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The Cutting Edge
Volume XX, Number 1, January 2013
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Agostini, G., S. Echeverrigaray & T. T. Souza-Chies. 2012. A preliminary phylogeny of the genus Cunila D. Royen ex L.
(Lamiaceae) based on ITS rDNA and trnL-F regions. Molec. Phylogen. Evol. 65: 739–747.
The results of this study suggest that Cunila is polyphyletic and “should be…perhaps split into three genera.” The only sp. of Cunila recorded from Costa Rica, C. leucantha Kunth ex Schltdl. & Cham., should be safe according to the scenario postulated by the authors, as it groups in the same clade with the North American C. origanoides (L.) Britton, which serves as the generic type.
Al-Shehbaz, I. A. 2012. A generic and tribal synopsis of the Brassicaceae (Cruciferae). Taxon 61: 931–954.
This useful contribution from Manual Brassicaceae contributor Ihsan Al-Shehbaz (MO) provides basic taxonomic information (typology and synonymy) for the titular family, with the tribes in alphabetical order and the genera nested alphabetically thereunder (excepting 20 not yet assignable to a tribe). Distribution summaries are included for the tribes. In all, 49 tribes and 321 genera are accepted, with a total of 3660 spp. Twenty-seven new combinations and two nomina nova are validated at sp. rank, four generic names are lectotypified, and 11 new synonymies are proposed, though none of these innovations impacts (as far as we can tell) Costa Rica’s small contingent of Brassicaceae. This paper is one of six in this issue grouped under the heading “Phylogeny and systematics of Brassicaceae”; interested parties may wish to investigate further.
Anderson, W. R. & C. C. Davis. 2012. (2091) Proposal to conserve the name Mascagnia against Triopterys
(Malpighiaceae). Taxon 61: 1124–1125.
Recent molecular investigations by these authors have shown that Mascagnia, with about 40 spp. distributed nearly throughout the Neotropics (including three in Costa Rica), is paraphyletic with respect to Triopterys, with just five spp. restricted to the Greater Antilles and Bahamas. And of course, Triopterys is the older name (by a rather comfortable margin), hence the present proposal.
Applequist, W. L. 2012. Report of the Nomenclature Committee for Vascular Plants: 64. Taxon 61: 1108–1117.
We note the following decisions germane to Costa Rican floristics: a proposal [see under “Blanco,” this column, in The Cutting Edge 18(2), Apr. 2011] to conserve Lockhartia oerstedii Rchb. f. against the prior Oncidium mirabile Rchb. f. (Orchidaceae) is not recommended, but the former name appears safe as the Committee voted to reject O. mirabile; a proposal [see under “Schwartsburd,” this column, in The Cutting Edge 18(2), Apr. 2011] to conserve Pteris arachnoidea Kaulf. [the basionym of Pteridium arachnoideum (Kaulf.) Maxon, Dennstaedtiaceae] against both Aspidium brasilianum C. Presl and Pteris psittacina C. Presl is recommended unanimously; a proposal to conserve Acrostichum ebeneum L. (Pteridaceae) with a conserved type is recommended, elevating Pityrogramma ebenea (L.) Proctor from the status of synonym [of P. calomelanos (L.) Link] to accepted name [for the sp. often known as P. tartarea (Cav.) Maxon] and (we hope!) finally quelling a teapot tempest that has brewed for several decades; a proposal [see under “Razafimandimbison,” this column, in The Cutting Edge 18(3), Jul. 2011] to conserve Morinda citrifolia L. (Rubiaceae) with a conserved type is recommended, sparing us from having to replace that name with M. nodosa Buch.-Ham. for a well-known and widespread sp.; a proposal [see under “Whitson,” this column, in The Cutting Edge 18(3), Jul. 2011] to conserve Physalis L. (Solanaceae) with a conserved type is recommended, salvaging that name for ca. 75 New World spp. (which otherwise would have to be transferred to the “never-used” Herschelia T. E. Bowdich), though requiring that the commonly cultivated Asian Physalis alkekengi L. (the original generic type) become Alkekengi officinarum Moench; a proposal [see under “Dressler,” this column, in The Cutting Edge 18(4), Oct. 2011] to conserve Sobralia Ruiz & Pav. (Orchidaceae) with a conserved type is recommended, maintaining that name for the majority of spp. (ca. 100) traditionally included in that genus and that would otherwise have to be transferred to the obscure Cyathoglottis Poepp. & Endl.; and finally, conservation of the name Spermacoce capitata Ruiz & Pav. (Rubiaceae), in use for a South American sp., is recommended against the prior S. capitata P. J. Bergius, which is a relief for us because the latter homonym is apparently “an earlier taxonomic synonym” of Spermacoce suaveolens (G. Mey.) Kuntze, the accepted name for a sp. that occurs in Costa Rica.
