Revision of the Neotropical Genera <I>Bocageopsis, Onychopetalum
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BLUMEA 52: 413–554 Published on 18 December 2007 http://dx.doi.org/10.3767/000651907X608909 REVISION OF THE NEOTROPICAL GENERA BOCAGEOPSIS, ONYCHOPETALUM, AND UNONOPSIS (ANNONACEAE) PAUL J.M. MAAS, LUBBERT Y.TH. WESTRA & MARLOES VERMEER Nationaal Herbarium Nederland, Utrecht University branch, W.C. van Unnikgebouw, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands SUMMARY A taxonomic revision is made of the Neotropical genera Bocageopsis, Onychopetalum, and Unonopsis (Annonaceae). The closeness of these three genera was expressed by Fries when he placed them in his (informal) Unonopsis group (Fries, 1959), and the close relationship is supported by more recent phylogenetic research as well. Four species are recognized in Bocageopsis and two species in Ony- chopetalum. Unonopsis is by far the largest of the three genera with close to 50 species, of which no less than 23 species are here described as new. One species (Unonopsis umbilicata) had to be shelved as insufficiently known for lack of data, and another, obviously new, species from Colombia is too incomplete and is described provisionally as Unonopsis spec. A. Several keys are provided, one for the genera and one each for the species of Bocageopsis and Onychopetalum. For the species of Unonopsis a key to all species and, in addition, a key to the spe- cies of Mexico and Central America are provided. The species treatments include full descriptions, geographical and ecological notes, distribution maps, synonymy, taxonomic notes, and vernacular names. A complete list of exsiccatae is appended. Parallel to the taxonomic revision, a leaf anatomical survey was made by E.-J. van Marle, and is included here. Key words: Annonaceae, Bocageopsis, Onychopetalum, Unonopsis, leaf anatomy, taxonomy. INTRODUCTION The Neotropical genus Unonopsis was first published by Robert E. Fries in 1900. The two allied genera Bocageopsis and Onychopetalum, also from the Neotropics, were published later (Fries, 1931). Some years thereafter a revision of all three genera fol- lowed (Fries, 1937). In the large survey of the whole family (Fries, 1959) the three genera were placed in the ‘Unonopsis-Gruppe’, an informal group including the three Neotropical genera along with five genera from Africa (Dennettia, Dielsiothamnus, Polyceratocarpus, Uvariastrum, and Uvariodendron) and one from Asia (Neouvaria). Diagnostic features of the Unonopsis group are axillary inflorescences, the presence of bracts, articulate pedicels, valvate sepals, petals in two trimerous whorls, valvate, the outer petals not entirely touching toward the base and leaving a part of the inner petals uncovered, the uncovered median part of the inner petals raised and covered by hairs, carpels with laterally attached ovules in varying number, fruit apocarpous, and monocarps most often shortly stipitate. © 2007 Nationaal Herbarium Nederland, Leiden University branch 414 BLUMEA — Vol. 52, No. 3, 2007 In his key Fries distinguished Bocageopsis and Onychopetalum from Unonopsis by a staminal character, Unonopsis having the connective prolonged into an apical, discoid shield, vs Bocageopsis and Onychopetalum having a tongue-like, long-acute connective shield. He differentiated Onychopetalum from Bocageopsis by the petals provided with an incurved apical appendage and the presence of 3 or 4 ovules per carpel. Bocageopsis lacks an incurved apical appendage on the petals and has only 2 ovules per carpel. In his 1937 revision of the genus Unonopsis, Fries distinguished 22 species, but by the time of his survey of the whole family (1959) the number had increased to 27 species. After 1959 the genus did not undergo any further revisional work, though a few more new species were added: Unonopsis storkii Standl. & L.O. Williams (Williams, 1963), U. aviceps Maas and U velutina Maas (Maas et al., 1986), U. macrocarpa Maas & Setten (Maas et al., 1988), and U. theobromifolia N. Zamora & Poveda (1988). The present monographic study of Unonopsis was started in 1999 by Camilla Orava, then an MSc student from Helsinki, Finland, working in Utrecht under the supervision of P.J.M. Maas. Due to private circumstances Ms. Orava had to abandon her monographic work in 2001, after which the task of revising the genus fell to Maas and Westra. In our revision of Unonopsis 47 species are recognized, 25 of which are new or of very recent date (see U. bauxitae Maas, Westra & Mello-Silva). Almost half of the 27 species distinguished by Fries in 1959 are now put into synonymy. This also applies to U. velutina just mentioned (currently synonymized with U. spectabilis Diels). Yet, as compared to Fries’s 1937 revision, the number of species in Unonopsis has more than doubled. In Bocageopsis Fries (1937, 