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Manual de Plantas de Costa Rica

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The Cutting Edge

Volume XII, Number 4, October 2005

News and Notes | Recent Treatments | Leaps and Bounds | Germane Literature | Season's Pick | Annotate your copy

Anderberg, A. A., P. Eldenäs, R. J. Bayer & M. Englund. 2005. Evolutionary relationships in the Asteraceae tribe Inuleae (incl. Plucheeae) evidenced by DNA sequences of ndhF; with notes on the systematic positions of some aberrant genera. Organisms Diversity Evol. 5: 135–146.

These analyses show Pluchea as "non-monophyletic," but convey nothing useful to us, since neither the generic type nor the sole Costa Rican representative [P. carolinensis (Jacq.) G. Don] was included in the study.

Bell, C. D. & M. J. Donoghue. 2005. Phylogeny and biogeography of Valerianaceae (Dipsacales) with special reference to the South American valerians. Organisms Diversity Evol. 5: 147–159.

Analysis of sequence data from both nuclear and chloroplast DNA suggests that Valeriana is non-monophyletic, with one Old World sp. falling completely outside the group and the largely North American Plectritis nested in a principally South American clade [see also The Cutting Edge 11(2): 7, Apr. 2004]. Similarly nested is Astrephia, considered a priori as a member of Valeriana but formerly (as in the Flora of Panama) often segregated. Classificatory options are not explicitly addressed, presumably because of the authors’ assessment of their results as "weakly supported." However, because the generic type (the European Valeriana pyrenaica L.) occurs in a small clade separate from the New World contingent, eventual repercussions are a possibility for us.

Chiron, G. R. 2005. Contribution à l’étude de Prosthechea section Parviloba (Orchidaceae). Richardiana 5: 129–153.

The portion of this paper of interest to us is a consideration of "the various taxa formerly treated as synonyms of Prosthechea vespa" ("formerly," in the orchid world, apparently meaning up until about three weeks ago). As we understand it (grappling with the French text), the name Prosthechea vespa (Vell.) W. E. Higgins is henceforth to be restricted to a sp. that is endemic to a relatively small area in southeastern Brazil. Central American material called P. vespa in the Manual—and, for many years before that, Encyclia vespa (Vell.) Dressler—belongs to a distinct sp., ranging southward to Peru and Venezuela, for which the name Prosthechea crassilabia (Poepp. & Endl.) Carnevali & I. Ramírez is accepted as correct. Includes a composite line drawing of P. crassilabia and a black-and-white photo of a flower, as well as a non-indented key to all 10 spp. in the group and discussions and illustrations of most of the other nine (all South American).

Craven, L. A. 2005. Malesian and Australian Tournefortia transferred to Heliotropium and notes on delimitation of Boraginaceae. Blumea 50: 375–381.

The stage is now set for the deletion, from botanical annals, of the venerable genus name Tournefortia. Pursuant to recent molecular studies [see, e.g., The Cutting Edge 11(2): 7, Apr. 2004], the present author acts to incorporate Tournefortia sect. Tournefortia into Heliotropium by validating the necessary new combinations and nomina nova for the Malesian and Australian members of the group (which are relatively few). More significantly, he formally cements the primacy of "the more speciose and more widely distributed" Heliotropium over Tournefortia (the names have equal priority) by coining a nomen novum (Heliotropium verdcourtii Craven) for the generic type of Tournefortia, the neotropical T. hirsutissima L. Although the last-mentioned sp. occurs in Costa Rica (in several of its distinctive guises), Craven’s binomial will probably never come into actual use, unless the five or more sp.-rank synonyms of T. hirsutissima all prove to represent different spp. The author eschews "automatic’ transfer" of the many Central and South American spp. of Tournefortia to Heliotropium, there being no recent taxonomic revision of the group. He now believes that Heliotropium "should be expanded to include all members of Heliotropioideae," i.e, proposed segregates such as Euploca and Myriopus, in addition to Tournefortia s. str. Regarding the delimitation of Boraginaceae, an inclusive concept is advocated, subsuming (as subfamilies) the traditional Hydrophyllaceae and Lennoaceae, as well as five traditionally boraginaceous subtaxa that have been recognized at family rank (Cordiaceae, Ehretiaceae, Heliotropiaceae, etc.) by some recent workers (e.g., Gottschling & Miller and Gottschling et al., this column); to this end, Boraginaceae subfam. Lennooideae (Solms) Craven is validated as a new combination. Only Hydrolea (formerly in Hydrophyllaceae) is excluded, banished to Hydroleaceae, of the order Solanales. The Manual is presently on course to treat Hydrophyllaceae (including Hydrolea) and Lennoaceae as distinct families.

Dessein, S. 2003. Systematic studies in the Spermacoceae (Rubiaceae) . Ph.D. thesis, Katholieke Univ. Leuven, Belgium. 407 pp.

