Mapouria

Taylor, Charlotte M., 2020, Overview of Psychotria in Madagascar (Rubiaceae, Psychotrieae), and of Bremekamp’s foundational study of this group, Candollea 75 (1), pp. 51-70 : 56-58

Mapouria

Morphology and identity of Bremekamp’s Malagasy Mapouria BREMEKAMP (1963) recognized 66 species of Mapouria from Madagascar and one from the Comores based on diagnostic pyrene and endosperm characteristics, but these plants are widely variable in their other morphological features. Even apart from new insights we have now from molecular analysis, his separation of Mapouria here was problematic because his pyrene and endosperm characters vary widely in Psychotria , and his use of the name Mapouria for this group was based on an inaccurate interpretation of the name Psychotria .

BREMEKAMP (1934, 1961, 1963) diagnosed Mapouria and separated it from Psychotria by pyrenes that are flat adaxially (i.e., plane, without a groove or ridge), endosperm that is sparsely to densely ruminated but lacks the distinctive T-shaped intrusion of Apomuria , stipules that are deciduous, and distylous flowers. He circumscribed Mapouria to include also the Paleotropical genus Grumilea Gaertn. ( BREMEKAMP, 1961) . However, the ruminated endosperm that BREMEKAMP (1963) used to diagnose Mapouria has been demonstrated ( PETIT, 1964; PIESSCHAERT, 2001; SOHMER & DAVIS, 2007) to be extensively variable even among closely related species in Psychotria , so this feature does not diagnose systematic groups. The form of the adaxial pyrene face has been also demonstrated to vary widely in Psychotria ( PETIT, 1964; PIESSCHAERT, 2001), as discussed in the previous section. And, most species of Psychotria have deciduous stipules and distylous flowers. This leaves Bremekamp’s Mapouria diagnosed only by a combination of several variable features. PETIT (1964: 24) tested the morphological characterization of Bremekamp’s new group and concluded that it could not be separated from or within African Psychotria . PETIT (1964) formally synonymized Grumilea with Psychotria , and informally commented that Mapouria in Bremekamp’s classfication also could not be separated.

Mapouria was included in Psychotria in the Neotropics by most authors starting in the early 20th century (e.g., STANDLEY, 1930; STEYERMARK, 1972), but it was still recognized there by BREMEKAMP (1934) and then extended by him to Madagascar ( BREMEKAMP, 1961, 1963). DAVIS et al. (2007) reviewed the morphological characters and available molecular studies of Bremekamp’s Paleotropical Mapouria , and concluded again that it was not distinguishable from Psychotria . They formally transferred Bremekamp’s species to Psychotria with the necessary new nomenclatural combinations ( DAVIS et al., 2007; DAVIS & GOVAERTS, 2008), but did not study this group taxonomically or comment on the nomenclatural aspects of Bremekamp’s use of that name.

Mapouria was the largest genus BREMEKAMP (1963) recognized in the Malagasy Psychotria , and as a group its species are generally recognizable by the combination of their deciduous stipules, ruminate endosperm, and lack of the features that characterize most of the other genera. Mapouria in Madagascar has sometimes been characterized informally by its bright yellow corollas with relatively long tubes and its red fruits, but Bremekamp also included here species with white corollas and blue or white fruits. Bremekamp recognized seven informal species groups of Mapouria based on morphological features such as corolla color, inflorescence position, rumination pattern of the endosperm, and the presence of acarodomatia on the leaves. He designated these species groups only with numbers, and called them “Groups” in his key but “Series” in the taxonomic treatment.

