Dorsal Sepal Research Articles

<p><strong><em>Bulbophyllum gedangense</em></strong><strong> (Orchidaceae, Epidendroideae, Malaxideae), a new species from Tibet, China</strong></p>

Bulbophyllum gedangense (Orchidaceae), a new species from Tibet, China, is described and illustrated. It is morphologically similar to B. psychoon and B. levinei, but differs from them by having longer scapes, smaller flowers, sepals subequal in length, ovate dorsal sepal with obtuse apex, obliquely triangular-ovate lateral sepals with acute apex, ovate petals with entire margins and rounded apex.

A new species of Eurystyles (Orchidaceae: Spiranthinae) from Costa Rica

Eurystyles comprises about 23 species ranging from Mexico to northern Argentina. Six species are recognized in Mexico and Central America and three in Costa Rica. A new species, named E. uxoris, is here described and illustrated based on Costa Rican material. The species is similar to Eurystyles auriculata and E. standleyi, however, it differs by the smaller plants up to 3 cm tall, smaller leaves of less than 1.6 cm long, flowers with brown dorsal sepal and brown lip apex, petals callose or thickened at apex, and a pandurate lip. Information about distribution, habitat, ecology, etymology and phenology of the newspecies is provided. An updated key to the Costa Rican species of Eurystyles is presented.

Orchidantha anthracina (Lowiaceae), a new species from Vietnam

Orchidantha anthracina (Lowiaceae), discovered at the south central coast of Vietnam, is described and illustrated, bringing the total number of species in the family to 26, of which four occur in Vietnam. The notes on distribution, habitat and etymology are given and a preliminary conservation assessment is provided. The species is compared with O. vietnamica, with which it shares flowers of similar size and colours, but from which it is readily distinguished by a narrow and strongly reflexed dorsal sepal and spreading lateral sepals, not supporting the labellum. Notes with additional comparison to all species with a similar arrangement of lateral sepals are also provided.

<p><strong><em>Corybas circinatus </em></strong><strong>(Orchidaceae), a new species from Palawan, the Philippines</strong></p>

Corybas circinatus, a new species of helmet orchid endemic to ultramafic habitats on the island of Palawan, Philippines, is hereby described and illustrated. This species is distinct in bearing a small glandular protuberance at the front of its pedicel, a 4-lobed entire labellum, and a distinctive strongly incurved dorsal sepal. The general colouration of the floral and vegetative parts is also highly characteristic, and the general lowland to mid-montane ecology of the species is unique amongst the known Philippines Corybas.

<p><strong><em>Dendrobium rubrostriatum</em></strong><strong>, A New Species of <em>Dendrobium</em> section <em>Aporum</em> from West Kalimantan, Indonesian Borneo</strong></p>

Dendrobium rubrostriatum (section Aporum) is described and illustrated from West Kalimantan, Indonesian Borneo. It is morphologically close to Dendrobium lobulatum, but differs in having strongly reflexed petals and dorsal sepal, linear-acute petals, a different shape lateral sepals, a mentum which is only 1.5 times longer than the column, lip that has a straight claw lacking an abrupt bend near the base, a different shape of lobules of mid-lobe, and the disc that has a glabrous callus that in the natural position considerably exceeds the column.

A new Stelis (Orchidaceae: Pleurothallidinae) from the Western Andes of Colombia

Stelis excentrica, a new species endemic to the Cauca slope of the western Andes, municipality of Cali, Valle del Cauca, Colombia, is described and illustrated. It was found in the northern part of the Farallones de Cali National Park, in the vicinity of the protected area “El Danubio” administered by the Cali mayoralty. Stelis excentrica is similar to Stelis gigantissima from Ecuador but differs in the ocher-green flowers (vs. dark purple), the reniform petals (vs. flabellate petals), subquadrate lip with a minute apicule (vs. subcuneate without apicule). Reaching up to 30.6 mm from the apex of the dorsal sepal to the apex of the lateral sepal, Stelis excentrica probably has the largest flowers reported in any member of Stelis subgen. Stelis. Its 60 cm long inflorescence is only rivaled by that of Stelis gigantissima. Ecological notes, in situ photographs, typus illustration, maps, and a composite plate are provided.
 Key Words: biggest flower, Farallones de Cali, Stelis gigantissima, taxonomy

The genus Platanthera (Orchidaceae) in New Guinea with description of Platanthera valkenburgii sp. nov.