We don’t usually concern ourselves with theses, but this is one of those slickly bound, European numbers that constitute effective publication in the eyes of the powers that be. Each of the 12 chapters (grouped in four "parts") is formatted as a separate publication (except that all the "references" are massed at the end), so we can reasonably expect to see this material again somewhere down the line; indeed, several of the chapters have already been published, in one form or another. We are mainly interested in two that have not (as far as we are aware): Chapter 5, "A survey of the Spermacoceae s. s., with a morphological portrait of the genera," encapsulating the important classificatory results and implications of the phylogenetic analyses detailed in Chapter 4, "Molecular data provide answers and evoke new questions about the phylogeny of the Spermacoceae s. s." Tribe Spermacoceae is familiar to all neotropical botanists as a taxonomically perplexing group of mainly herbaceous, often weedy Rubiaceae centering on Borreria and/or Spermacoce. The analyses of ITS and rps16 intron sequences give strong support to most of the genera traditionally accepted in the tribe, including Crusea, Mitracarpus, and Richardia, as well as Galianthe Griseb., a controversial yet "readily diagnosed" Diodia segregate with at least one sp. reported from Costa Rica. The last-mentioned genus is accordingly polyphyletic, with "species…scattered over the whole tree." Of the Diodia spp. attributed to Costa Rica, D. brasiliensis Spreng. belongs in Galianthe, while D. apiculata (Willd. ex Roem. & Schult.) K. Schum. and D. teres Walter are provisionally accommodated in the oligotypic Diodella Small; however, the status of Diodia sarmentosa Sw. and D. serrulata (P. Beauv.) G. Taylor (the former known in Costa Rica only from Isla del Coco) remains unresolved. It was also judged "impossible to make a sound conclusion" regarding the most contentious problem in the tribe, viz., the generic delimitation of Spermacoce; however, the author opts to "tentatively promote a wide circumscription," to include, e.g., Borreria and Hemidiodia. Chapter 5 features a formal description of tribe Spermacoceae s. str., a key (non-indented) to accepted genera, and an alphabetical catalog of said genera; each catalog entry includes bibliographic and typological data, number of spp., a distribution summary (with map), a formal description, commentary, and at least one drawing or photo (the latter often depicting pollen). Incidentally, the monotypic genus Tobagoa (which perhaps occurs in Costa Rica) is considered different "enough from the other members of the Spermacoceae" to merit generic status, though it was not included in the molecular studies. The remaining chapters deal mainly with pollen morphology and the phylogeny and taxonomy of African members of the tribe. No taxonomic novelties are validated in this volume.

On several occasions, the author makes the point that previous workers on tribe Spermacoceae have been overly preoccupied with a single character, the mode of fruit dehiscence, and have thus overlooked other characters of greater importance in delimiting natural taxa.

Edwards, E. J., R. Nyffeler & M. J. Donoghue. 2005. Basal cactus phylogeny: implications of Pereskia (Cactaceae) paraphyly for the transition to the cactus life form. Amer. J. Bot. 92: 1177–1188.

Analyses of DNA sequence data suggest that Pereskia is paraphyletic, with respect to the entire remainder of Cactaceae. The sole Pereskia sp. native in Costa Rica, P. lychnidiflora DC., occurs in a clade basal to the rest of the family, including a second Pereskia clade; the latter clade harbors the generic type, P. aculeata Mill. Pereskia grandifolia Haw., cultivated in Costa Rica, belongs to the same clade as P. aculeata. Thus, if this scenario holds, the two last-mentioned spp. would remain in Pereskia, while P. lychnidiflora would be on the outs. However, the authors forego nomenclatural changes pending confirmation with additional genes, noting that "most of the basal structure of our tree is contributed by the phyC gene, so it may be…a gene tree rather than the cactus species tree."

Estrada Ch., A. & N. Zamora V. 2004. Riqueza, cambios y patrones florísticos en un gradiente altitudinal en la cuenca hidrográfica del río Savegre, Costa Rica. Brenesia 61: 1–52.

Regular readers of this rag will be aware of the long-term project, financed largely by the Spanish government, to assess the potential for "sustainable development" of the Río Savegre basin, on the northern slope of the Costa Rican Cordillera de Talamanca [see, e.g., The Cutting Edge 8(2): 1, Apr. 2001 ]. Some results of the botanical inventory, shouldered jointly by CR and INB, were presented rather informally in a general work characterizing the various ecosystems in the area [see The Cutting Edge 11(2): 3–4, Apr. 2005] and featuring unvouchered lists of plants collected and observed. Here we get the real deal: the entire vascular flora of the region, analyzed and discussed from every relevant perspective (with a variety of maps, graphs, and tables) on the basis of an exhaustive, extensively vouchered list of every sp. detected (some records lack vouchers and are qualified as "Observ.," and at least a few of the vouchers are, technically speaking, from outside the area). The total number of spp. actually detected was 2152 (ca. 22% of the country total), yielding a statistically estimated grand total of 3290 spp. Asteraceae, Rubiaceae, Melastomataceae, and Orchidaceae (in descending order) were the most diverse families, while Piper, Elaphoglossum, Miconia, and Peperomia were the most diverse genera. Species diversity was highest in the 500–2000 m elevational band. The regional flora includes 132 sp. that are endemic to Costa Rica, including five that are claimed as endemic to the study area: Bartlettina silvicola (B. L. Rob.) R. M. King & H. Rob. (Asteraceae), Chamaedorea incrustata Hodel, G. Herrera & Cascante and C. piscifolia Hodel, G. Herrera & Cascante (Arecaceae), Lacmellea zamorae J. F. Morales (Apocynaceae), and Passiflora gilbertiana J. M. MacDougal (Passifloraceae). Finally, numerous significant discoveries made during the inventory are enumerated, including six country records and nine other spp. considered generally rare or scarce.

Farjon, A. 2005. A monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew, U. K. 643 pp.