Bogarín, D., A. P. Karremans & F. Pupulin. 2012. Three new Lepanthes (Orchidaceae: Pleurothallidinae) from south-east Costa Rica. Lankesteriana 12: 107–114.
All three new spp. are restricted to the Pacific slope in the southern part of Costa Rica and, so far as is known, all are endemic to the country. Lepanthes erubescens Bogarín, Pupulin & Karremans, most similar to L. limbellata Endrés ex Luer, has been found at 450–1300 m elevation in the northern Fila Costeña and the Valle de General; Lepanthes sandiorum Bogarín & Karremans, compared with L. dolabriformis Luer, is known from a single large population at 1778 m elevation in Zona Protectora Las Tablas, in the eastern Cordillera de Talamanca; and Lepanthes sanjuanensis Bogarín & Karremans, compared with L. elegans Luer, has been collected only at the type locality, at 1187 m elevation on Alto San Juan, in the northern Fila Costeña. Amazingly, only the authors and their colleagues have ever managed to find any of these spp. (or so their specimen citations would suggest). According to the authors’ estimation, Lepanthes now comprises “about 120 species” in Costa Rica (vs. just 93 in 2003, when the Manual Orchidaceae treatment was published). All three new spp. are depicted in excellent composite line drawings and color photos of flowers.
Carr, G. F., Jr. 2012. The genus Cycnoches: species and hybrids. Orchids (West Palm Beach) 81(Suppl.): 2–35.
We continue to be mystified and perplexed by the big, gaudy orchids (or is it the people who work on them?). Either trained systematists are completely missing the boat on these things, or amateurs are completely out to lunch. This contribution, by an individual whom we presume to be a hobbyist, includes a checklist of all the Cycnoches spp. (34 in all) presently accepted by the author, annotated with geographic distributions. Six spp. are alleged to occur Costa Rica (with another, that we shall henceforth ignore, “maybe” present), as opposed to just two in the Manual treatment authored by Robert L. Dressler (JBL). As if that were not enough, one of the names used in the Manual, Cycnoches amparoanum Schltr., does not even appear on the list, being effectively relegated (along with C. pauciflorum Schltr., its synonym according to the Manual) to nomen dubium status. That leaves Cycnoches warscewiczii Rchb. f., plus the following: C. aureum Lindl. & Paxton, C. guttulatum Schltr., C. pachydactylon Schltr., C. rossianum Rolfe, and C. stenodactylon Schltr. Of the five last-mentioned names, only C. guttulatum is even mentioned in the Manual, as having been attributed to Costa Rica on the basis of a cultivated specimen of dubious identity and provenance. Three of these names—C. guttulatum, C. pachydactylon, and C. stenodactylon—are based on Panamanian types and have been used for spp. reported from Nicaragua (all were treated fully in Flora de Nicaragua), so we ought to have at least discussed those spp. as potentially occurring in Costa Rica—or listed the names in synonymy, as the case may be. Interestingly, all three of those names were used for spp. accepted in Dressler’s (1993) Field guide to the orchids of Costa Rica and Panama, along with C. aureum, the geographic range of which was purported to include Costa Rica. The last-mentioned sp. is the only one not treated in the Manual for which we have been able to locate a bona fide Costa Rican herbarium voucher: Holm & Iltis 105 (MO), from near Turrialba, determined in 2007 by Gustavo Romero (AMES) and Günter Gerlach (M); however, we have no idea whether this represents an addition to the flora or simply a different usage of names (C. aureum being older than C. amparoanum). As we have emphasized in the past, the taxonomy of many of these horticultural orchid genera has been erected largely on the basis of observations (by hobbyists) involving relatively few and widely scattered specimens in cultivation, often of unknown or dubious provenance, rather than careful herbarium work and field studies (by biologists) involving wild populations. Thus, geographic distributions tend to be weakly documented and sp. circumscriptions (not to mention the application of names) suspect as well as highly variable. The remainder of this paper deals mainly with taxonomic history and the characterization of infrageneric taxa or sp. complexes, making liberal use of illustrations, tables, and (sometimes) short keys. The supplement in which it appears is dedicated to the genus Cycnoches, with a companion paper devoted to horticultural aspects.