ABSTRACT Platanthera Rich. is a genus of ca. 125 species with a predominantly Northern Hemisphere distribution. A recent monograph of the genus did not cite important material from New Guinea. On the island the genus is represented by species from the tropical section Mecosa (Blume) Kraenzl. of subgenus Platanthera, which are not widely represented in herbaria and each specimen has a high value for taxonomic research. Studied materials not cited in the revision of the genus are cited as additional examined specimens here. A list of species with taxonomic and nomenclatural decisions is provided as a summary of knowledge about the genus on the island. Five taxa of Platanthera are recorded in this work for the region of New Guinea. One new taxon, Platanthera valkenburgii S.Nowak, Efimov, Szlach. & Kolan., is described. illustrated, and a photograph of the holotype is provided. The new species is readily distinguished by its strongly thickened to keel-like mid vein of the floral bract and dorsal sepal, petals at least as wide or wider than they are long, and its distinctly dilated lip. A key to the New Guinea taxa is provided. Two lectotypes are designated and taxonomic problems within Platanthera klossii (Ridl.) Efimov are discussed; one new combination is made.

Molecular phylogeny of Hiptage (Malpighiaceae) reveals a new species from Southwest China.

Hiptage is an Asia-endemic genus of Malpighiaceae currently placed in the tetrapteroid clade, representing one of the seven inter-continent dispersions from New to Old World. A molecular phylogeny based on sequences of the internal transcribed spacer (ITS) region was recovered for the first time for the genus. Our results showed that the most recent common ancestor of Hiptage probably originated in the South Indo-China Peninsula and diversified in this region. Based on phylogenetic evidence and relevant morphological traits, we propose a new species; Hiptage incurvatum is characterised by mericarps with arcuate anterior lateral wings, two large glands on the dorsal sepals, and small glands on the remaining sepals. The new species is from Mt. Cangshan, Dali City (25°35'N, 100°02'E) in North Yunnan, Southwest China and is notable for its occurrence at high altitude, 1400 m (the highest distribution currently known for the genus). The implications of this unusual species for the dispersal and evolution of the genus are discussed.

<p><strong>A new species of <em>Phragmipedium</em> (Orchidaceae: Cypripedioideae) from Peru</strong></p>

A new species of Phragmipedium section Lorifolia, P. cabrejosii, is described and illustrated from Peru, and its affinities are discussed. It is mainly compared with P. caricinum, from which it is distinguished by the simple inflorescence, the elliptic dorsal sepal, that is apically white, the shorter, apically twisted pale yellow petals tinged with rose, and the ovate-subrhombic staminodial shield (vs. reniform).

Bulbophyllum reflexipetalum (Orchidaceae, Epidendroideae, Malaxideae), a new species from Xizang, China.

Bulbophyllum reflexipetalum, a new species from Motuo County, Southeast Xizang, China, is described and illustrated here. This new species belongs to Bulbophyllum sect. Umbellata Bentham & J. D. Hooker, and it is morphologically similar to B. umbellatum Lindley, B. guttulatum (J. D. Hooker) N. P. Balakrishnan and B. salweenensis X.H. Jin, but is distinguished from them by having reflexed petals, base of dorsal sepal with 1 dentate on each side, lip with significantly revolute margin, adaxially with dark brown spots or patches and one longitudinal groove.

Liparis popaensis (Orchidaceae), a new species from Myanmar

Liparis popaensis, a new species of Orchidaceae, is described from Popa Mountain National Park, central Myanmar. Liparis popaensis is morphologically similar to L. odorata but it differs from the latter by having oblong-lanceolate dorsal sepal, column with two triangular wings and lip with a pair of subconical and basally adjoining calli at its base. Identification key and colour photographs are provided. A preliminary conservation assessment according to the IUCN Red List Categories and Criteria is given for the new species.

Paphiopedilum erythroanthum, a new species of slipper orchid (Cypripedioideae, Orchidaceae) from China based on morphological and molecular data

A new species of Paphiopedilum (Orchidaceae) from Yunnan, China is described and illustrated based on examining morphological and molecular evidence. Morphological comparisons indicate that the new species P. erythroanthum is somewhat similar to P. henryanum, from which it differs by its shorter scape, larger and purple-red flower without purple spots, an obovate dorsal sepal, narrowly oblong petals with recurved apex and a cordate staminode. Molecular analyses of combined nuclear and plastid datasets (ITS and matK) indicate that P. erythroanthum is sister to P. notatisepalum, which has leaves with large yellow spots, a shorter scape, larger flower, white sepals and petals with large purple spots. The morphological and molecular evidence support the hypothesis that P. erythroanthum is a new species.