This magnificent, large-format tome, illustrated superbly by the author himself, is replete with detailed and authoritative information on Cupressaceae (including Taxodiaceae) and the monotypic Sciadopityaceae, including keys (non-indented), exhaustive descriptions, and complete synonymy at all levels, comprehensive specimen citations, and indices to scientific names and exsiccatae. Seven introductory chapters cover such topics as history, morphology and anatomy, phylogeny and evolution, the fossil record, and distribution. Of the 31 genera revised, Juniperus is by far the largest, with 52 spp. (of 134 total). No sp. in either family is native in Costa Rica, and cultivated specimens are rarely cited, so the impact on us is minimal; we note only minor adjustments to the Manual Cupressaceae treatment (e.g., the apparent southward extension of the natural range of Cupressus lusitanica Mill. into northern Nicaragua). Suffice it to say that this will endure as the standard work on these groups for many decades to come, and that no one with a serious interest in conifers will be able to live without it.

Gerlach, G. & J. Beeche. 2004. Stanhopeinae mesoamericanae (Orchidaceae). III. Reestablecimiento de Stanhopea ruckeri y una especie nueva: Stanhopea confusa. Lankesteriana 4: 213–221.

The authors’ reinterpretation of the lectotype of the name Stanhopea gibbosa Rchb. f., long used for a Central American sp., leads to the conclusion that the name correctly applies to a sp. of Colombia and Ecuador that has heretofore been known as S. impressa Rolfe (now relegated to synonymy). The Central American sp. (S. gibbosa in the sense of the Manual) is baptized anew as Stanhopea confusa G. Gerlach & Beeche and characterized in full, based on numerous cited collections which (oddly) do not include the Manual voucher for S. gibbosa. Illustrated with both color and black-and-white photos of fresh flowers, as well as a composite line drawing of same. Somehow we overlooked this article for the April Edge (where we reviewed several others in the same issue), and thank Manual correspondent Mario Blanco (FLAS) for the reminder. Tying up some loose ends from our previous issue, our running total of new orchid spp. described from Costa Rica since 1993 now stands at 218.

Gill, D. E. & U. Chavarría García. 2001. The flowering plants of Palo Verde National Park . Privately published, D. E. Gill. 257 pp.

This useful contribution harks back a few years, but is worth highlighting, as we were unaware of it until now and thus failed to cite it in the introductory volume of the Manual. The most significant portion of this work is an artificial key, emphasizing non-technical, vegetative characters, to the 118 families of angiosperms known (to the authors) from Parque Nacional Palo Verde, an important site for ecological research. A master key accesses five major subordinate keys, based on habit and habitat (with one key devoted to marsh herbs). The keys are supplemented by an "annotated list," ordered alphabetically by family, in which each sp. (668 in all) is briefly described and (sometimes) discussed; for some families, a sp. key is provided. The coverage is best for woody plants, with groups less well-known to the authors (e.g., Cyperaceae and Poaceae) "treated poorly," in their own admission. Sometimes provisional (and unvouchered) names are used, as in Acanthaceae, with "Unknown shrub #1" and "Unknown Herb #1" through "#4"—designations that contribute virtually nothing. Ferns and their allies are listed and (often) briefly described at the end of the volume, following an account of plants expected from the site, but not yet recorded. Other supplementary features include a bibliography, glossary, and separate indices to scientific and common names. There are no illustrations. This is an effort that can obviously be much improved upon, but is nonetheless an excellent foundation on which to build. Any biologist or naturalist visiting Palo Verde would need a copy (though we do not know how, or even if, one could be obtained). Ours (MO library) is a revised version of the first (2000) edition.

Gottschling, M. & J. S. Miller. 2005. A new species of Bourreria (Ehretiaceae, Boraginales) from Costa Rica. Novon 15: 425–428.

Bourreria mollis Standl. is of scattered occurrence from southern Mexico to Colombia, but must now be deleted from the floras of Nicaragua and Costa Rica (where it has also been known by the name B. oxyphylla Standl., here considered a synonym). Collections from the two last-mentioned countries answering to the general description of B. mollis are segregated in a new sp. dubbed Bourreria grayumii Gottschl. & Js. S. Mill., unique in the so-called Bourreria baccata Raf. sp.-complex in its flowers with the stamen filaments fully adnate to the corolla tube. It may also be closely related to B. huanita (Lex.) Hemsl. (mentioned only in the abstract). The new sp. is virtually restricted to northernmost Costa Rica, where it occurs from ca. 0–600+ m elevation in the Cordillera de Guanacaste, the Río Sapoá basin, and the Llanura de Los Guatusos; most collections are from the Reserva Nacional de Vida Silvestre Caño Negro. A single collection, Moreno 26240, extends the range to southernmost Nicaragua (three other collections cited under Bourreria mollis and B. oxycarpa in Flora de Nicaragua were apparently misidentified). Features a distribution map and a superlative composite line drawing.

-- , -- , M. Weigend & H. H. Hilger. 2005. Congruence of a phylogeny of Cordiaceae (Boraginales) inferred from ITS1 sequence data with morphology, geology, and biogeography. Ann. Missouri Bot. Gard. 92: 425–437.