Clark, J. L., M. M. Funke, A. M. Duffy & J. F. Smith. 2012. Phylogeny of a Neotropical clade in the Gesneriaceae: more tales of convergent evolution. Int. J. Pl. Sci. 173: 894–916.
Six genera are revealed as para- or polyphyletic in this molecular study, including the following five that are represented in Costa Rica: Codonanthe, Episcia, Nautilocalyx, Neomortonia, and Paradrymonia. We were aware of the suspicions regarding Neomortonia (see the discussion under that genus in the Manual), but the rest of this comes as a surprise. Maybe not such a big one in the case of the similar and weakly separated Nautilocalyx and Paradrymonia, both of which appear to be polyphyletic, with chunks of Nautilocalyx—together with a monophyletic Chrysothemis—nested in the main Paradrymonia clade. Whether to recognize “a single large genus” (Chrysothemis being the oldest name) or “to divide Paradrymonia and Nautilocalyx into multiple genera” cannot be decided without “greater species sampling,” currently underway. Codonanthe is diphyletic and nested (together with the South American Codonanthopsis) among spp. of the South American genus Nematanthus (which has the oldest name in the group); the need for “further sampling” is also invoked in this situation. The diphyly of Episcia will likely have no impact on Costa Rican floristics, with E. lilacina Hanst., our only native sp., apparently grouping with the generic type. Neomortonia nummularia (Hanst.) Wiehler and N. rosea Wiehler (both of which occur in Costa Rica) emerge as quite widely separated, demolishing the original concept of this oliogspecific genus; “there is strong support for N. rosea as sister to Drymonia…and for N. nummularia as sister to” the clade that includes Alloplectus, Columnea, Drymonia, and Glossoloma. So Neomortonia nummularia clearly merits separate generic status, but as luck would have it, the genus name is attached to N. rosea “meaning that a new generic name is necessary for N. nummularia” (it is not supplied here). Other incidental implications of this research: the separation of Alsobia from Episcia (as per Ricardo Kriebel’s Manual treatment) is upheld; also supported is the concept (implemented in the Manual) of Columnea as a single genus, rather than the five (Bucinellina, Columnea s. str., Dalbergaria, Pentadenia, and Trichantha) envisioned by the late family specialist Hans Wiehler; and a sister-group relationship of Oerstedina and Rufodorsia is “strongly supported” although, contrary to the Manual, these authors tentatively retain Oerstedina as a separate genus pending “future phylogenetic and monographic work.”
Fernández Campos, M. 2011. Reconsideración de Trichosalpinx minutipetala (Ames & C. Schweinf.) Luer (Orchidaceae: Pleurothallidinae)/A reconsideration of Trichosalpinx minutipetala (Ames & C. Schweinf.) Luer (Orchidaceae: Pleurothallidinae). Orquideología 28: 119–134.
The sp. named (twice) in the title, listed as a synonym of Trichosalpinx memor (Rchb. f.) Luer in the Manual treatment of Trichosalpinx by Carlyle Luer (2003), is liberated from from said servitude. Both spp. are provided with amended descriptions and compared meticulously in a tabular format, the numerous differences involving the ramicauls, leaves, inflorescences, calyx, and corolla. Both spp. are also featured in a distribution map and separate composite line drawings, though only Trichosalpinx minutipetala is accorded specimen citations, distribution and phenology summaries, and color photos of living and type material. Based on the specimen citations, T. minutipetala is endemic to Costa Rica (i.e., we gain an endemic sp. in this transaction), where it occurs at ca. 1450–2000 m elevation on the Atlantic slope of the Cordilleras de Tilarán and Central and the northern Cordillera de Talamanca, as well as on the Pacific slope of the eastern Cordillera de Talamanca (numerous collections are cited, with only the type having been garnered by anyone outside of the usual JBL clique). The Costa Rican range of the newly reimagined T. memor is not specified, except on the range map. As has been the bad habit of this journal, the article is published in both Spanish and English, in otherwise nearly identical versions.