Bletilla guizhouensis (Orchidaceae; Epidendroideae), a new species from Guizhou China: evidence from morphological and molecular analyses

Bletilla guizhouensis (Coelogyninae, Epidendroideae, Orchidaceae), a new species from Guizhou, China, is described and illustrated in this study based on the morphological and molecular evidence. Based on the morphological comparison, B. guizhouensis is closely related to B. striata, but differs in having ovate-oblong floral bracts, oblong-elliptic dorsal sepal, lip broadly-obovate, lip mid-lobe subelliptic, and disk with 7 longitudinal lamellae. These features distinguish the new orchid from all other known species of Bletilla. Molecular analysis based on nuclear ribosomal ITS and plastid DNA sequence data indicate that B. guizhouensis is a new species.

Polystachya danielana (Orchidaceae: Polystachyinae), a new species from Kenya

Polystachya danielana, a new species from Kenya based on evidence from morphology and molecular phylogenetics is described and illustrated here. It is closely related to P. spatella and P. kermesina, but distinguished from these two species mainly by its pseudobulbs mostly arising from the nodes near the base of the previous growth with only a few from the middle or upper nodes, leaves narrowly oblong or narrowly obovate-lanceolate, 2–8 × 1–2 cm, bracts oblong, ca. 4 × 3 mm, apex emarginate with a caudate tip, ovary purple, dorsal sepal subovate, 5.0–7.0 × 3.0–4.5 mm, column ca. 2 mm long. Its position in P. sect. Superpositae is discussed.

Colour preferences of Tetragonula carbonaria Sm. stingless bees for colour morphs of the Australian native orchid Caladenia carnea.

Innate colour preferences promote the capacity of pollinators to find flowers, although currently there is a paucity of data on how preferences apply to real flowers. The Australian sugarbag bee (Tetragonula carbonaria Sm.) has innate preferences for colours, including UV-absorbing white. Sugarbag bees are pollinators of the terrestrial orchid Caladenia carnea R.Br., which has both white and pink morphs. In laboratory conditions, we tested flower-naïve bees with the white and pink flower morphs revealing a significant preference for the white morph, consistent with experiments using artificial stimuli. In experiments to understand how bees may select food-deceptive orchids following habituation to a particular colour morph, we observed a significant increase in choices towards novel white flowers. We also observed that the presence of a UV-reflecting dorsal sepal signal significantly increased bee choices compared to flowers that had the UV signal blocked. Our findings demonstrate that innate preference testing of insect pollinators with artificial stimuli is replicated in a biologically significant scenario with flowers. The findings also underscore how food-deceptive orchids can receive sufficient pollinator visits to ensure pollination by having different morphs that draw on the innate preferences of bees and their ability to make decisions in a complex ecological setting.

Molecular mechanism underlying pseudopeloria in Habenaria radiata (Orchidaceae).

Habenaria radiata (Orchidaceae) has two whorls of perianth, comprising three greenish sepals, two white petals and one lip (labellum). By contrast, the pseudopeloric (with a decreased degree of zygomorphy) mutant cultivar of H.radiata, 'Hishou', has changes in the identities of the dorsal sepal to a petaloid organ and the two ventral sepals to lip-like organs. Here, we isolated four DEFICIENS-like and two AGL6-like genes from H.radiata, and characterized their expression. Most of these genes revealed similar expression patterns in the wild type and in the 'Hishou' cultivar, except HrDEF-C3. The HrDEF-C3 gene was expressed in petals and lip in the wild type but was ectopically expressed in sepal, petals, lip, leaf, root and bulb in 'Hishou'. Sequence analysis of the HrDEF-C3 loci revealed that the 'Hishou' genome harbored two types of HrDEF-C3 genes: one identical to wild-type HrDEF-C3 and the other carrying a retrotransposon insertion in its promoter. Genetic linkage analysis of the progeny derived from an intraspecific cross between 'Hishou' and the wild type demonstrated that the mutant pseudopeloric trait was dominantly inherited and was linked to the HrDEF-C3 gene carrying the retrotransposon. These results indicate that the pseudopeloric phenotype is caused by retrotransposon insertion in the HrDEF-C3 promoter, resulting in the ectopic expression of HrDEF-C3. As the expression of HrAGL6-C2 was limited to lateral sepals and lip, the overlapping expression of HrDEF-C3 and HrAGL6-C2 is likely to be responsible for the sepal to lip-like identity in the lateral sepals of the 'Hishou' cultivar.

