Octopleura Grisebach 1860
Creators: name: Gamba, Diana
name: Almeda, Frank
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Melastomataceae
Octopleura

description: Key to the Species of the Octopleura Clade  1.  
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 Inflorescences a sessile cluster of fasciculate glomerules or a fascicle-like cluster of cymes with poorly developed branching; calyx lobes reflexed; seeds mostly> 0.5 mm long, pyramidal with a rugose testa............................................. 2. Inflorescences a group of modified dichasia, a thyrsoid or a dithyrsoid, with moderate to highly developed branching; calyx lobes erect to spreading but not reflexed; seeds generally <0.5 mm long, ovoid or ovoid-angled with a smooth testa (except for M. incerta which has a rugose testa)................................................................................................................. 10. 2.   
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 Indumentum on uppermost internodes and hypanthia composed of somewhat flattened elongate slightly to moderately roughened trichomes (absent in some populations of M. approximata); inflorescences a sessile cluster of fasciculate glomerules with no developed branching.............................................................................................................................. 3. Indumentum on uppermost internodes and hypanthia composed of clavate dendritic trichomes with short to elongate thinwalled arms (if the indumentum consists of elongate-roughened trichomes then the inflorescences not a fasciculate cluster); inflorescences a fascicle-like cluster of cymes with poorly developed branching.................................................. 7. 3.   
 - The elongate slightly to moderately roughened trichomes on uppermost internodes and hypanthia 1.5 to 3 mm long...... 4. The elongate slightly roughened trichomes on uppermost internodes and hypanthia less than 1.5 mm long (absent in some populations of M. approximata)............................................................................................................................................ 5. 4.   
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 Lanate indumentum white; leaves 5-nerved; flowers 5-merous; torus adaxially glabrous to somewhat scaly; ovaries 5- locular ................................................................................................................................................................. M. chocoensis Lanate indumentum ferruginous; leaves 5─7-plinerved; flowers 4-merous; torus covered adaxially with short-stalked glands; ovaries 4-locular ............................................................................................................................... M. quadridomius 5.   
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 Leaves apex bluntly apiculate, 5─7-plinerved, the foliar veins thick and succulent; berries 6.59–7.34 × 4.31–5.3 mm when dry, globose-elliptic to globose-obovate ........................................................................................................... M. veraguensis Leaves apex gradually acuminate to long-acuminate, 5-nerved, the foliar veins thin and not succulent; berries 2–2.5 × 5–6 mm when dry, globose-oblate................................................................................................................................................ 6. 6.   
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 Hypanthium at anthesis 2.4–2.5 × 1.4–1.5(–2.2) mm; anthers 1.4–1.5 × 0.25–0.33 mm, linear-oblong; flowers 4-merous.. ......................................................................................................................................................................... M. approximata Hypanthium at anthesis 2.8–3 × 1.5–1.7 mm; anthers 1.9–2 × 0.4–0.5 mm, oblong-obovate; flowers 5-merous.................. ....................................................................................................................................................................... M. anchicayensis 7.   
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Petals triangular-subulate or narrowly lanceolate, the apex bluntly acute to acuminate; berries purple or purple black at maturity................................................................................................................................................................................. 8. Petals ovate-oblong or obovate-oblong, the apex bluntly and widely acute to obtuse-rounded; berries bright orange or reddish at maturity................................................................................................................................................................. 9. 8.  
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 Indumentum on uppermost internodes pulverulent-furfuraceous with dendritic trichomes <0.1 mm long with short to moderately long flattened arms; indumentum on hypanthia consisting of white and resinous furrowed sessile glands; the deflexed dorso-basal connective appendage 0.25–0.5 mm long, lanceolate .............................................. M. alboglandulosa Indumentum on uppermost internodes granulose-asperous with dendritic trichomes 0.15–2 mm long with moderately long flattened arms, occasionally intermixed with, or completely replaced by elongate slightly roughened trichomes 0.6–1 mm long; indumentum on hypanthia consisting of dendritic trichomes and resinous slightly furrowed more or less stalked glands; the deflexed dorso-basal connective appendage 1.2 mm long, linear-lanceolate ........................................ M. renatoi 9.   
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 Petioles 0.3–1.5 cm long; blade base attenuate to acute; tertiary and higher order leaf veins abaxially copiously beset with white furrowed sessile glands; inflorescences 0.25–1.15 cm long; hypanthia 2–2.5 mm long ......................... M. aurantiaca Petioles 1.5–4.7 cm long; blade base obtuse to rounded; tertiary and higher order veins abaxially copiously beset with sessile to short-stalked glands with thin-walled heads; inflorescences 1–2.5(4.7) cm long; hypanthia 3.1–3.5 mm long...... ........................................................................................................................................................................... M. evanescens   
 10. Indumentum on uppermost internodes, inflorescence axes, and hypanthia completely glandular; upper cauline internodes strongly quadrate and winged .............................................................................................................................. M. alatissima   
 34 Phytotaxa 179 (1) © 2014 Magnolia Press   
GAMBA & ALMEDA  
- Indumentum on uppermost internodes, inflorescence axes, and hypanthia with different types of eglandular and glandular trichomes or if with only one type of trichome then uniformly stellate, lepidote, or dendritic but never glandular; upper cauline internodes terete or shallowly quadrate and not winged..........................................................................................11.  
