Myrtaceae
Creators: name: Amorim, Gabriela Dos Santos
name: Barbosa, Maria Regina De Vasconcellos
name: Jr, Eduardo Bezerra De Almeida
name: Thomas, William Wayt
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae

description: Myrtaceae   
Trees or shrubs, twigs glabrescent or densely pubescent, grayish or reddish. Leaves simple and opposite, margin entire, venation brochidodromous, stipules absent, glands present. Inflorescence axillary, terminal or subterminal, a solitary flower, panicles, thyrsoid, simple or auxotelic racemes, fascicles, glomerules, dichasium, cauliflorous; flowers radially symmetric, bisexual, dichlamydeous, sessile or pedicellate; bracts and bracteoles caducous or persistent; flowers bud constricted or not below ovary; calyx 4–5–merous, the lobes free, partially fused in the lower third of the bud or completely fused and opening by tearing or along the suture of a calyptra; corolla 4–5–merous, often ephemeral; stamens numerous. Fruit subglobose, globose, or ellipsoid, seeds few to numerous.  
Key to the species to Myrtaceae in forest fragments in Amazonian Maranhão  
1. Inflorescence a panicle or thyrsoid.....................................................................................................................................................2  
- Inflorescence a solitary flower, glomerule, fascicle, dichasium, or a simple or auxotelic raceme..................................................17  
2. Calyx-lobes free or partially fused in the lower third of the bud and 5-merous................................................................................3  
- Calyx-lobes completely fused, opening by tearing or as a calyptra.................................................................................................14  
3. Flower buds constricted above ovary and calyx reflexed..................................................................................................................4  
- Flower buds not constricted above and calyx not reflexed................................................................................................................5  
 4. Leaves with petioles unchanneled, leaf discolorous and flowers sessile................................................................ Myrcia tomentosa   
 - Leaves with petioles channeled, leaf concolorous and flowers pedicellate, 2.5–3.5 mm long....................................... Myrcia selloi   
 5. Midvein adaxially prominent; ovary 3-locular....................................................................................................... Myrcia guianensis   
- Midvein adaxially flat, impressed or sulcate; ovary 2-locular...........................................................................................................6  
 6. Leaf apex long-caudate; lateral veins prominent abaxially, arched....................................................................... Myrcia minutiflora   
- Leaf apex acute, acuminate, long acuminate, attenuate, rounded or obtuse, rarely cuspidate; lateral veins not prominent abaxially and not arched.....................................................................................................................................................................................7  
 7. Inflorescence a thyrsoid with congested flowers; aggregated in dichasia, the first branch ca. 1.5 cm above the base; bracteoles 7–8 × 3 mm...................................................................................................................................................................... Myrcia bracteata   
- Inflorescence a panicle with lax flowers, the first branch more than 1.5 cm above the base; bracteoles more or less 0.5–1.5 × 2 mm......................................................................................................................................................................................................8  
 8. Margin revolute; lateral veins strongly marked............................................................................................................. Myrcia eximia   
- Margin flat; lateral veins not marked.................................................................................................................................................9  
9. Leaf pubescent abaxially; fruits pubescent.......................................................................................................................................10  
- Leaf glabrous or glabrescent abaxially; fruits glabrous...................................................................................................................12  
 10. Flower bud campanulate; fruit globose........................................................................................................................ Myrcia cuprea   
- Flower bud globose; fruit oblong or ellipsoid..................................................................................................................................11  
 11. Leaf with petioles unchanneled and blades slightly discolorous, lustrous adaxially; midvein adaxially sulcate..... Myrcia sylvatica   
 - Leaf with channeled petiole and blades concolorous; midvein adaxially flat......................................................... Myrcia splendens   
 12. Leaf membranaceous, concolorous......................................................................................................................... Myrcia multiflora   
- Leaf chartaceous or coriaceous, discolorous....................................................................................................................................13  
 13. Branches reddish; panicle with the axis glabrous................................................................................................... Myrcia amazonica   
 - Branches grayish; panicle with the axis pubescent, the indumentum whitish............................................................ Myrcia grandis   
 14. Leaf membranaceous; panicle with axis 0.5-0.7 mm............................................................................................. Myrcia fasciculata   
- Leaves chartaceous or coriaceous; panicle with the axis more than 2.3 cm long............................................................................15  
 15. Twigs pubescent, with indumentum ochraceous; intramarginal vein 1-3 mm from the margin....................... Myrcia neoclusiifolia   
- Twigs glabrous; intramarginal vein 1 mm or less from the margin..................................................................................................16  
 16. Leaf with margin revolute; panicle and fruit pubescent....................................................................................... Myrcia neospeciosa   
 - Leaf with margin flat; panicle and fruit glabrous........................................................................................................... Myrcia pullei   
17. Calyx 4-merous; ovary 2-3-locular..................................................................................................................................................18  