Two new species and new records of Platystele (Pleurothallidinae: Orchidaceae) from Los Cedros Reserve in Ecuador

Two new species of Platystele were discovered at the orchid-rich forest of Los Cedros Reserve at North-west Ecuador. Many species of orchids grow in these forests and some endemic to it. Platystele cedriensis is similar to P. rhinocera from which it differs in the horizontal to descending inflorescence and the three-veined dorsal sepal. Platystele decouxii presents flowers with a unique heart-shaped lip with a heart-shape depression in the blade of the lip. We warn that on-going mining activities and concessions put in risk these and other endemic species from Los Cedros Reserve.
 Key words: Carchi, Orchidaceae, Platystele cedriensis, Platystele decouxii, sympatric species

QTLs Location of Calyx-related Traits in Tetraploid Dendrobium

In order to identify QTL locus of calyx-related traits in Dendrobium, 190 F1 individuals derived from the crossbreed of tetraploid Dendrobium cultivars D. Mangosteen x D. Burana Pink No.2 were used as materials. Through three years observation of four characteristics of calyx (length of dorsal sepal, width of dorsal sepal, length of lateral sepal, width of lateral sepal), the QTL was located on the two genetic maps of parents which had been already constructed. The result showed that the four characteristics were quite different among the individuals of F1 generation, and the observed values of all the characteristics were all positive distribution, which was suitable for QTL analysis. Nine QTLs were detected on the maternal ‘D. Mangosteen’ genetic linkage map, including 1 QTL for dorsal sepal length, 3 QTLs for dorsal sepal width, 2 QTLs for lateral length and 3 QTLs for lateral width, with the genetic contribution rate ranging from 11.9% to 16.8%. Also, two tight linkage markers were acquired (M10E3-146, M8E8-284). A total of 6 QTLs were detected on the paternal ‘D. Burana Pink No.2’ linkage map, including 2 QTLs for dorsal sepal length, 1 QTL for dorsal sepal width, 2 QTLs for lateral length and 1 QTL for lateral width, with the genetic contribution rate ranging from 11.8% to 17.3%. This result of study could provide reference for Dendrobium molecular marker assisted breeding and precise location of correlation gene.

QTLs Location of Calyx-related Traits in Tetraploid <i>Dendrobium</i>

In order to identify QTL locus of calyx-related traits in Dendrobium, 190 F1 individuals derived from the crossbreed of tetraploid Dendrobium cultivars D. Mangosteen x D. Burana Pink No.2 were used as materials. Through three years observation of four characteristics of calyx (length of dorsal sepal, width of dorsal sepal, length of lateral sepal, width of lateral sepal), the QTL was located on the two genetic maps of parents which had been already constructed. The result showed that the four characteristics were quite different among the individuals of F1 generation, and the observed values of all the characteristics were all positive distribution, which was suitable for QTL analysis. Nine QTLs were detected on the maternal ‘D. Mangosteen’ genetic linkage map, including 1 QTL for dorsal sepal length, 3 QTLs for dorsal sepal width, 2 QTLs for lateral length and 3 QTLs for lateral width, with the genetic contribution rate ranging from 11.9% to 16.8%. Also, two tight linkage markers were acquired (M10E3-146, M8E8-284). A total of 6 QTLs were detected on the paternal ‘D. Burana Pink No.2’ linkage map, including 2 QTLs for dorsal sepal length, 1 QTL for dorsal sepal width, 2 QTLs for lateral length and 1 QTL for lateral width, with the genetic contribution rate ranging from 11.8% to 17.3%. This result of study could provide reference for Dendrobium molecular marker assisted breeding and precise location of correlation gene.

An unexpected visitor

Inside each long and narrow flower spur of the round-leaved orchid (Platanthera orbiculata), a little bit of sweet nectar lures insects. On July 9 at the Hubbard Brook Experimental Forest in New Hampshire, a geranium plume moth (Amblyptilia pica) was seen visiting a P orbiculata. The slender moth was first found embedded in the floral orifice. The moth then flew to a nearby flower and latched onto its dorsal sepal and column with spurred legs. The plume moth could have been pollinating the flower or merely stealing nectar, since several flowers showed signs of already being pollinated, such as swollen ovaries and missing pollinia (when a pollinator uses its long proboscis to extract a flower's nectar, pollen sticks to its eyes to ensure dispersal). Although there is no empirical evidence, it has been speculated that some noctuid moths are the pollinators of P orbiculata based on the size of their mouthparts. While plume moth species have been recorded as likely pollinators for a closely related orchid (Platanthera sparsiflora) that bears similar flowers, to date there has been no evidence to suggest that they could be pollinators for P orbiculata. Geranium plume moths are also known as flower and seed feeders of several horticultural plants. However, it is uncertain whether P orbiculata could be a larval host because the photographed moth appears to be male. So, is A pica a newfound pollinator, a nectar thief, or a seed predator of P orbiculata?