The a priori consensus treatment of this "supergroup" collaboration divides the traditional Boraginaceae into four families, Boraginaceae s. str., Cordiaceae, Ehretiaceae, and Heliotropaceae, while maintaining Hydrophyllaceae (sans Hydrolea) and Lennoaceae as distinct (see under Craven, this column, for an alternative view). Cordiaceae, the focus of this study, consists principally of the large (ca. 350 spp.), pantropical, and important genus Cordia. According to the results of these analyses, Cordiaceae is monophyletic as long as it includes the oligotypic, South American genera Auxemma, Patagonula, and Saccellium, all of which have been referred to Ehretiaceae, yet are nested within Cordia. The last-mentioned genus is here resolved into four major clades: "Collococcus," with C. collococca L. and C. panamensis L. Riley (to mention only those Costa Rican representatives included in the study); "Myxa," with C. dentata Poir. as well as the generic type, C. myxa L.; "Sebestena" (the most weakly supported of the four clades), with C. alliodora (Ruiz & Pav.) Oken; and "Varronia," with C. bifurcata Roem. & Schult. and C. curassavica (Jacq.) Roem. & Schult. The "Varronia" clade, sister to the other three, is a "well-differentiated taxon" that is distinct in its morphology, distribution, and ecology; one senses that the authors would be inclined to elevate it to generic rank (presumably under the name Varronia P. Browne), though they never explicitly say as much. However, their stated intention to formally submerge the three afore-mentioned South American genera (nested in the "Sebestena" clade) into Cordia implies that no additional splitting is contemplated.

Harrington, M. G., K. J. Edwards, S. A. Johnson, M. W. Chase & P. A. Gadek. 2005. Phylogenetic inference in Sapindaceae sensu lato using plastid matK and rbcL DNA sequences. Syst. Bot. 30: 366–382.

The abstract of this paper states that "very robust" support was found for "a broadly defined Sapindaceae incorporating Aceraceae, Hippocastanaceae, and Xanthoceras." However, upon closer inspection, this claim proves somewhat misleading. The notion of Aceraceae and Hippocastanaceae as nested within Sapindaceae s. str. depends mainly upon the ostensibly basal position of the monotypic, Chinese Xanthoceras. But the last-mentioned genus emerged as basal (and with "only moderate support") in just one of the four analyses (the combined analysis); in the three other published cladograms, it is an integral component of the Sapindaceae s. str. clade. Buried in the discussion is the authors’ admission that "the relationships of Xanthoceras remain uncertain." Despite this, they advocate an infrafamilial classification of Sapindaceae s. l. that would include a monotypic subfam. Xanthoceroideae, as well as a subfam. Hippocastanoideae, the latter with two tribes corresponding to the former Aceraceae and Hippocastanaceae. For tribe Hippocastaneae to remain monophyletic, it must include Handeliodendron, another monotypic, Chinese genus, which has been associated with Hippocastanaceae in the past. Having accomplished that, there is no reason, cladistically speaking, that tribes Acereae and Hippocastaneae could not be ranked as families (preserving traditional concepts), unless Xanthoceras does indeed prove to be basal—in which case, family status for Xanthoceroideae would also be an option.

Hovenkamp, P. H. & F. Miyamoto. 2005. A conspectus of the native and naturalized species of Nephrolepis (Nephrolepidaceae) in the world. Blumea 50: 279–322.

This very nearly meets the standards of a revision, except that no specimens (other than types) are cited. Otherwise, we get complete synonymy and typology, adequate descriptions at all levels, a key to spp. (dichotomous, but not indented), distribution summaries (including maps), illuminating discussions of variable length, a section on excluded names (just one), and an index to scientific names. Nephrolepis is a pantropical genus with 19 spp. here accepted, of which some are important horticulturally; hybrids and "cultivars and monstrosities" are considered separately, at the end of the paper. There is just one major surprise involving a sp. occurring in Costa Rica: the new combination Nephrolepis brownii (Desv.) Hovenkamp & Miyam. (based on Nephrodium brownii Desv.) is validated to replace N. hirsutula (G. Forst.) C. Presl (regarded as misapplied) and N. multiflora (Roxb.) F. M. Jarrett ex C. V. Morton (reduced to synonymy), both of which have been long used (by different authors) for an Old World sp. widely naturalized in the Neotropics. The brief introductory section, illustrated with black-and-white photos (depicting indument) and a composite line drawing (of fertile pinnae), addresses taxonomic history, various aspects of morphology, karyology, distribution, cultivation, and identification.

Jaramillo, M. A. & R. Callejas. 2004. Current perspectives on the classification and phylogenetics of the genus Piper L. Pp. 179–198 in, L. A. Dyer & A. D. N. Palmer (eds.), Piper: a model genus for studies of phytochemistry, ecology, and evolution. Kluwer Academic/Plenum Publishers, New York, etc. 214 pp.

ITS sequence data show Pothomorphe to be firmly embedded in Piper (Piperaceae), while other molecular analyses support Sarcorhachis as distinct within the family. This book is full of other interesting articles, mainly of an ecological nature.

Lewis, G., B. Schrire, B. Mackinder & M. Lock (eds.). 2005. Legumes of the world . Royal Botanic Gardens, Kew, U. K. 577 pp.