Gibbons, K. L., M. J. Henwood & B. J. Conn. 2012. Phylogenetic relationships in Loganieae (Loganiaceae) inferred from nuclear ribosomal and chloroplast DNA sequence data. Austral. Syst. Bot. 25: 331–340.
Mitreola is polyphyletic (something always is). The resolution affects only an Australian endemic sp., which “warrants recognition as a new, monotypic genus” (no name is yet provided). The pantropical Mitreola petiolata (J. F. Gmel.) Torr. & A. Gray, the only member of the genus to reach Costa Rica, is the type sp. and safe for the time being.
Gravendeel, B. & J. Kruizinga. 2012. Orchideeënuitwisseling met Costa Rica: nieuwe soorten ontdekken in de 21ste eeuw. Orchideeën 74: 114–117.
Those are not typos in our citation: evidently it is possible to have three consecutive e’s in Dutch (the language of this paper and journal, and one which has occasionally been considered incomprehensible by its own native speakers). Of course, we are able to read very little of this article, but we gather (mainly from the numerous color photos) that it comprises a brief account of an orchid-biased trip to Costa Rica that included a trek to the once-remote Valle del Silencio (high on the Caribbean slope of the eastern Cordillera de Talamanca) and a visit to the Jardín Botánico Lankester (with several of its leading reserachers featured in the photos). The authors would seem to have a preference for subtribe Pleurothallidinae (especially the genus Lepanthes), at least for picture-taking purposes.
He, L.-J. & X.-C. Zhang. 2012.
Exploring generic delimitation within the fern family Thelypteridaceae. Molec. Phylogen. Evol. 65: 757–764.
Whereas contemporary New World authorities (led by Alan R. Smith) have tended to interpret the genus Thelypteris as coextensive with Thelypteridaceae, or (as in Flora mesoamericana Vol. 1) to split off only the oligospecific Macrothelypteris, Old World specialists (especially Ren Chang Ching and Richard Holttum) have recognized numerous additional segregate genera. The cladograms generated by the present research suggest (to us) that, if more than one genus is to be accepted in Thelypteridaceae, there must be at least three. Based on their resolution of “six distinct clades…with strong support,” these authors promote the recognition of at least nine genera, with “limited sampling” preventing “a final conclusion on the generic delimitation” of one of the clades; thus eight genera are firmly conceived. How would this novel classification (not yet formally implemented) translate to the system of two genera—Macrothelypteris and Thelypteris, the latter with six subgenera—utilized in Flora mesoamericana? The details are still somewhat hazy, but we can glean the following: Macrothelypteris is monophyletic and remains intact, but Mesoamerican Thelypteris decays into at least three separate genera, none of which bears the name Thelypteris. The largest chunk of Mesoamerican Thelypteris s. l. would be assigned to the genus Cyclosorus, which “is the most complicated group in this family and includes almost 600 species.” Cyclosorus would include subgenera Cyclosorus (Link) C. V. Morton, Goniopteris (C. Presl) Duek, Meniscium (Schreb.) C. F. Reed, and Steiropteris (C. Chr.) K. Iwats. of Flora mesoamericana. The second-largest bloc of spp. assigned to Thelypteris in Flora mesoamericana, comprising subgen. Amauropelta (Kunze) A. R. Sm., belongs to the clade that remains unresolved (although Amauropelta itself is “not supported as monophyletic”); the number of genera to be recognized in our region and the name or names to be deployed are yet to be determined. Finally, Thelypteris subgen. Stegnogramma (Blume) C. F. Reed, with only T. pilosa (M. Martens & Galeotti) Crawford occurring in the Mesoamerican region (apparently including Costa Rica, contrary to Flora mesoamericana), would assume the rank of genus. The five other genera recognized in this study—Cyclogramma, Oreopteris, Phegopteris, Pseudophegopteris, and Thelypteris s. str.—are evidently north-temperate and/or Old World entities that do not reach Meosamerica. It bears mentioning that, cladistically speaking, the results of this investigation present no obstacle to a return to the all-inclusive Thelypteris favored by Smith in Robert G. Stolze’s Ferns and fern allies of Guatemala (1981).
Kok, R. de. 2012. A revision of the genus Gmelina (Lamiaceae). Kew Bull. 67: 293–329.
