(2787) Proposal to conserve the name <i>Graffenrieda</i> against <i>Centronia</i> (<i>Melastomataceae</i>: <i>Merianieae</i>)
Bibliographic record
Abstract
(2787) Graffenrieda DC., Prodr. 3: 105. Mar (med.) 1828 [Melastomat.], nom. cons. prop. Typus: G. rotundifolia (Bonpl.) DC. (Rhexia rotundifolia Bonpl.). (=) Centronia D. Don in Mem. Wern. Nat. Hist. Soc. 4: 284, 314. 1823 (post 17 Mai), nom. rej. prop. Typus: C. laurifolia D. Don. Phylogenetic analyses of the tribe Merianieae (Melastomataceae) have shown that the type of Centronia D. Don is resolved within Graffenrieda DC., which is otherwise resolved as monophyletic (Dellinger & al. in New Phytol. 221: 1136–1149. 2018, in Commun. Biol. 2: 453. 2019; Caetano & al. in Perspect. Pl. Ecol. Evol. Syst. 46: 125556. 2020; Reginato & al. in Molec. Phylogen. Evol. 148: 106815. 2020). Centronia has long been considered a genus with problematic delimitations, especially when compared with Graffenrieda and Meriania Sw. (Wurdack in Lasser, Fl. Venezuela 8: 226. 1973, in Phytologia 35: 1–13. 1976; Almeda in Proc. Calif. Acad. Sci., ser. 4, 48: 141–152. 1993; Mendoza & Fernández in Anales Jard. Bot. Madrid. 69: 259–294. 2012). To date, 21 species names have been validly published in Centronia. However, only five, including the type, C. laurifolia D. Don, are currently accepted in the genus as the remaining have been transferred to Meriania (Wurdack, l.c. 1976, in Brittonia 39: 159–164. 1987; Almeda, l.c. 1993; Mendoza & Fernández, l.c.) or synonymized under Meriania or Wurdastom B. Walln. (Melastomataceae: Cyphostyleae) (Mendoza & Fernández, l.c.; Mendoza in Acta Bot. Mex. 127: e1642. 2020). The five species currently recognized in Centronia are distributed in the Andes from Colombia to Peru, or the Guayana Shield in Venezuela, Colombia, and Brazil, with all of them having been rarely collected from very restricted populations (Don in Mem. Wern. Nat. Hist. Soc. 4: 314–315. 1822; Triana in Trans. Linn. Soc. London 28: 71–72. 1873; Macbride in Publ. Field Mus. Nat. Hist., Bot. Ser. 13: 326–328. 1941; Wurdack in Bot. Mus. Leafl. 18: 160–166. 1958, in Mem. New York Bot. Gard. 10: 135–186. 1964, l.c. 1973; Berry & al., Fl. Venez. Guayana 6: 263–528. 2001; Baumgratz & al., Catal. Pl. Fung. Brasil 2: 1236–1278. 2010; Almeda & al., Catal. Pl. Líquen. Colombia: 1585–1664. 2016). Graffenrieda, on the other hand, includes ca. 70 recognized species from 88 validly published species and infraspecies names, and it has a wider distribution (and often more numerous herbarium collections) from southern Mexico and the Antilles to Bolivia and Brazil (Almeda in Davidse & al., Fl. Mesoamer. 4: 164–337. 2009; Goldenberg & Meirelles in Syst. Bot. 36: 119–123. 2011; Michelangeli & Goldenberg in Brittonia 66: 170–173. 2013; Michelangeli & Ulloa in Phytotaxa 77: 43–48. 2013; Almeda & al. in Phytotaxa 163: 39–47. 2014; Lima & al. in Kew Bull. 72: 47. 2017; Murillo & al. in Phytotaxa 391: 131–137. 2019). Centronia is distinguished from other genera in the Merianieae by the combination of large flowers, calyptrate calyx, and anthers with a dorsal connective appendage (Wurdack, l.c. 1973). The presence of a second dorsal connective appendage has also been associated with species of Centronia (Wurdack, l.c. 1973), but while this character is present in many of the species formerly treated in this genus, it is notoriously absent in the type and a few other species. Graffenrieda also has anthers with dorsal connective appendages and usually smaller flowers. While most species of Graffenrieda have a calyx opening by separate lobes, some species do have a calyptrate calyx, and many species with this character had been previously placed in Calyptrella Naudin, but they are all now treated in Graffenrieda (Williams in Fieldiana, Bot. 29: 562–564. 1963; Goldenberg & Meirelles, l.c.). Thus, based on both molecular data and morphological characters, there is no doubt of the position of Centronia laurifolia within Graffenrieda. Of the remaining four species in Centronia not yet included in molecular phylogenetic analyses, one (C. sessilifolia Cogn.) may be better placed in Meriania, while the other three have staminal characters consistent with Graffenrieda (Wurdack, l.c. 1976; Mendoza & Fernández, l.c.). Following nomenclatural priority, 70 species of Graffenrieda would require new combinations or new names in Centronia in order to achieve monophyletic genera. Because Graffenrieda is more widely distributed and many species are locally common, many tropical botanists and Melastomataceae specialists are familiar with this genus, while the knowledge and distribution of Centronia is more limited. Moreover, the concept of Centronia has probably been more closely associated with species now in Meriania, even if the type has characters that place it together with Graffenrieda. In summary, the conservation of Graffenrieda in favor of Centronia would significantly reduce the number of necessary new combinations or new names (from 70 to at most 4), and the number of specimens affected in herbaria. This action would be in line with other recent conservations in Melastomataceae aimed at preserving nomenclatural stability (e.g., Michelangeli & al. in Taxon 65: 892–893. 2016). JSM: https://orcid.org/0000-0003-4512-5811 FAM: https://orcid.org/0000-0001-7348-143X FA: https://orcid.org/0000-0002-4916-8897
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.005 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.005 | 0.005 |
| Insufficient payload (model declined to judge) | 0.007 | 0.008 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".