Packed with gaudy graphics and color photos, this is one of those rare and special books that can more than hold its own on the coffee table while maintaining cutting-edge scientific integrity. It is roughly the legume equivalent of Genera palmarum (Uhl & Dransfield, 1987) or The genera of Araceae (Mayo et al., 1997), but Fabaceae has so many genera (727 are acccepted here) that the focus is necessarily at the tribal level, with the individual generic entries much abbreviated (and set in very small type). Two introductory chapters address classification, economic importance, and biogeography. The body of the work is a catalog of tribes and genera, divided into three main parts according to the traditional subfamilial classification of Fabaceae (though it is not embraced by the authors); each of these parts is further divided according to tribes (36 in all, with 28 in subfam. Papilionoideae), under which are grouped the genus entries. A major drawback (in our view) is that both the tribes and genera are ordered non-alphabetically. Recent, molecular-based cladograms inform each tribal discussion, and clearly played a role in the (generally rather narrow) circumscriptions of genera. Every genus is illustrated with at least one color photo or composite line drawing, of uniformly excellent quality. We note several taxonomic decisions of relevance to Costa Rican floristics, e.g.: Barbiera is maintained as distinct from Clitoria, Cymbosema from Dioclea, and both Deguelia and Muellera from Lonchocarpus, while Sclerolobium is synonymized under Tachigali. Perhaps most surprising is the dissolution of Caesalpinia (though it never really seemed like a cohesive unit); based on research that we have unaccountably overlooked, it is here fragmented into nine smaller genera. A genus of some 140 spp. in its traditional sense, Caesalpinia s. str. now comprises just 25 spp., with the familiar ornamental C. pulcherrima (L.) Sw. apparently the only Costa Rican representative. Of the eight remaining segregate genera, at least three occur in Costa Rica: Guilandina [with the former Caesalpinia bonduc (L.) Roxb.], Libidibia [harboring Caesalpinia coriaria (Jacq.) Willd.], and Poincianella (with Caesalpinia eriostachys Benth. and C. exostemma DC.). We glean that Caesalpinia platyloba S. Watson is perhaps referrable to a fourth segregate, Coulteria (though the indicated combination is unavailable). Acacia is accepted as polyphyletic, and the ongoing (as of press time) brouhaha is discussed in detail, but the genus is maintained provisionally in the traditional sense. Considering the immense diversity (19,237 spp.!) and enormous economic importance of Fabaceae (or Leguminosae, as the editors prefer) on a worldwide scale, this grand volume will certainly become an indispensable reference for botanists of every ilk.

Luer, C. A. 2005. Systematics of Dryadella (Orchidaceae). Pp. 1–56 in, C. A. Luer, Icones pleurothallidinarum XXVII. Monogr. Syst. Bot. Missouri Bot. Gard. 103: 1–311.

Dryadella must be one of the last non-gigantic pleurothallid genera that had not been fully revised by Manual contributor Carlyle A. Luer. With 10 spp. (none from Costa Rica) here described as new, the generic total now stands at 48. For us, this treatment perhaps raises more questions than it answers. The Costa Rican sp. total of four, as presented in Luer’s Manual treatment, remains unchanged, but we have mysteriously gained one sp. and lost another. Unimpacted are Dryadella gnoma Luer, D. guatemalensis (Schltr.) Luer, and D. odontostele Luer. But D. sororcula Luer has vanished, and we are unable to find the Manual voucher cited anywhere (the absence of an index to exsiccatae does not help); a different voucher, cited in Pupulin’s "Catálogo revisado y anotado de las Orchidaceae de Costa Rica" (Lankesteriana 4: 1–88. 2004), is duly cited under D. sororcula, but with a Panamanian locality! Compensating for the loss of D. sororcula is the addition of Dryadella fuchsii Luer, ranging from El Salvador and Honduras to (now) Costa Rica, for which it is vouchered by two Paul Standley collections from near Tilarán. Features full synonymy, bibliography and typology, detailed descriptions at all levels, a (non-indented) key to spp., an index to scientific names, and a composite line drawing of every sp., as well as a photographic frontispiece depicting a living plant in color.

-- . 2005. Systematics of Acronia section Macrophyllae-fasciculatae. Pp. 57–274 in, C. A. Luer, Icones pleurothallidinarum XXVII. Monogr. Syst. Bot. Missouri Bot. Gard. 103: 1–311.

He’s really going to do it! This is the first revision in this series to implement the author’s sweeping, post-Manual reclassification of Pleurothallis (Orchidaceae) into at least 27 smaller genera [see The Cutting Edge 11(3): 10–11, Jul. 2004]. Acronia is cobbled together from two former subsections of sect. Pleurothallis (Acroniae and Macrophyllae-fasciculatae) and a former series of subsect. Pleurothallis (Amphygiae), each of which becomes a section of Acronia. As two of these component taxa have already been revised by Luer [see The Cutting Edge 6(1): 8, Jan. 1999], the body of this paper comprises a formal taxonomic revision of Acronia sect. Macrophyllae-fasciculatae (Lindl.) Luer (stat. nov.). However, new combinations in Acronia (all credited to Luer) are provided for the members of sects. Acronia and Amphygia Luer, including the following spp. occurring in Costa Rica: Pleurothallis dentipetala Rolfe ex Ames, P. imitor Luer, P. longipedicellata Ames & C. Schweinf., P. luctuosa Rchb. f., P. rowleei Ames, and P. volcanica Luer.