11. Leaves markedly to more or less anisophyllous in each pair, petiolate; indumentum on uppermost internodes asperous with dendritic trichomes or arachnoid with sessile-stellate trichomes; petals rounded to rounded-truncate at the apex, densely papillose on both surfaces; seeds with the raphal zone notably expanded ventrally and longitudinally............................ 12.  
- Leaves essentially isophyllous in each pair, petiolate or subsessile (if subsessile then the indumentum on uppermost internodes asperous with dendritic trichomes); indumentum on uppermost internodes puberulent-dendritic, mealyfurfuraceous, squamate, thickened-claviform, tomentose, or hispid; petals bluntly acute to acuminate at the apex, glabrous with trichomes only on the abaxial surface, or with trichomes on both surfaces but with different trichome types on each surface; seeds with the raphal zone only moderately expanded ventrally at one side (micropylar or chalazal)................. 19.  
12. Leaves of each pair markedly anisophyllous in size and shape, with a thick-callose vesicular structure at the abaxial blade base where the innermost pair of secondary veins diverge from the primary vein; leaf margins eciliate; indumentum on primary and secondary abaxial foliar veins appearing arachnoid with sessile-stellate trichomes...................................... 13.  
 - Leaves of each pair slightly anisophyllous only in size, lacking callose vesicular structures at the abaxial blade base where the innermost pair of secondary veins diverge from the primary vein; leaf margins ciliate (except for some individuals of M. atropurpurea); indumentum on primary and secondary abaxial foliar veins asperous with dendritic trichomes that have a short axis and few-moderate number of terete arms......................................................................................................... 15.   
 13. Larger leaf at each node elliptic-oblong and falcate, 3–5-nerved ......................................................................... M. radicans   
- Larger leaf at each node broadly ovate to subrotund, or oval-orbicular, 5–7-nerved......................................................... 14.  
 14. Hypanthia 2.8–2.9 mm long at anthesis, cylindric to campanulate and not constricted distally, resinous-glandular with slightly furrowed more or less stalked glands; calyx teeth to 0.2 mm long and not projecting beyond the calyx lobes......... ........................................................................................................................................................................ M. erikasplundii   
 - Hypanthia 3.2–3.4 mm long at anthesis, urceolate and constricted distally into a subcylindric neck, arachnoid with appressed matted sessile-stellate trichomes; calyx teeth 0.7–0.8 mm long and projecting beyond the calyx lobes................ ............................................................................................................................................................................ M. biolleyana   
 15. Hypanthium at anthesis beset with asperous dendritic trichomes, densely intermixed with elongate smooth trichomes but lacking glands of any kind .............................................................................................................................. M. atropurpurea   
- Hypanthium at anthesis copiously beset with resinous slightly furrowed more or less stalked glands intermixed with asperous dendritic and/or elongate smooth trichomes in variable quantities...................................................................... 16.  
16. Blade base attenuate to oblique, conspicuously and narrowly decurrent on the petiole; torus copiously resinous-glandular adaxially............................................................................................................................................................................. 17.  
- Blade base rounded to obtuse, not decurrent on the petiole; torus moderately to densely ciliate adaxially....................... 18.  
 17. Inflorescence axes greenish; flowers 4-merous; hypanthium green-whitish; ovary 4-locular; berries bright-orange at maturity ................................................................................................................................................................. M. aguilarii   
 - I nflorescence axes pinkish; flowers 5-merous; hypanthium yellowish becoming bright pink; ovary 5-locular; berries purple-black at maturity ............................................................................................................................... M. quinquenervia   
 18. Adaxial foliar surface sparsely to moderately strigose with pinkish subulate-smooth trichomes; hypanthium densely setose with pinkish subulate-smooth trichomes; exterior teeth ca. 1 mm long including the apical trichome, bluntly conic and 1–3-aristate ............................................................................................................................................................ M. reitziana   
 - Adaxial foliar surface glabrate; hypanthium not setose with only slightly furrowed more or less stalked glands; exterior teeth ca. 0.5 mm long, subulate and lacking aristae ........................................................................................ M. neocoronata   
19. Leaves subsessile, the blade base cordate-amplexicaul, not decurrent on the petiole........................................................ 20.  
- Leaves petiolate or subsessile, if subsessile the blade base decurrent on the petiole, if the base cordate then not amplexicaul and the leaves petiolate................................................................................................................................... 22.  
 20. Leaves ovate-lanceolate; hypanthium at anthesis copiously resinous with slightly furrowed more or less stalked glands, the torus glabrous adaxially; exterior calyx teeth 1.3–1.5 mm long, linear-subulate and projecting beyond the calyx lobes....... .................................................................................................................................................................................. M. incerta   
- Leaves elliptic to oblong-elliptic; hypanthium not resinous-glandular, the torus copiously resinous-puberulent with slightly furrowed more or less stalked glands adaxially; exterior calyx teeth 0.2–0.5 mm, bluntly triangular and not projecting beyond the calyx lobes........................................................................................................................................................ 21.
description: Published as part of Gamba, Diana & Almeda, Frank, 2014, Systematics of the Octopleura Clade of Miconia (Melastomataceae: Miconieae) in Tropical America, pp. 1-174 in Phytotaxa 179 (1) on pages 34-35, DOI: 10.11646/phytotaxa.179.1.1, http://zenodo.org/record/10089927