- Calyx 4-5-merous; ovary plurilocular..............................................................................................................................................34  
18. Pedicels more than 1 mm long; calyx-lobes persistent in the fruit...................................................................................................19  
- Pedicels absent; calyx-lobes caducous in the fruit together with the petals and hypanthium as a unit............................................33  
19. Flowers arranged in fascicles, sometimes only two flowers per axis...............................................................................................20  
- Flowers arranged in racemes............................................................................................................................................................26  
 20. Leaves membranaceous...................................................................................................................................... Eugenia lambertiana   
- Leaves chartaceous or coriaceous....................................................................................................................................................21  
 21. Inflorescence cauliflorous..................................................................................................................................... Eugenia flavescens   
- Inflorescence axillary.......................................................................................................................................................................22  
 22. Calyx lobes deltate, pubescent adaxially and glabrous abaxially............................................................. Eugenia wullschlaegeliana   
- Calyx lobes obovate, orbicular or oblong, glabrous or sparsely pubescent.....................................................................................23  
 23. Midvein adaxially sulcate......................................................................................................................................... Eugenia protenta   
- Midvein adaxially impressed, prominent or flat...............................................................................................................................24  
 24. Leaf discolorous; the margin revolute.................................................................................................................. Eugenia dittocrepis   
- Leaf concolorous; the margin flat.....................................................................................................................................................25  
 25. Twigs pubescent; bracts lanceolate and bracteoles orbicular............................................................................... Eugenia punicifolia   
 - Twigs glabrous; bracts orbicular and bracteoles elliptic or oblong..................................................................... Eugenia stictopetala   
 26. Raceme auxotelic with cataphylls at the base............................................................................................................ Eugenia patrisii   
- Raceme simple..................................................................................................................................................................................27  
 27. Lateral veins arched; inflorescence glabrescent......................................................................................................... Eugenia florida   
- Lateral veins not arched; inflorescence pubescent...........................................................................................................................28  
28. Twigs glabrous; bracts caducous before anthesis.............................................................................................................................29  
- Twigs densely or sparsely pubescent; bracts caducous after anthesis..............................................................................................30  
 29. Intra-marginal vein 4–6 mm from the margin; midvein sulcate; fruit oblong to ellipsoid.......................... Eugenia caducibracteata   
 - Intra-marginal vein 1–3 mm or less from the margin; midvein flat; fruit globose.................................................. Eugenia cupulata   
 30. Calyx-lobes partially fused in the lower third of the bud; fruit glabrous...................................................... Eugenia densiracemosa   
- Calyx-lobes free; fruit pubescent......................................................................................................................................................31  
 31. Leaves concolorous; leaf margin revolute.................................................................................................................. Eugenia biflora   
- Leaves discolorous; leaf margin flat.................................................................................................................................................32  
 32. Bracts caducous after anthesis; fruit with muricate surface....................................................................................... Eugenia patens   
 - Bracts persisting in the fruit; fruit with smooth surface..................................................................................... Eugenia polystachya   
 33. Leaves 4.4–7.3 × 2.8–3 cm, apex leaf acuminate............................................................................................... Myrciaria floribunda   
 - Leaves 1–2.5 × 0.5–1.2 cm, apex leaf acute............................................................................................................. Myrciaria tenella   
 34. Intra-marginal vein 1–2 mm from the margin; bracts and bracteoles persistent in the fruit.......................... Calycolpus goetheanus   
- Intra-marginal vein absent; bracts and bracteoles caducous after anthesis......................................................................................35  
 35. Calyx-lobes partially fused in the lower third of the bud; fruit with smooth surface............................... Campomanesia aromatica   
- Calyx-lobes completely fused, opening by irregular tearing; fruit with surface marked with glands.............................................36  
 36. Leaf apex always apiculate; midvein adaxially sulcate; flower buds globose.................................................. Psidium acutangulum   
 - Leaf apex never apiculate; midvein adaxially impressed; flower buds pyriform.................................................. Psidium guineense
description: Published as part of Amorim, Gabriela Dos Santos, Barbosa, Maria Regina De Vasconcellos, Jr, Eduardo Bezerra De Almeida & Thomas, William Wayt, 2022, Taxonomic study of Myrtaceae in forest fragments in Amazonian Maranhão, Brazil, pp. 27-60 in Phytotaxa 568 (1) on pages 29-31, DOI: 10.11646/phytotaxa.568.1.3, http://zenodo.org/record/7184245