1959) distinguished three species, all transferred from Bocagea. A fourth species, B. pleiosperma Maas, was described more recently (Maas et al., 1986). All four species are accepted in the present treatment. Onychopetalum initially was published with the sole species O. amazonicum R.E. Fr. In his 1937 paper Fries added three more species. Later on, Johnson & Murray (1995) transferred Trigynaea periquino Rusby to Onychopetalum, at the same time putting O. krukoffii R.E. Fr. into synonymy with O. periquino (Rusby) D.M. Johnson & N.A. Murray. In the present treatment only two species are recognized, namely: O. amazonicum R.E. Fr. (incl. O. lanceolatum R.E. Fr.) and O. periquino (now also including O. lucidum R.E. Fr.). Both Bocageopsis and Onychopetalum were revised by Marloes Vermeer, at that time a Utrecht undergraduate student, and the third author of the present paper. Various classificatory studies on the position of genera in the Annonaceae, using different characters, have been published. 1) Walker (1971), in his survey of pollen characters in Annonaceae, distinguished a Malmea subfamily and within that the Malmea tribe. In that tribe he included 10 Neotropical genera, viz. Bocageopsis, Cremastosperma, Ephedranthus, Malmea s.l., Onychopetalum, Oxandra, Pseudephedranthus, Pseudoxandra, Ruizoden- dron, and Unonopsis, and the African genus Annickia (Enantia Oliv., non Falc. [Sabiaceae]). 2) In 1986 Van Setten & Koek-Noorman performed a research on leaf anatomical characters in Annonaceae. According to them the genera of the Unonopsis group P.J.M. Maas et al.: Revision of Bocageopsis, Onychopetalum, and Unonopsis 415 sensu Fries (1959) all had in common the complex structure of the primary vein, the presence of silica bodies, and idioblastic (oil) cells in the epidermis. 3) In Van Heusden’s (1992) survey of floral characters in Annonaceae a Unonopsis group is distinguished including only the three genera Bocageopsis, Onychopeta- lum, and Unonopsis, characterized by valvate sepals and petals (mostly white and small), simple hairs, and with 1–6, mostly lateral ovules. Van Heusden noticed some general resemblance to the flowers of her Cremastosperma group which, however, have imbricate sepals and petals, and only 1 ovule. (Van Heusden also reported rarely imbricate sepals in Onychopetalum, and slightly imbricate petals in Bocageopsis and Onychopetalum, beside the standard valvate condition. The present authors could not confirm this.) 4) Van Setten & Koek-Noorman (1992), in their study of fruits and seeds of almost all genera within the family, included the 3 genera under revision and the Afri- can genus Annickia in their group 7, defined by a distinct, canaliculate raphe (a character found outside this group only in one species of Diclinanona, and in Mosannona xanthochlora), and by few, laterally placed, pitted seeds with spini- form ruminations. However, similarly pitted seeds with spiniform ruminations are also found in some other groups. 5) Doyle et al. (2000) performed a combined analysis of pollen morphological and molecular (rbcL) data. They placed Unonopsis in the Malmeoid clade together with the Neotropical genera Ephedranthus and Malmea, the African genus An- nickia, and an Asian species of Polyalthia (P. sumatrana). Bocageopsis and Onychopetalum were not among the genera investigated. 6) Richardson et al. (2004), in a study on historical biogeography of the cosmopolitan families Annonaceae and Rhamnaceae, carried out phylogenetic analyses based on rbcL and trnL-F plastid DNA sequences. Bocageopsis, Onychopetalum, and Unonopsis are placed as a strongly supported clade in the so-called Short Branch Clade. This is confirmed shortly thereafter in a study by Pirie et al. (2006) on the basis of more plastid sequence data. The relation between the Unonopsis group and other groups remains to be investigated. Recently Botermans (2006, unpublished) performed a phylogenetic analysis of the genera Bocageopsis, Onychopetalum, and Unonopsis based on plastid and nuclear sequence data. She concluded that the Unonopsis group as already recognized by ear- lier taxonomists is a monophyletic one. Unonopsis according to her is a monophyletic genus, too. Bocageopsis and Onychopetalum proved to be difficult to distinguish due to a lack of sufficient informative characters. MATERIAL AND METHODS Herbarium material was investigated from the following herbaria: A, AAU, B, BM, BR, BRG, BRIT, C, CAY, CEPEC, COL, CR, CVRD, DUKE, E, EAP, ECON, F, G, GB, GH, HBG, HUA, IAN, INB, INPA, JAUM, K, L, LA, LE, LPB, M, MBML, MEXU, MG, MICH, MO, MY, NA, NY, OXF, P, PMA, PORT, QCA, QCNE, RB, S, SCZ, SP, SPF, U, UC, US, VEN, W, WAG, WIS, WU, Z. For terms relating to shape we used the terminology recommended and/or used by the Systematics Association Committee for descriptive terminology (1962). Descriptive 416 BLUMEA