Acronia sect. Macrophyllae-fasciculatae, one of the largest sp.-blocs of Pleurothallis s. l. (with ca. 16% of the Costa Rican spp.), is characterized by a cespitose habit, sessile leaves, commonly cordate at the base, and single flowers with connate lateral sepals. This revision, with all the standard features of this series (see foregoing entry), accepts 213 spp., of which 38 occur in the Mesoamerican region. New combinations in Acronia (all credited to Luer) are validated for the following spp. attributed to Costa Rica in the Manual: Pleurothallis aurita C. Schweinf., P. bitumida Luer, P. bothros Luer, P. cardiothallis Rchb. f., P. chavezii Luer, P. compressa Luer, P. discoidea Lindl., P. dorotheae Luer, P. excavata Schltr., P. fantastica Ames & C. Schweinf., P. homalantha Schltr., P. isthmica Luer, P. leucantha Schltr., P. oncoglossa Luer, P. palliolata Ames, P. peculiaris Luer, P. phyllocardia Rchb. f., P. phyllocardioides Schltr., P. radula Luer, P. rhodoglossa Schltr., P. scaphipetala Luer, and P. tonduzii Schltr. However, no Costa Rican specimens are cited for either P. discoidea or P. peculiaris (and again, the lack of an index to exsiccatae impedes our search for citations of the Manual vouchers). Also referred to Acronia are Pleurothallis canaligera Rchb. f., P. matudana C. Schweinf., and P. rectipetala Ames & C. Schweinf., none formally treated in the Manual, but all mentioned as having been reported from Costa Rica (P. rectipetala under its synonym, P. scitula Luer); the Costa Rican reports of P. matudana and P. rectipetala (both from Pupulin’s "Catálogo"; see foregoing entry) are here confirmed, but not that of P. canaligera (incidentally, the name Pleurothallis rectipetala appears in the Manual as a synonym of P. phyllocardia). Pleurothallis leucantha was considered to include P. sanchoi Ames in the Manual, but here the two concepts are segregated, with the former restricted to Guatemala; thus Pleurothallis (or Acronia) sanchoi reverts to being the correct name for Costa Rican material, with P. gonioglossa Schltr.—treated as a distinct sp. in the Manual—in synonymy. We suffer another net sp. loss with the formulation of Acronia bivalvis (Lindl.) Luer, "the greatest catch-all or waste basket of the genus," which absorbs both Pleurothallis angusta Ames & C. Schweinf. and P. cardiantha Rchb. f. Surprisingly, none of the 23 new spp. described in this treatment occurs in Costa Rica.

-- . 2005. Validation of names cited in Monogr. Syst. Bot. Missouri Bot. Gard. 95, 2004. Pp. 310–311 in, C. A. Luer, Icones pleurothallidinarum XXVII. Monogr. Syst. Bot. Missouri Bot. Gard. 103: 1–311.

Some names that were invalidly published, for various technical reasons, in the work referenced in the title [see The Cutting Edge 11(3): 10–11, Jul. 2004] are here made good. A few, in the pleurothallid segregate genera Aberrantia and Unguella, pertain at least tangentially to Costa Rica.

Morales, J. F. 2005. Estudios en las Apocynaceae neotropicales XIII: revisión del género Temnadenia (Apocynoideae, Echiteae). Candollea 60: 207–231.

Although the South American Temnadenia is of no concern to us, this paper receives honorable mention for presenting a key (dichotomous, but non-indented) to all the genera of Apocynaceae tribe Echiteae in the Neotropics. At least seven of these are represented in Costa Rica.

Peng, C.-I, C. L. Schmidt, P. C. Hoch & P. H. Raven. 2005. Systematics and evolution of Ludwigia section Dantia (Onagraceae). Ann. Missouri Bot. Gard. 92: 307–359.

The titular taxon is "a polyploid complex (x = 8) of five species that are distributed mainly in the Coastal Plain of the southeastern United states, although two species…have much broader ranges in North America." One of the latter, Ludwigia palustris (L.) Elliott, reaches Costa Rica, and is thus the only member of this group that interests us. Features synonymy and typology at all levels, formal descriptions of the genus, section, and all included spp., a key to spp., rather detailed discussions, representative specimen citations, distribution maps, and a separate treatment of five interspecific hybrids. The introductory pages address taxonomic history, morphological characters, reproductive biology, distribution, and hybridization (with original cytological data). Both the introductory and systematic parts are illustrated with excellent composite line drawings.

Plunkett, G. M., P. P. Lowry II, D. G. Frodin & J. Wen. 2005. Phylogeny and geography of Schefflera: pervasive polyphyly in the largest genus of Araliaceae. Ann. Missouri Bot. Gard. 92: 202–224.

Impending doom for Schefflera as we know it has already been forecast in previous papers by this same group addressing the phylogeny and classification of Araliaceae as a whole [see, e.g., The Cutting Edge 12(1): 9–10, Jan. 2005]. Here the focus is narrowed to Schefflera alone, with devastating consequences. Analyses of both nuclear (ITS) and plastid (trnL-trnF) DNA sequences, involving 68 Schefflera spp., confirm the genus to be (as advertised) "markedly polyphyletic," comprising five major clades "scattered among all the major lineages of Araliaceae." Strong geographic correlations characterize the five major clades, one of which (the most weakly supported) comprises all the New World Schefflera spp., and is sister to a clade including all the Asian spp. plus Heteropanax and Tetrapanax. A third Schefflera clade contains the African-Malagasy spp., while the remaining two are centered in the southwest Pacific region. Because the generic type (S. digitata J. R. Forst. & G. Forst.) resides in one of the Pacific clades, the name Schefflera will certainly be lost to neotropical floristics. Beyond that, little speculation is possible, because the sampling of the New World contingent (an unusually diverse lot, as detailed herein) was "rather limited" (7 spp.) and "insufficient to evaluate relationships." Indeed, the overall sample size of 68 spp. (just 8% of the estimated total of 900 spp. of Schefflera s. l.) "preclude[d] any formal taxonomic recircumscriptions" in any of the lineages involved. Efforts to expand the sample size and analyze each of the five major clades individually are said to be underway.

Pupulin, F. 2005. Ciliate dichaeas; Dichaea hystricina and Dichaea ciliolata: two species in one and an interesting variation. Orchids (West Palm Beach) 74: 678–683.

