Resumen. Una nueva Masdevallia de los bosques nublados de Huánuco, Perú, es descrita e ilustrada. Se compara con las que son consideradas sus parientes más cercanas, las simpátricas Masdevallia fenestralis y Masdevallia fenestrellata, pero difiere de ambas por la falta de áreas transparentes cerca de la base de los sépalos, y por la presencia de distintivas crestas externas en los sépalos.

Abstract. A new Masdevallia from the cloud forests of Huanuco, Peru, is described and illustrated. It is mor- phologically similar to what is considered to be its closest relatives, the sympatric Masdevallia fenestralis and Masdevallia fenestrellata, but differs from both by the lack of translucent fenestrations (“window-like” areas) near the base of the sepals, and by the presence of distinct external ridges of the sepals.

Abstract A new species of Chiloschista from a restricted area in Bhutan is described and illustrated. It is featured with color photos and a map showing its only known locality. The new species is compared with the other three spotted Chiloschista species from Bhutan: C. densiflora, C. gelephuense, and C. himalaica, which have similarly colored flowers, but different lip structure and the differences are explained and illustrated.

Abstract A new small-flowered Cyrtochilum from Peru is described, illustrated with photos and drawings, and compared to similar species. The new species is similar to C. fidicularium and C. gracile in having extra thumb-like projections above the rounded ventral lobes of the column but differs from C. fidicularium by the more sharply pointed and forward projecting callus keels on the lip and by a longer front-lobe of the lip, versus blunt and downward directed lobes in C. fidicularium. The new species differs readily from Cyrtochilum gracile by the long and wiry inflorescence, versus a more sub-erect and straighter panicle in C. gracile.

Abstract A new and previously little-known Cyrtochilum (Orchidaceae: Oncidiinae), is named in honor and in memory of Leonore Bockemühl, who published a monographic treatment of Odontoglossum in 1989, which included many species that subsequently were transferred to Cyrtochilum based on molecular evidence. One of these species that was included in her treatment as ''Odontoglossum leucopterum'' is in fact an undescribed Cyr- tochilum and is described here. The real ''Odontoglossum leucopterum'', which was transferred to Cyrtochilum in 2001, has proven to be quite elusive since its original description. It was only recently photographed in the Sierra Nevada de Santa Marta in northern Colombia, its only known location, and photos of this rare orchid are featured here for the first time. The new Cyrtochilum is described, illustrated and compared with closely related Cyrtochilum species which are featured with line drawings and color photographs to illustrate the differences.

Abstract Two new spotted species of Chiloschista from Bhutan are described, illustrated, and compared with similar species. The second of the new species has been misidentified in previous publications as C. lunifera and C. parishii, and a comparison between the three is provided. It is also compared with C. glandulosa, which is a distinctly smaller-flowered species from the coastal area of southwestern India, and with C. javanica from Indonesia. The latter species and C. parishii are easily distinguished from both new species by having hairs on the backside and along the margins of the sepals and petals, as opposed to having virtually glabrous to indistinctly micro-pubescent sepals and petals for the new species. Although many spotted Chiloschista species are superficially similar, the differences can be better observed when studying the internal morphology of particularly the glandular callosity in the saccate lip. The morphological differences are often minute and difficult to describe in words, but are more easily recognized when compared with illustrations and photographs.

Abstract. A new small-flowered species of Cyrtochilum from the isolated range of the Condor mountains in Ecuador is described and illustrated with a line drawing and a photograph of the holotype. It shares morphological features with several different-looking groups of Cyrtochilum, such as the two generitypes of the genus: C. undulatum and C. flexuosum, as well as with plants in the C. myanthum complex. These groups are treated as three separate genera by some (Cyrtochilum, Trigonochilum and Dasyglossum, respectively), but the combination of morphological features seen in our new species brings the groups together into one polymorphic but genetically monophyletic genus.