The genus Gmelina, which “occurs naturally from India and South China to North Australia and Fiji,” will be treated the Manual (under Verbenaceae) only because one of its spp., G. arborea Roxb. ex Sm., is cultivated on plantation scale in Costa Rica. Three additional spp.—Gmelina asiatica L., G. elliptica Sm., and G. philippinensis Cham.—are supposedly planted throughout the tropics as ornamentals, but we have not found a single Costa Rican record for any of these. Thus, this revision (which, in any case, does not cite cultivated material) is of limited use to us. The 31 spp. accepted by the author are distinguished in a dichotomous (but non-indented) key, and the spp. entries are sequenced alphabetically, with no infrageneric classification employed. Synonymy, typology, technical descriptions, and distribution summaries are provided at all ranks, along with specimen citations and indications of conservation status, phenology, uses, and vernacular names for the infrageneric taxa. Also included are distribution maps and sections on “Dubious taxa” and “Excluded species”; however, there are no indices. The brief introductory part addresses taxonomic history, uses, and morphology. Three spp. (none of interest to us) are described as new, and these alone are illustrated (with composite line drawings).
Li, F.-W., K. M. Pryer & M. D. Windham. 2012.
Gaga, a new fern genus segregated from Cheilanthes (Pteridaceae). Syst. Bot. 37: 845–860.
Anyone with even a smattering of knowledge about ferns is aware that the so-called “cheilanthoids” are a mess, and have a tumultuous taxonomic history. The pivotal genus Cheilanthes, in particular, “is notorious for its lack of morphological distinctiveness and its constantly changing circumscription.” As noted by these authors, “recent phylogenetic studies have documented the extensive polyphyly of Cheilanthes s. l., with species traditionally assigned to this genus appearing in every major clade of cheilanthoid ferns.” Their research focuses on a monophyletic group of spp. known informally as the “Cheilanthes marginata group,” which is sister to the oligospecific North American genus Aspidotis. The authors decline to combine the C. marginata group with Aspidotis, because the latter is “a relatively distinct and morphologically cohesive group”; they also eschew the option of lumping everything into Cheilanthes, “because the resultant clade also encompasses the genus Hemionitis, which has priority over Cheilanthes.” They decide instead to recognize the C. marginata group as the new genus named in the title, even though, by their own admission, said genus “is nearly impossible to distinguish from Cheilanthes s. l.” and “the recircumscription of Cheilanthes is a work in progress.” Yes, the new genus honors Lady Gaga (don’t get us started), but there is a clever corollary: all of its spp. have “GAGA” at nucleotide positions 598–601 in the matK gene alignment, “a sequence pattern not seen at this site in any other cheilanthoid fern sampled” (we’re betting they had to search long and hard for this tidbit!). The authors recognize 19 spp. of Gaga (although this is not a revision), ranging from Mexico (“the center of species diversity for the genus”) to Bolivia. The genus is formally described and its spp. enumerated (though not keyed), with synonymy and typology for all. Seventeen new combinations are validated and two new spp. are described, all in the names of “Fay-Wei Li & Windham.” Species of Gaga occurring in Costa Rica include the former Cheilanthes angustifolia Kunth, C. cuneata Link, C. harrisii Maxon, C. hirsuta Link, C. kaulfussii Kunze, C. marginata Kunth, and C. membranacea (Davenp.) Maxon. Also, one of the new spp. is a Costa Rican endemic: Gaga germanotta, most similar to G. marginata and ostensibly of hybrid origin, is restricted to páramo habitats at 3200–3350 m elevation in the Cordillera de Talamanca (the epithet replicates the surname of a well-known singer, ostensibly in honor of her parents). It is illustrated with a composite line drawing, and frond segments of selected additional spp. are similarly depicted. “Answers to the mysteries of Gaga have just begun to unfold,” observe the authors with giddy optimism. But considering early feedback from the taxonomic community, we wonder whether the very existence of the name may bias future authors toward an all-encompassing Cheilanthes.
O’Leary, N., S. S. Denham, F. Salimena & M. E. Múlgura. 2012. Species delimitation in Lippia section Goniostachyum (Verbenaceae) using the phylogenetic species concept. Bot. J. Linn. Soc. 170: 197–219.
