Monographs Details: Mouriri ambiconvexa Morley
Authority: Morley, Thomas. 1976. Melastomataceae tribe Memecyleae. Fl. Neotrop. Monogr. 15: 1-295. (Published by NYBG Press)
Description:Description - The epithet refers to the midrib of the leaf, which is prominently rounded both aboye and below. Midrib xylem tubular; stomatal crypts Type I, the roof arched; upper epidermis one cell thick, mucilaginous walls often present, 1/5-1/4 the depth of the cell; hypodermis none; free stone cells present only near base of petiole; central bodies of terminal sclereids 1-2 times as long as wide, with several sharp arms of medium length, strong vertical bodies often present.

Latin Diagnosis - Plantae lignosae 3 m altae, habitu ignoto, praeter inflorescentiam glabrae; ramuli juvenes 4-alati. Petioli 1.0-3.0 mm longi; laminae 6.8-13.2 cm longae, 2.9-4.0 cm latae, anguste ovato-ellipticae vel ovato-oblongae, apice abrupte acuminato, acumine 8.0-14.0 mm longo, basi acuta ángulo incluso 80-95°; paginae superiores et inferiores costae mediae rotundatae prominentes; nervi laterales conspicui in sicco. Cryptae stomatatae 35-60 µ diametris, ca. 22 µ altae, ca 14 in mm2; sclerides terminales foliariae stellatae. Inflorescentiae cauliflorae et in ramis usque 10.0 mm diametro, non axillares, l-8 simul, saepe congesti, singulae l(-3?)-florae, 1.8-2.8 mm longae cum internodiis 1-2 ad bases pedicellorum, interdum ramosae; bracteae 0.5-1.2 mm longae, triangulares vel ovato-triangulares et abrupte breviacuminatae; pedicelli 1.3-2.0 mm longi. Bracteae et pedicelli minute puberuli. Calyx ovarium inferior includens 5.0-6.5 mm longus; hypanthium liberum 3.6 mm longum; lobi calycis in alabastro 1.0-1.3 mm longi, 1.6-1.7 mm lati, in fructu 1.0-1.4 mm longi, 2.3-3.1 mm lati, triangulares vel rotundato-triangulares, acuti, 3.5-4.0 mm longi ab staminibus; calyx 1.2-1.6 mm findens inter lobos sub anthesi. Petala matura ignota. Antherae 4.0-4.2 mm longae; thecae 3.9-4.1 mm longae; glandula 0.3-0.4 mm longa cum centro 2.8-3.1 mm ab apice antherae. Ovarium 4-loculare, placentatione axiali-basilari; ovula 3-4 in quoque loculo. Fructus luteus, depresso-globosus, hypanthio et aliquot lobis calycis coronatus, ca. 13.0-14.5 mm altus calyce excluso, 14.0-17.5 mm diametro, 1-spermus. Semen fuscum pro parte maxima, brunneum ad basim, 8.5-9.0 mm longum, 7.2-7.7 mm latum, 6.2-6.5 mm crassum, strato tenui albido ex ovario oriundo obtectum; hilum rotundum, basale, ca. 3.8 mm diametro.

Discussion:The primary distinguishing features of this species are the midrib, which is prominently rounded above as well as below, the low frequency and arched roof of the stomatal crypts, the cauliflorous and ramiflorous flowers, the short peduncles and moderately long anthers, and the single seed with its thin clinging whitish layer of ovary tissue. No other species appears close enough to be confused with this one. Perhaps M. grandiflora is the most similar. From the latter M. ambiconvexa is distinguished by the midrib and stomatal crypt characters cited, by its smaller flowers, and by the single seed with its whitish layer.
Distribution:Colombia South America| Amazonas Colombia South America| Vaup├ęs Colombia South America|