, arachnoid lower leaf-surface, larger leaf-blades, longer petioles, and densely arachnoid pubescence of the hypanthium, stems, and corolla-tube.