Lippia section Goniostachyum Schauer is uniquely characterized within its genus by “bearing numerous florescences in each leaf axil and tetrastichous floral bracts” as well as by “the presence of fused florescence apical bracts.” The section was established with 18 spp., but had come to include 41 recognized “taxa” by the onset of this project. Employing the methodology (population aggregation analysis) and philosophy (phylogenetic species concept) advocated by palm specialist Andrew Henderson (NY) and others [see, e.g., The Cutting Edge 12(2): 8–9, Apr. 2005], these authors discriminate four “groups” in sect. Goniostachyum, each of which is accorded the rank of sp. (with two vars. being recognized for one of these). Because the section is largely South American, the taxonomic and nomenclatural impacts for Costa Rica are minimal and boil down to this: the sp. we have hitherto known as Lippia graveolens Kunth, which is native in Costa Rica and also cultivated as the principal source of culinary orégano, becomes Lippia origanoides Kunth. In fact, even this change is arbitrary, as the two names in question have equal priority; noting that “the name L. graveolens has been frequently used for Mesoamerican specimens, whereas the name L. origanoides has been frequently used in South American floras,” the authors—all South Americans, or at least based in South America—choose the latter name for the sp., ostensibly because “it reflects its typical aromatic nature” (what do they suppose graveolens means?). Features a dichotomous key to spp. and vars., synonymy, typology, descriptions, and distribution summaries at all ranks (including sect.), discussions of varying length, representative specimen citations, range maps, and sections on doubtful and excluded taxa. One new combination is validated at varietal rank, and numerous names are lecto- or neotypified. Each sp. and var. is depicted in a composite line drawing. The introductory part focuses on taxonomic history and the authors’ process of sp. delimitation.
Pérez-Escobar, Ó. A., E. Parra-Sánchez, M. Kolanowska & P. Ortiz V. 2011. Primer reporte de Telipogon lankesteri Ames (Orchidaceae) para Colombia. Orquideología 28: 36–40.
Telipogon lankesteri was anointed as a Costa Rican endemic in the Manual Orchidaceae account (2003), where it was treated under the mythical name “Stellilabium lankesteri (Ames) L. O. Williams” (see under “Annotate Your Copy”). Its discovery in Colombia (Valle del Cauca) means that we lose another endemic sp., but it seems we may already have lost this one some time ago, when T. lankesteri was relegated to synonymy under T. jostii (Dodson) N. H. Williams & Dressler (based on an Ecuadorian type) in a paper reviewed in these pages [see The Cutting Edge 13(2): 16, Apr. 2006]—though this particular detail was overlooked in our review.
Pruesapan, K., I. R. H. Telford, J. J. Bruhl & P. C. van Welzen. 2012. Phylogeny and proposed circumscription of Breynia, Sauropus and Synostemon (Phyllanthaceae), based on chloroplast and nuclear DNA sequences. Austral. Syst. Bot. 25: 313–330.
We thought the door had finally been slammed on this issue with the rectification [see under “Chakrabarty,” this column, in our last issue] of the authority citation of a new combination in Phyllanthus for the sp. previously known as Sauropus androgynus (L.) Merr. (sparingly cultivated in Costa Rica). But, as Lee Corso would say, not so fast…we should have expected that the splitting option would rear its head, and it has wasted no time in doing so. Criticizing a previous study [see The Cutting Edge 13(3): 8, Jul. 2006] as having employed “very poor…and very uneven” sampling, the present authors sought to “increase the phylogenetic resolution” of Phyllanthus s. l. through “increased sampling of species.” Be that as it may, their results are grossly similar: all the genera mentioned in the title are nested within Phyllanthus s str. Where these authors differ is in their philosophy of classification: they are splitters rather than lumpers, arguing that to unite everything in Phyllanthus would create an “unwieldy genus without distinctive characters” (a subjective judgment we are apparently expected to accept on faith), while moving “the delimitation problem to the infrageneric level” (where it belongs, we would maintain), “a level far less used in floras and other related research fields such as ecology” (where technical distinctions of minor taxa serve no useful purpose). So what is their “proposed circumscription” of the study group? See our review of a pevious paper by this same group [The Cutting Edge 16(2): 9, Apr. 2009]; the song remains the same, and still no formal nomenclatural changes have been implemented.
Silvera, K. & G. A. Silvera. 2012. Encyclia chloroleuca (Orchidaceae: Laeliinae) reported for Panama. Kew Bull. 67: 499–501.
