Stelis zootrophionoides (Orchidaceae: Pleurothallidinae), a New Species from Mexico

Background

Stelis (Orchidaceae) encompasses approximately 1100 species of epiphytic orchids distributed throughout the Neotropics, with the highest diversity in Andean South America. Sixty-two species were recorded previously in Mexico.

Methods

We formally describe here Stelis zootrophionoides as a new species from Chiapas, Mexico. To determine its systematic position, we conducted a morphological comparison with other members of Pleurothallidinae and a phylogenetic analysis of nucleotide sequences from the plastid matK/trnK and trnL/trnF regions, as well as the nuclear ribosomal ITS region for 52 species of Pleurothallidinae. Sequences of 49 species were downloaded from GenBank and those of three species, including the new taxon, were newly generated for this work. The new species is described and illustrated; notes on its ecological preferences and a comparison with closely related species are presented.

Conclusions

The new species, known only from one location and apparently restricted to the cloud forest in the central highlands of Chiapas, Mexico, is considered a rare species. This small epiphyte is unique among the Mexican species of Stelis by the combination of dark purple flowers with the distal third of the dorsal sepal adhered to the apices of the lateral sepals, which are partially united into a bifid synsepal, leaving two lateral window-like openings, and sagittate labellum. Stelis jalapensis, known from southern Mexico and Guatemala, also has the apices of the sepals adhered to each other, but it is distinguished by its larger flowers with lanceolate, acute dorsal sepal, completely fused lateral sepals (i.e. the synsepal is not bifid), and oblong-elliptic labellum. The phylogenetic analysis shows that S. zootrophionoides is closely related to other Mexican Stelis and corroborates previous suggestions that fused sepal apices have arisen independently in different lineages of Pleurothallidinae.     

Croton campanulatus (Euphorbiaceae s.s.), a new species from the Brazilian Atlantic rain forest

Croton campanulatus, a new species from southeastern Brazil in the states of Minas Gerais and Rio de Janeiro, is here described and illustrated. Morphological data indicate that this species belongs to Croton section Cleodora based on its arborescent habit, pistillate flowers with imbricate sepals, reduced petals, and multifid styles that are fused at the base.     

Listera fugongensis (Orchidaceae), a new species from Yunnan, China

Listera fugongensis, a new species from Yunnan, China, is described and illustrated. The new species is probably related to Listera nipponica, but differs from it by having green flowers, petals slightly wider than lateral sepals, and a toothed lip with ciliate margins.     

Two new species of Sisymbrium (Brassicaceae) from coastal Peru

Two new species ofSisymbrium are described from the Department of Arequipa in south-western Peru. Both are annuals from the loma vegetation.Sisymbrium lactucoides has glabrous leaves with clasping bases and is very distinct.Sisymbrium ferreyrae is probably closest toS. llatasii, but it is a much smaller plant with petals and sepals of subequal length (vs. petals longer than sepals inS. llatasii).     

A new species of <Emphasis Type="Italic">Symplocos</Emphasis> (Symplocaceae) from the Itatiaia Plateau of Brazil

Symplocos minima, a new species of Symplocos section Hopea from the Itatiaia Plateau in the Atlantic Rain Forest biome of southeastern Brazil, is described and illustrated. This species is distinguished by its densely compact shrubby habit, ascending leaves, fasciculate inflorescences with several persistent bracts, corolla with five to six erect lobes, pistillate flowers with the disc not thickened along the margin, fruiting calyx lobes obscuring the disc, and seeds sub-orbicular in cross section. The new species is morphologically related to S. itatiaiae and S. pentandra, but can be differenciated from them mainly due to the tree habit and fruiting calyx lobes not obscuring the disc in S. itatiaiae and the pistillate flowers with a disc that is thickened along the margin in S. pentandra.     

Two new species of <Emphasis Type="Italic">Sloanea</Emphasis> (Elaeocarpaceae) from the Brazilian Atlantic Forest

Two new species of Sloanea are described and illustrated: S. fasciculata D. Samp. & V. C. Souza and S. hatschbachii D. Samp. & V. C. Souza. Both species are endemic to the Atlantic Forest states of Espírito Santo and Paraná in Brazil. S. fasciculata is similar to S. hirsuta (Schott) Planch. ex Benth., but has a fasciculate inflorescence and deeply-divided stigma. S. hatschbachii is similar to S. lasiocoma K. Schum. with regard to the morphology of the leaves, flowers and inflorescence, which is a frondose-bracteate raceme, but can be differentiated by the size of the style, the extension of the connective, and the length of the sepals.     