Study of living plants in cultivation, in preparation for a forthcoming revision of Costa Rica Dichaea spp. (Orchidaceae), leads to the conclusion that D. hystricina Rchb. f. and D. ciliolata Rolfe—recognized as distinct in Bob Dressler’s Manual treatment—are conspecific. The author "was unable to detect any substantial difference among the flowers produced" by the ostensibly different plants, nor could he find any correlation "between the shape of the plants and the morphology of their flowers." Moreover, "the plants are able to shift from one morph to the other along a single stem." On the basis of this evidence, D. ciliolata and D. lycopodioides Rchb. f. ex Kraenzl. (both based on Costa Rican types), together with D. selaginella Schltr. (based on a Colombian type), are formally synonymized under D. hystricina (based on a Cuban type). A weakness of this argument is that all the living plants studied were (as far as can be determined from the scant data provided) collected in Costa Rica; the "real" Dichaea hystricina (in the sense of its Cuban type) was not represented verifiably. Thus, while the author may well be correct in his determination that all the Costa Rican material in this group comprises a single entity, the application of the name D. hystricina to any Costa Rican plants must still be considered tentative. Illustrated with numerous color photos of living plants.

-- & D. Bogarín. 2005. The genus Scelochilus; determining the number of species in Central America. Orchids (West Palm Beach) 74: 526–533.

To make a long story short, there are (according to these authors) two: Scelochilus tuerckheimii Schltr. (Orchidaceae), ranging from southern Mexico to northern Nicaragua, and S. aureus Schltr., of Costa Rica (whence the type) and western Panama. This conclusion is at odds with Bob Dressler’s Manual treatment, in which the name Scelochilus tuerckheimii was used for Costa Rican material, with S. aureus cited in synonymy. There are some nice color photos of S. aureus here, plus a fine, original composite drawing by the authors, but no key or descriptions formalizing the alleged differences. Synthesizing from the text and illustrations, one learns that, compared to our Costa Rican plants, S. tuerckheimii s. str. has smaller flowers, in which the labellum is apically acute (vs. "emarginate to bilobulate") and with subequal "horns" (vs. the proximal "horns" much shorter than the distal ones).

Rohwer, J. G. & B. Rudolph. 2005. Jumping genera: the phylogenetic positions of Cassytha, Hypodaphnis, and Neocinnamomum (Lauraceae) based on different analyses of trnK intron sequences. Ann. Missouri Bot. Gard. 92: 153–178.

We are interested only in one of the incidental results of this study, viz., that Beilschmiedia is "clearly paraphyletic" with respect to the Old World genera Endiandra and Potameia (both of moderate to large size) This could eventually have repercussions for us if it were decided to split Beilschmiedia into smaller entities, rather than lump the afore-mentioned genera ("further studies" being needed to resolve the issue). The generic type is an Old World sp.

Roncal, J., J. Francisco-Ortega, C. B. Asmussen & C. E. Lewis. 2005. Molecular phylogenetics of the tribe Geonomeae (Arecaceae) using nuclear DNA sequences of phosphoribulokinase and RNA polymerase II. Syst. Bot. 30: 275–283.

This is one of those rare molecular studies that does not portend grave consequences for familiar taxa (at least, in the Mesoamerican region). Tribe Geonomeae is supported as monophyletic, as are the genera Geonoma and Pholidostachys. Calyptrogyne is nested within the oligotypic, West Indian Calyptronoma, but the former name is older. The dispositions of Asterogyne and Welfia could not be "fully resolved and their confirmation as genera await [sic] further study."

Sánchez-Acebo, L. 2005. A phylogenetic study of the New World Cleome (Brassicaceae, Cleomoideae). Ann. Missouri Bot. Gard. 92: 179–201.

Sequence analyses of the chloropast non-coding region trnH-psbA resolve Cleome rather tenuously into three clades, one African and the others neotropical. Nested within one of the neotropical clades is Podandrogyne, which accordingly "should not be recognized as a genus." Were Podandrogyne to be sunk in Cleome, the name C. decipiens Triana & Planch. would perhaps be applicable to the sole sp. occurring in Costa Rica.

Sánchez-Vindas, P., L. J. Poveda Álvarez & J. T. Arnason. 2005. Guía dendrológica costarricense . Herb. Juvenal Valerio Rojas, Heredia, Costa Rica. 226 pp.

This concise volume (a manual in the purest sense of the word) is designed quite effectively as a means for foresters and other interested parties to identify Costa Rican trees (mostly native) to family level exclusively on the basis of vegetative features. Among the 120 families featured, a few oddball genera and species are inevitably singled out as well. Here’s how it works: families or (much more often) groups of families are isolated in the terminal leads of a (mostly) polychotomous key that dictates the organization of the volume. The book is divided into eight main sections, or groups of families, delimited by gross characters of the stipules (presence vs. absence) and leaves (simple vs. compound, and opposite or verticillate vs. alternate or fasciculate); these eight groups are enumerated in the table of contents, which does double-duty as the first polychotomy of the key (though a "clave maestra" is repeated on the following page). Each main section is headed by a key (comprising the polychotomies nested under the main lead), followed by detailed accounts of each of the families under consideration, in alphabetical order. The family accounts, mostly occupying a single page, each include a brief enumeration of the diagnostic features and taxa represented in Costa Rica, together with a composite line drawing of important characters. An illustrated glossary and general index terminate the volume. The ease of identification varies immensely according to the taxon; at one extreme, it is possible to identify a single genus (Liquidambar, Rhizophora) or even sp. (Caryocar costaricense Donn. Sm., Guaiacum sanctum L.) using the key alone, while at the other extreme one is required to carefully compare many (up to 20 or more) family accounts. The family concepts are traditional, but the coverage is astonishingly comprehensive, including even the most obscure and/or recently discovered taxa (noted in passing: Acanthosyris, Dacryodes, Joosia, Pleodendron, Recchia, Schaefferia). We were unable to find a single non-vegetative character mentioned in the key, the glossary, or any of the family accounts, or depicted in any of the illustrations. Bravo! N.B.: We hope and trust that we have correctly rendered the authorship of this work, given above in exactly the same order as on the cover and spine; however, one of the preliminary pages appears to limit authorship to Poveda and Arnason, with Sánchez-Vindas as illustrator.