We cite this paper mainly for Table 1, summarizing explicitly the purported differences between Encyclia chloroleuca (Hook.) Neumann, E. amanda (Ames) Dressler, and two other spp. Although E. amanda apparently has not been found in Costa Rica, it could turn up there (the type having been collected in Panama); the name has been misapplied to Costa Rican material of E. chloroleuca, and has been tentatively proposed as a synonym of the latter name by some authors [see under “Pupulin,” this column, in The Cutting Edge 19(2), Apr. 2012].
Small, E. 2011. Alfalfa and relatives: evolution and classification of Medicago. NRC Research Press, Ottawa, Ontario, Canada. 727 pp.
Everything you ever wanted to know about Medicago (Fabaceae), a Eurasian genus with just three spp. cultivated or sparingly naturalized in Costa Rica, is certainly contained or at least referenced in this heavy volume, the culmination of the author’s lifetime of research on the taxon. Although there is some inevitable emphasis on agronomic aspects, particularly with regard to the economically important Medicago sativa L. (Alfalfa), this is in essence a taxonomic work. The author recognizes a total of 87 spp. for the genus (vs. “ca. 83” according to co-PI Nelson Zamora’s Manual treatment of Fabaceae), several of these having been transferred from Trigonella (which itself remains rather nebulously differentiated from Melilotus). The circumscription and typification of Medicago (now monophyletic, according to DNA evidence) are discussed, a formal (if brief) generic description is provided, excluded spp. are listed, and an infrageneric classification is presented that provisionally accepts 14 sections and 10 subsections, each briefly diagnosed. Dichotomous keys separate the genera of tribe Trifolieae, the sections of Medicago and (where necessary) their subsections, and (in a single, apparently artificial key) the spp. and infraspecific taxa, all but the last of these keys being indented. Separate keys to infraspecific taxa are also included (as needed) in the sp. accounts, which are ordered alphabetically except for that of M. sativa, placed at the head of the pack. While 63 pages are devoted to M. sativa, an average of about 5.4 pages (generous in its own right) is allotted to the remaining 86 spp. Each sp. account features a description and identification hints, representative collections, and illustrations (generally a composite line drawing or photograph of a type specimen), and addresses typification and synonymy, vernacular names, distribution, phenology, ecological (pollination, dispersal, etc.) and agronomic topics, chromosome number, genetic relationships, conservation status, and germplasm sources. At the end of the book are found a glossary and indices to synonyms, French and English common names, and cultivars. The introductory portion—richly illustrated with both photos (including 16 color plates) and drawings and with plenty of graphs, tables, and maps—elaborates upon the format for the sp. accounts and discusses the economic importance of Medicago, genetic resources, biogeography, chromosome evolution, interbreeding barriers, morphology, physiological adaptations, and coevolution with nitrogen-fixing bacteria. We expect this exemplary work to stand as the last word on Medicago for many decades to come.
N.B.: Interestingly, just one of the two Medicago spp. formally treated in the Manual, M. polymorpha L., is attributed in the book under review to Costa Rica, this on the basis of Khan et al. 560 (BM; from 1600 m near the Continental Divide in the Valle Central), a specimen that we have been ignorant of until now (a missing historical collection was cited in the Manual); on the other hand, Costa Rica is here omitted from the geographic distribution of M. arabica (L.) Huds., a modern collection of which was cited in the Manual. Likewise overlooked is Medicago sativa L., mentioned in the Manual genus discussion as rarely cultivated in Costa Rica (but with a recent specimen cited). Our readers may wish to amend the brief Manual characterization of M. sativa to read “fls. a menudo púpura” (it turns out that several infraspecific taxa can have yellow or yellow-variegated flowers).
Terra-Araujo, M. H., A. D. Faria, J. E. L. S. Ribeiro & U. Swenson. 2012. Flower biology and subspecies concepts in Micropholis guyanensis (Sapotaceae): evidence of ephemeral flowers in the family. Austral. Syst. Bot. 25: 295–303.
Previous workers have recognized three subspp. of Micropholis guyanensis (A. DC.) Pierre (one lacking a scientific name), all of which occur sympatrically in the Reserva Florestal Adolpho Ducke near Manaus, Brazil, where these studies were carried out. The authors conclusions are aptly summarized by the following statement in their Abstract: “We are not able to find any clear distributional or morphological discontinuities between the subspecies and we, therefore, suggest that M. guyanensis should be considered a variable species without formally recognised subspecies.” The subspp. had been distinguished on the basis of leaf dimensions and other laminar features, with Mesoamerican material assigned to the autonymic subsp.