A new species and a new combination in Stelis (Pleurothallidinae-Orchidaceae) from South America

Stelis duckei, of the Crocodeilanthe group, is described from the state of Ceará, Brazil. The new species is morphologically similar to S. speciosa, but can be distinguished by its longer ramicauls, wider leaves, and obtuse lip with a ridge-like callus at the base. The new combination Stelis speciosa is also provided here.     

Two new species of Ophiocaryon (Sabiaceae) from South America

Ophiocaryon barnebyanum from the Serra da Neblina (Venezuelan-Brazilian border) andO. neillii from southern Ecuador are described and illustrated, and their morphological relationships with allied spcies are discussed.Ophiocaryon barnebyanum is morphologically similar toO. duckei, but it differs by its larger leaves, leaflets, petioles, petiolules, and inflorescences, the higher number of secondary veins, and the ciliate sepals.Ophiocaryon neillii is a small tree related toO. klugii but differs by its smaller leaflets, petiolules and inflorescences, fewer secondary veins, lanceolate-acuminate sepals, and orbicular staminodes. An updated key to the species ofOphiocaryon is provided.     

A new species of <Emphasis Type="Italic">Mentzelia</Emphasis> section <Emphasis Type="Italic">Bartonia</Emphasis> (Loasaceae) from the Grand Canyon,Arizona

Mentzelia hualapaiensis, a new species of Mentzelia sect. Bartonia, is described from the Grand Canyon region of Arizona. The new species is closely related to M. puberula, which is found west of M. hualapaiensis along the Colorado River, and to M. oreophila, M. polita, and M. tiehmii. It shares with these species a suffrutescent shoot system characterized by a subterranean, branching caudex, multiple annual branches, and similar leaves that have shallowly lobed or toothed to entire laminas. The flowers of M. hualapaiensis differ from those of its closest relatives in having cream-white, linear to narrowly spatulate petals and staminodes, characteristics that are convergent with those of the flowers of the Chihuahuan Desert species M. humilis.     

Flower morphology and relationships of Schefflera subintegra (Araliaceae,Apiales): an evolutionary step towards extreme floral polymery

Gross morphology and the development of flowers in Schefflera subintegra (Araliaceae) are examined. The floral groundplan of this species is found to be very similar to that of Tupidanthus calyptratus representing a case of most extreme floral polymery within Araliaceae. Schefflera subintegra differs from T. calyptratus with respect to a lower floral merism (19–43 versus 60–172 stamens and 15–33 versus 60–138 carpels respectively) and by transformation from polysymmetry to disymmetry of flower in the course of its development. Close relationships between S. subintegra, T. calyptratus, and Schefflera hemiepiphytica have been confirmed by phylogenetic analysis based on nuclear ribosomal internal transcribed spacer sequences. These species form a subclade within the Asian Schefflera clade, with T. calyptratus as a sister taxon to two other species. Apart from more or less pronounced floral polymery, the species of this subclade share calyx and corolla without any traits of individual sepals and petals, and also a massive calyptra. As these data suggest, the extremely polymerous flowers of Tupidanthus apparently evolved in two steps: (1) the saltational multiplication of floral elements together with a loss of individuality of sepals in the calyx and petals in the corolla and (2) further polymerization of androecium and gynoecium. Mutation(s) in CLAVATA‐like gene(s) are suggested as a possible mechanism of the saltation event. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 553–597.     

A new species of Ornithocephalus (Orchidaceae) from Panama

Ornithocephalus aristatus, a new species from Panama, is described and illustrated. Among the species of the genusOrnithocephalus, it can be distinguished by the nonresupinate flowers, the sepals each provided with a flexuous awn half as long as the sepal itself, the porrect petals with revolute margins, the hastate lip with triangular-ovate, crose lateral lobes, the linear, acute midlobe, conduplicate and subreflexed at apex, and the dise with a bilobed, obreniform callus provided with a conical tuft of stiff hairs. A key to the species ofOrnithocephalus from Panama is provided.     