Bremekamp’s Malagasy Mapouria analyzed with molecular data ANDERSSON (2002) included the type of Mapouria , from the Neotropics, and two Malagasy species in his analysis, and studied two of Bremekamp’s diagnostic characters, endosperm rumination and stipule persistence. He found Mapouria ’s type nested in his Psychotria Clade I and synonymized this name. He found one of his Malagasy Mapouria species placed in his Clade III, and the other was placed by itself within his Psychotria s.str. Andersson also found the presence and pattern of endosperm rumination and stipule persistence to be widely homoplasious across his analysis of Psychotria . RAZAFIMANDIMBISON et al. (2014) studied nine species of Bremekamp’s Mapouria , and found them all separated from each other on well supported clades, and all grouped with species that Bremekamp classified in Psychotria . None of the Malagasy species of Bremekamp’s Mapouria were found to be closely related to the type of Mapouria by either Andersson or Razafimandimbison et al., nor to the type of Grumilea by Razafimandimbison et al. The extensive morphological heterogeneity of Bremekamp’s Mapouria is mirrored by the extensive polyphyly found in this group by molecular analysis ( RAZAFIMANDIMBISON et al., 2014). In the results of Razafimandimbison et al., some of Bremekamp’s Malagasy Psychotria species groups are paraphyletic and the others were not sampled adequately and can’t be evaluated.

The name Mapouria as used by Bremekamp

Separation of Bremekamp’s segregate genera from Psychotria required him to determine appropriate names for them, and their names depended on the identity of Psychotria . Bremekamp’s analysis of Psychotria ’s identity was idiosyncratic, and as result so was the name he used for his largest segregate genus. Psychotria was described with one species, P. asiatica L., that was based on one paleotropical element from Asia and one neotropical element from the Antilles ( BREMEKAMP, 1961; PETIT, 1964; DAVIS et al., 2001). Because there were two elements, BREMEKAMP (1961: 317) concluded that Psychotria was a “ nomen confusum ” whose identity could not be determined. Bremekamp diagnosed his newly separated genera in part by stipule persistence, and he concluded that Psychotria as of P. biloba (Bremek.) Razafim. & B. Bremer ; C. Unusually large green fruits of P. tolongoinensis A.P. Davis & Govaerts ; D. Dense pubescence of P. rufovillosa (Bremek.) A.P. Davis & Govaerts ; E. Blue fruits of P. glaucifolia A.P. Davis & Govaerts ; F. White fruits of P. decaryi Bremek. [A: Syde et al. 291; B: Bolliger 123; C: Razafindrahaja 242; D: Antilahimena 8184; E: Callmander 393; F: Rasoanindriana et al. 148]

[Photos: A, C, D, F: P. Antilahimena; B: R. Bolliger; E: M. Callmander]

originally described probably had persistent stipules. He did not see any original material that corresponded to P. asiatica , but based his conclusion only on later use of that name by some other authors. Based on this, he then decided that P. asiatica did not agree with the genus he diagnosed by having deciduous stipules, so another name was needed for that newly separated genus. He then concluded that Mapouria was the oldest name in this group that demonstrably had deciduous stipules, and that Grumilea shared this feature and was not distinct from Mapouria . BREMEKAMP (1961) then used the name Mapouria for his newly separated Malagasy genus, and noted that using this name for this group was due to a possible major change in nomenclatural usage of the name Psychotria . He explained that if the type of Psychotria was eventually studied and confirmed to have persistent stipules, most of the species across the world with names in Psychotria should instead be called Mapouria . Bremekamp then recommended that in this case, for nomenclatural convenience, a different type should be chosen for Psychotria , and it should agree with his Mapouria so these numerous name changes would not be needed (he did not comment on how to resolve the nomenclature of the species with persistent stipules that he placed in Psychotria ). Bremekamp’s views here were contrary to our current nomenclatural practice ( TURLAND et al., 2018), so his conclusions conflict with today’s nomenclature and have created lasting confusion. Current nomenclatural practice prefers to find the identity of a name by direct study of original material, to confirm this identity before the name is used or a substitute name adopted, and to propose formal conservation of names that are problematic instead of just mentioning a possible problem.

The identity of Psychotria was also reviewed contemporaneously but separately by PETIT (1964), who did study the original material of Psychotria . He concluded that its two type elements are morphologically consistent and the Asian material should be considered the type of P. asiatica . He confirmed that both of the original elements have deciduous stipules, so Bremekamp’s interpretation of this name was inaccurate. DAVIS et al. (2001) then reviewed the identity of P. asiatica in more detail, and formally accepted PETIT (1964) ’s conclusion as a lectotypification (the problem that Bremekamp noted with the characteristics of Psychotria has since been resolved by separating many of the heterogeneous Psychotria species into other genera and even tribes, e.g., ANDERSSON, 2001; RAZAFIMANDIMBISON et al., 2014).