Trias-Blasi, A., J. A. N. Parnell & T. R. Hodkinson. 2012. Multi-gene region phylogenetic analysis of the grape family (Vitaceae). Syst. Bot. 37: 941–950.
According to this study, the family Vitaceae is monophyletic (thankfully!), as is the genus Vitis, but both Ampelocissus and Cissus (the only other genera occurring in Costa Rica) are polyphyletic (possibly at least triphyletic, in each case). As we noted in our review of an earlier paper reporting substantially these same results [see The Cutting Edge 13(2): 13, Apr. 2006], nomenclatural consequences could ensue for the New World Ampelocissus spp. (just one of which occurs in Costa Rica); however, the Mesoamerican Cissus spp. (including 17 in Costa Rica) are probably safe, as they seem to belong to the “‘true Cissus’ clade,” presumably harboring the generic type (though it was not studied). The authors emphasize the need for a “wider representation” of taxa in order to resolve the classification of these groups.
Tyrrell, C. D., A. P. Santos-Gonçalves, X. Londoño & L. G. Clark. 2012. Molecular phylogeny of the arthrostylidioid bamboos (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) and new genus Didymogonyx. Molec. Phylogen. Evol. 65: 136–148.
Poaceae subtribe Arthrostylidiinae is demonstrated “confidently” as monophyletic, and the genera Elytrostachys and Merostachys also appear to meet that standard (with both the type and sole Costa Rican sp. of Elytrostachys featured in the study, but neither in the case of Merostachys). However, the future looks grim or at least highly uncertain for Aulonemia, Arthrostylidium, and Rhipidocladum, the only other genera in the group represented in Costa Rica, all of which appear to be at least triphyletic. Aulonemia patriae R. W. Pohl, the only one of the two Costa Rican members of that genus included in the study, groups with the generic type and ought to be safe. The same is true of Arthrostylidium venezuelae (Steud.) McClure, but A. merostachyoides R. W. Pohl and A. pubescens Rupr., the two other Costa Rican congeners sampled, are on shakier ground. All five Costa Rican spp. of Rhipidocladum were part of the study, but none groups with the generic type (which itself is very close to Arthrostylidium s. str.); four of the Costa Rican Rhipidocladum spp. group closely together, the outlier being R. maxonii (Hitchc.) McClure, paired with Arthrostylidium merostachyoides in a strongly supported (though weakly characterized) clade that is sister to Elytrostachys. The authors note that “Arthrostylidium has long been a taxonomic catch-all for aberrant neotropical woody bamboos,” and that “a number of the species currently classified as Arthrostylidium are morphological anomalies which may prove to be new genera or may not even belong in the subtribe.” They add that “the fate of Rhipidocladum is intimately tied to Arthrostylidium, and “this imbroglio cannot be sorted out without greater taxon sampling, in-depth morphological analysis, and sequencing of nuclear markers.” Thus taxonomic action on this group is largely deferred to future publications (some cited as “in preparation”), the sole exception being the segregation from Rhipidocladum of two South American spp. into the new genus of the title.
Wahlert, G. A. & H. E. Ballard, Jr. 2012. A phylogeny of Rinorea (Violaceae) inferred from plastid DNA sequences with an emphasis on the African and Malagasy species. Syst. Bot. 37: 964–973.
This study, “the first estimation of the phylogeny of Rinorea with sampling across its distribution and breadth of morphological diversity,” substantiates that one small group of spp., the so-called “Rinorea ‘Apiculata’ group, is sister to “Rinorea sensu stricto” (i.e., the rest of the genus). Previous research had suggested that Rinorea, a pantropical genus of ca. 250 spp., is not monophyletic, since “Rinorea sensu stricto” is sister to the “remaining Violaceae” (except Fusispermum, which isbasal to everything else). The present authors (the second of whom is the Manual Violaceae contributor) therefore speculate that the Rinorea ‘Apiculata’ group “might best be treated in a segregate genus.” The ‘Apiculata’ group comprises just three spp., of which only Rinorea crenata S. F. Blake occurs in Costa Rica.