Swenson, U. & A. A. Anderberg. 2005. Phylogeny, character evolution, and classification of Sapotaceae (Ericales). Cladistics 21: 101–130.

This allegedly represents "the first cladistic study of…Sapotaceae based on both morphological and molecular data," the latter in the form of sequences of the ndhF gene. We learn that the three principal genera in the Mesoamerican region are all on shaky ground. First, "neither Chrysophyllum nor Pouteria are monophyletic in their current circumscriptions." This is not a big deal for Pouteria, from our perspective, since "all New World species form a clade," and the generic type (P. guianensis Aubl.) is neotropical. But Chrysophyllum is in trouble; the type sp., the widely cultivated C. cainito L., is paired with C. oliviforme L. (also occurring in Costa Rica) in a clade distantly removed from the rest of the genus, including C. argenteum Jacq. and C. venezuelanense (Pierre) T. D. Penn. (the only other Costa Rican representatives sampled). Sideroxylon is paraphyletic with respect to the monotypic, African Argania and the oligotypic, Polynesian Nesoluma; the authors stipulate that additional phylogenetic studies are needed to determine whether a narrower generic concept is indicated (in which case, once-familiar names like Bumelia, Dipholis, and Mastichodendron could resurface). Among the other genera included in the study, Pradosia was strongly supported as monophyletic, Micropholis moderately so, and Manilkara but weakly.

Warwick, S. I. & C. A. Sauder. 2005. Phylogeny of tribe Brassiceae (Brassicaceae) based on chloroplast restriction site polymorphisms and nuclear ribosomal internal transcribed spacer and chloroplast trnL intron sequences. Canad. J. Bot. 83: 467–483.

Both Brassica and Diplotaxis, genera that occur adventively (and in cultivation) in Costa Rica, are recklessly polyphyletic. We may be on safe ground with Brassica, since the adventive B. rapa L. occurs in the same clade as the type sp., the cultivated B. oleracea L.; however, two other Costa Rican adventives, B. juncea (L.) Czerniak. and B. napus L., were omitted from the study. The genus Diplotaxis was first recorded from Costa Rica just two years ago [see The Cutting Edge 10(2): 4, Apr. 2003] in the form of D. tenuifolia (L.) DC., which just happens to be the generic type. But as luck would have it, D. tenuifolia shares a clade with members (including the type) of the genus Eruca, an older name than Diplotaxis!

Wilbur, R. L. & J. L. Luteyn. 2005. Three previously undescribed species of Vaccinium (Ericaceae) from Costa Rica and Panama. Sida 21: 1607–1614.

Just one of these occurs in Costa Rica, the endemic Vaccinium furfuraceum Wilbur & Luteyn, illustrated with a photo of the type and only known specimen. The latter was collected by the redoubtable Gerardo Herrera, at ca. 700 m elevation on the Caribbean slope of the eastern Cordillera de Talamanca. A lengthy description is provided, but no diagnosis, formal or narrative; this is promised, in the opening paragraph, for a forthcoming revision. The name V. furfuraceum was used provisionally in a draft of the yet-to-be-published Manual Ericaceae treatment [see The Cutting Edge 11(2): 2, Apr. 2004], co-written by these same authors.

Wurdack, K. J., P. Hoffmann & M. W. Chase. 2005. Molecular phylogenetic analysis of uniovulate Euphorbiaceae (Euphorbiaceae sensu stricto) using plastid rbcL and trnL-F DNA sequences. Amer. J. Bot. 92: 1397–1420.

The results of this study hint at potential changes involving several genera occurring in Costa Rica, but the rather shallow (albeit broad) sampling permits few substantive conclusions. Euphorbia s. str. is confirmed as polyphyletic, in accordance with other recent work [see The Cutting Edge 10(1): 10, Jan. 2003], but becomes monophyletic with the inclusion of all segregate cyathial genera (Chamaesyce, Pedilanthus, Poinsettia, etc.). Julocroton (with Croton argenteus L. in Costa Rica) is nested within Croton; but the latter is polyphyletic if it includes C. lobatus L. and related lobed-leaved spp., soon to be segregated under the genus name Astraea Klotzsch. Actinostemon and Gymnanthes, sometimes combined under the latter name (as in Flora de Nicaragua), are polyphlyetic even when considered individually; but neither generic type was included in the study, so the consequences for us are unclear. Tragia is paraphyletic, but the generic type (T. volubilis L., one of the three Costa Rican spp.) was not sampled. Sebastiania is wildly polyphyletic, and both Costa Rican spp. were included: S. pavoniana (Müll. Arg.) Müll. Arg. groups with the generic type (S. brasiliensis Spreng.), while S. corniculata (Vahl) Müll. Arg. is distantly removed. The last-mentioned spp. has already (as in Flora de Nicaragua) been treated in the genus Microstachys, and was so regarded a priori for this investigation. Lastly, Alchornea is paraphyletic, but not in a manner that bodes changes for the Costa Rican flora.


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