Impatiens pterocaulis sp. nov. (Balsaminaceae) from Guangxi,China

Impatiens pterocaulis S. X. Yu et L. R. Zhang, a new species of the Balsaminaceae from Yancha, Longlin, Guangxi Region, is described and illustrated. This species is similar to I. wilsonii in having nearly white flowers, 4 lateral sepals and a racememos inflorescence, but differs by having winged stems, very short‐spurred lower sepal, yellowish flowers and an acuminate dorsal petal apex. Pollen characters and leaf epidermal micro‐characters of these two species were studied, and the results support that the two species should be kept separate.     

<Emphasis Type="Italic">Croton borbensis</Emphasis>, a new species of Euphorbiaceae from white sands of Amazonian Brazil

A new species of Euphorbiaceae, Croton borbensis, is described and illustrated from western Amazonian Brazil. It shares features similar to another white sand Amazonian species, C. dissectistipulatus, but differs in having leaves with a serrulate-glandulose margin, no evident stipules, staminate flowers with six stamens and glabrous pedicels, pistillate flowers with few, shortly stipitate glands on the calyx, and a glabrous ovary. Croton borbensis is tentatively placed in section Barhamia.     

Three new species,a new combination,and a neotypification in <Emphasis Type="Italic">Dahlstedtia</Emphasis> (Leguminosae,Millettieae, Papilionoideae) from South America

Three new species of Dahlstedtia, D. burkartii, D. dehiscens, and D. lewisiana, are described from South America, and their relationships with related species are discussed. Dahlstedtia burkartii, from Argentina, has pink flowers with standard straight, whereas D. dehiscens and D. lewisiana, both from Brazil, have purplish to lilac flowers with a reflexed standard petal. A new combination, Dahlstedtia peckoltii, is proposed based on Lonchocarpus peckoltii and a neotype is selected for the latter. Information about geographic distribution and phenology of the species is provided.     

<Emphasis Type="Italic">Colletoecema gabonensis</Emphasis>, a third species of an unusual African genus of Rubiaceae

As a result of ongoing studies of the Rubiaceae of Gabon, the new species Colletoecema gabonensis is here described and illustrated. It is endemic to Gabon, where it is the only species of the genus, and is so far only known from three collections from the Ogooué-Lolo and Ngounié provinces. The new species is morphologically intermediate between its two congeners, C. dewevrei (from Cameroon, Central African Republic, Republic of the Congo, DR Congo, and Angola) and C. magna (endemic to Cameroon). The new species agrees with C. dewevrei in having flowers with exserted anthers and style, but differs in its sessile flowers and fruits. In the latter characters, it resembles C. magna, from which it can be separated by its smaller fruits and leaves, and by its different floral morphology. An IUCN conservation assessment has been made and the species is provisionally assessed as Vulnerable, based on its restricted area of occupancy and the small number of known locations.     

Morphological studies on the genusClematis linn. VIII. Floral and inflorescence anatomy inClematis patens with eight-sepaled flowers

The vascular anatomy of inflorescence axes and flowers ofClematis patens have been studied. The species shows a unique behaviour of the vascular bundles in the transition node from vegetative stem to pedicel: stelar bundles increase in number from six to eight as they ascend through the transition node so that the number of vascular bundles coincides with that of sepals. In the pedicel stele the resulting eight bundles are disposed opposite to eight sepals. respectively; each sepal receives its vascular supply from the bundle facing it. Morphological and anatomical evidence suggests that the calyx of eight sepals in this species should be interpreted as having consisted originally of four pairs of opposite organs, rather than as having been derived secondarily through chorisis of sepals from a calyx of four sepals as seen in most other species ofClematis.     

New contributions to Goodyerinae and Dendrobiinae (Orchidaceae) in the flora of China

