A new species of Thinouia (Paullinieae, Sapindaceae) from the Amazon and its phylogenetic placement

Molecular and morphological evidence support a new species of RosaceaePrunus subg. Cerasus from Wuyishan National Park, southeast China

Prunustongmuensis, a new species of cherry blossom, is described and illustrated from Wuyishan National Park, southeast China. This species is characterized by its tubular to nearly bottle-shaped receptacles and dark purple drupes. It can be distinguished from other wild cherry trees by its flowers and leaves, reddish brown young leaves, presence of 1-2 glands at the base of leaves, petioles densely covered with yellowish brown villi, longer pedicels (0.6-2.5 cm), villous pistil, and dark purple drupes. In the present study, we conducted a comprehensive morphological study based on specimens of the new species and its morphologically close species, field observations, and examination of pollen morphology. In addition, our phylogenetic analysis based on the complete plastid genome sequences further confirms the status of the new species and indicates that it is closely related to Prunusclarofolia, however, it notably differs in leaf shape, size, petiole villus color, gland location, timing of flower and leaf openings, and reflexed or spread sepals, as well as drupe color.

Molecular phylogeny of Urvillea (Paullinieae, Sapindaceae) and its implications in stem vascular diversity

BACKGROUND AND AIMS

The tribe Paullinieae has the highest diversity of vascular variants among the seed plants. The developmental diversity is better understood in the species-rich genera Paullinia and Serjania; however, the phylogeny and diversity of vascular variants in the smaller genera of Paullinieae remain understudied. Here we investigate the evolution of development of stem vasculatures in the small genus Urvillea.

METHODS

We generate the first molecular phylogeny of Urvillea derived from 11 markers using a maximum likelihood and Bayesian approach. In combination with phylogenetic reconstruction, stochastic character mapping is used to assess evolutionary changes in stem ontogenies, determined from developmental anatomy of stems collected in the field or from herbarium and wood collections.

KEY RESULTS

Urvillea is supported as a monophyletic group and sister to Serjania. There are five stem ontogenies in Urvillea, including typical growth and four different vascular variants. Most stem ontogenies initiate with lobed stems in primary growth. Lobed stems in secondary growth are ancestral in Urvillea, but this ontogeny was lost multiple times. A reversal to typical growth occurred in non-climbing species. Phloem wedges, fissured stems, and ectopic cambia each evolved once independently. Phloem wedges is an intermediate developmental stage in the formation of fissured stems, which is characterized by a continuous fragmentation of vascular tissues. Lobed stems may generate constriction zones and lobes may split or not.

CONCLUSIONS

Urvillea is the third most diverse genus (after Serjania and Paullinia) with respect to the number of vascular variants within Paullinieae. One ontogeny (fissured stems) is exclusive to the genus. Differential cambial activity and ectopic cambia are the main ontogenetic processes generating stem diversity. The evolutionary history of vascular variants demonstrates the large developmental plasticity of the cambium in such a small genus and further demonstrates that complex anatomies have repeatedly evolved within Paullinieae lianas.

Paullinieae (Sapindaceae) of the restingas of Rio de Janeiro, Brazil: taxonomy and distribution

Abstract Paullinieae is a predominantly neotropical tribe comprising six genera (Cardiospermum, Lophostigma, Paullinia, Serjania, Thinouia and Urvillea), of which Lophostigma is the only one not found in Brazil. This study was conducted in the sandy coastal plains (restingas) of Rio de Janeiro state, which from the mouth of the Itabapoana river in the north, bordering Espírito Santo state, to Ponta da Trindade (including Ilha Grande) in the south, bordering São Paulo state. This ecosystem has great biodiversity, but has been constantly threatened by deforestation, human occupation and degradation resulting from tourism. In this area we found 30 species in five genera: Cardiospermum (1 sp.), Paullinia (9 spp.), Serjania (15), Thinouia (2) and Urvillea (3). The taxonomic treatment includes a key to identify the taxa, and for each species a morphological description, illustrations, a map of its geographical distribution, ecological information, phenological data, and conservation status. Most species occurred in ridge forests, followed by dune thicket and non-flooded scrub formations. Among of the 30 species, four (Paullinia coriacea, P. ternata, Serjania fluminensis and S. littoralis) were recorded only in the sandy coastal plains, and four are endemic to Rio de Janeiro state (Serjania eucardia, S. fluminensis, S. littoralis and S. tenuis). In addition, four species are already included in the Red List of Brazilian Flora and another three are indicated in this study as threatened. This research is important not only to improve knowledge of Paullinieae species found in Rio de Janeiro’s sandy coastal plains, but also to provide information to be used for conservation measures in the State, as well as in other coastal plains of Brazil.