Abstract A new and unusual-looking Cyrtochilum species is described, compared with the possibly closely related Cyrtochilum leucopterum and illustrated by drawings and a photograph of the holotype. It is distinguished from Cyrtochilum leucopterum by having an elongate basal portion of the lip with erect lateral lobes, and a trilobed front lamina with a glabrous, blunt and thickened bilobed lip callus, versus what appears to be more horizontally spreading lateral lip lobes, and a densely micro-pubescent apically multifid lip callus for the latter species. The new species also has some purported silica bodies of unknown significance visible in plant and flower parts, which are not present in C. leucopterum.

Abstract A new species of Chiloschista Lindl. from western Thailand is described and illustrated with a line drawing and photographs. It is compared with the sympatric C. parishii Seidenf., from which it differs in having larger flowers, which are 11-12 mm across versus 8-10 mm across for C. parishii. The new species also distinctly differs in having widely spreading rostellum lobes and a viscidium that is as broad as the length of the stipe, as opposed to downward directed rostellum lobes and a viscidium that is distinctly narrower than the length of the stipe for C. parishii. The same distinguishing features separate the new species from the similarly colored C. trudelii Seidenf., which has inward-directed rostellum lobes and a viscidium that is distinctly narrower than the length of the stipe.

Abstract A new golden yellow small-flowered species of Cyrtochilum is described and illustrated with a line drawing and photographs. It is compared with superficially similar species in the C. aureum complex, in which the new species differs by the lack of lacerate column wings typical for that group. It is distinguished from all other known small-flowered Cyrtochilum species by the golden yellow color in combination with the distinctly pandurate lip lamina where the front lobe is wider than the basal lobes combined.

Abstract Two species, originally described as Odontoglossum amphiglottis and Odontoglossum sodiroi are here transferred to Cyrtochilum (Orchidaceae: Oncidiinae), based on molecular data and morphological features, accompanied by brief discussions about their taxonomic background and natural history, and illustrated with line drawings and photographs. Both species were previously considered to be synonyms of C. ramosissimum by the author of this paper and others, due to limited access of type material. But recent field discoveries reveal that a much stouter growth habit and distinctly corymbose inflorescences distinguish O. amphiglottis from C. ramosissimum. In the case of O. sodiroi the smoothly rounded pair of basal lip calli, which are marginally covered externally by the ventral flanks of the column, distinguish this species from C. ramosissimum, which has more or less denticulate basal callus keels on the lip, and where the ventral columnar flanks are marginally placed between these keels.

Abstract A new small-flowered natural Odontoglossum hybrid from northwestern Ecuador is described and illustrated with a line drawing and a photograph. The novelty is compared with its sympatric parent species, Odontoglossum armatum and O. mirandum. The flower of the new natural hybrid has shorter erect lateral liplobes compared to those for O. mirandum, but distinctly longer erect lateral lip-lobes compared to those for O. armatum, which are basically lacking altogether. The taxonomic status of the variable O. mirandum is briefly discussed.

Abstract A new species of Chiloschista from a restricted area in Bhutan is described and illustrated. It is compared with C. parishii from Myanmar and Thailand, which has similarly colored flowers and from which it differs by the larger flowers, 15-18 mm versus 8-10 mm, and the lack ofa glandular and pubescent, erect and curved callus lobe inside the lip, which is generally seen in other similarly colored species of this genus.

Abstract A new species of Cyrtochilum from the Eastern Cordillera of Colombia is described and illustrated. The new species is most similar to the pink-flowered Cyrtochilum distans but is distinguished by its white and yellow-green flowers with spreading sepals and a pink lip with a basally yellow and apically white callus consisting of two parallel keels (vs. pink lateral sepals that are fused to about half or more of their length and a white callus consisting of two basal and two apical spreading keels).

Abstract A new, attractive and morphologically unique species of Spathoglottis is described, illustrated and compared with the most similar species. The new species is currently only known from two localities in southeastern Bhutan and differs distinctly from its closest relative, Spathoglottis hardingiana, by the glabrous pedicels, forward-curved acuminate apices of the petals, a yellow hypochile of the lip, two pairs of unequal callus “horns” and swellings, and a spirally coiled epichile of the lip, versus a densely pubescent inflorescence and pedicels, a pale purple hypochile, a single pair of erect and clavate, or“bubble-shaped”, callus swellings, and a projecting and narrowly triangular epichile of the lip for S. hardingiana.