Eight new species from China, Cheirostylis chuxiongensis, C. yei, Myrmechis lingulata, M. longii, Bulbophyllum ximaense, B. xizangense, B. retusum and B. pulcherissimum, are described and illustrated. Cheirostylis chuxiongensis differs from C. thailandica by having 5–9 irregular and papillae-like calli on each side in the sac of the lip, epichile with entire lobes, petals narrowly obliquely obovate and an apex that is not recurved. Cheirostylis yei is easily distinguished from its relatives similar by having a long stem, pubescent ovary and sepals, epichile lobes with irregular and undulate margins, a subquadrate callus without teeth in the saccate hypochile. Myrmechis lingulata differs from M. chinensis by having a simple and lanceolate to ligulate lip, glabrous bracts and ovary, oblique and narrowly ovate petals. Myrmechis longii differs from M. pumila by having white-veined leaves, oblong-lanceolate epichile lobes, and viscidium attached to the middle of the caudicle. Bulbophyllum ximaense is easily distinguished from its relatives similar by having distant pseudobulbs, shorter scape, an inflorescence with 9–16 orange-red flowers, shorter lateral sepals with a long acuminate apex, incurved and tubular apical margins, a papillate lip disk and triangular-subulate stelidia. Bulbophyllum xizangense is easily distinguished from its relatives similar by having narrow lanceolate leaves, shorter inflorescence with 1–3 greenish-yellow flowers, falcate-ovoid lateral sepals, a lip with small lateral lobes and 3 keels at the base. Bulbophyllum retusum differs from B. spathulatum by having shorter inflorescence, peduncles with 2 tubular sheaths, dorsal sepals with a retuse apex, lateral sepals with lower edges that are connate to each other and free and divergent toward the apex, obovate petals with an acute or slightly retuse apex. Bulbophyllum pulcherissimum differs from B. lopalanthum by its 5-veined dorsal sepal, ovate-lanceolate lateral sepals, obliquely ovate-oblong petal, erose-toothed margins and obovate lip with a large, oblong basal callus, and an obtuse base. In addition, three species (Bulbophyllum frostii, B. raskotii and B. nematocaulon) are reported for the first time in China.     

THE FLORAL ANATOMY OF DIPTERONIA

Hall , Benedict A. (State U. of New York, Cortland.) The floral anatcmy of Dipteronia. Amer. Jour. Bot. 48(10): 918–924. Illus. 1961.—The floral morphology of Dipteronia sinensis closely resembles that of such species of Acer as A. pseudosieboldianum. Both these species share the following characters: (1) complete flowers; (2) functional unisexuality of staminate flowers, resulting from abortion of the pistil; (3) andromonoecious condition, the same tree bearing both perfect and functionally staminate flowers; (4) nectariferous disc, extrastaminal in position. The vascular anatomy of the 2 species, described in detail in this paper, differs only in minor ways, having similar traces supplying, respectively, perianth, androecium and gynoecium. The greatest difference between the 2 genera lies in the form of the mature fruit, which in Dipteronia has the wings of the samaras completely surrounding the seeds; yet in both genera the vascular skeleton of the fruit is essentially the same. There is a similar cohesion of the vascular traces of sepals and petals in both these species. Differences between these and certain other species of Acer such as A. negundo and A. carpinifolium, herein described, greatly exceed those between A. pseudosieboldianum and Dipteronia. The flowers of A. negundo, for example, have undergone extreme reduction from the presumed ancestral type, having no petals or disc and lacking either stamens or carpels. These facts support the inclusion of Dipteronia in the Aceraceae, but make questionable its status as a genus separate from Acer.     

Comparative floral development in Lardizabalaceae (Ranunculales)

Lardizabalaceae, one of seven families of Ranunculales, represent a monophyletic group. The family has functionally unisexual flowers with the organs in trimerous whorls, petaloid sepals and sometimes nectariferous petals. Among Ranunculales, Lardizabalaceae share several floral characters and climbing habit with Menispermaceae, but molecular analyses indicate that Circaeasteraceae and Lardizabalaceae form a strongly supported clade. Morphological and ontogenetic studies of flowers have proved to be a good complement to molecular data in clarifying relationships. Floral organogenesis has been studied in very few species of the family. This study investigates the comparative floral development of three species from three genera (Decaisnea, Akebia and Holboellia) of Lardizabalaceae using scanning electron microscopy. Flowers have a whorled phyllotaxis. Within each whorl, the organs are initiated either simultaneously or in a rapid spiral sequence. In Akebia, six sepals are initiated, but one to three sepals of the second whorl do not further develop. The presence of three sepals in Akebia is thus a developmentally secondary simplification. The petals (if present) are retarded in early developmental stages; stamens and petals are different in shape from the beginning of development. The retarded petals may not be derived from staminodes in Lardizabalaceae. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166 , 171–184.