We report for the first time the complete mitochondrial genome of Sinopotamon xiushuiense, which is found to be 18,460 bp in length, and contains 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA), and 1 non-coding region known as the D-loop. In addition, the mitogenome has 18 intergenic regions ranging from 1 to 1221 bp in length. The complete mitogenome of S. xiushuiense is the longest among brachyurans reported in GenBank before November 2015, and its AT content is slightly lower than that in Geotholphusa dehaani. The mitogenome data provides a basis for further studies on population genetics and phylogenetics.

Magnoliaceae), a new species from the Mount Bawangling, Hainan Province, China, is described and illustrated. It is closely related to M. paenetalauma Dandy, but differs by being a smaller tree with fewer spathe scars, absence of pedicels, pubescent and more numerous tepals, white pubescent and more numerous stamens.

Woonyoungia septentrionalis (Dandy) Law is a dioecious species with unisexual flowers in Magnoliaceae. The floral morphology and structure of the species are conspicuously different from other species and are important to the study of floral phylogeny in this family. The floral anatomy and ontogeny were investigated to evaluate the systematic position of W. septentrionalis, using scanning electron microscopy and light microscopy. All of the floral organs are initiated acropetally and spirally. The carpels are of conduplicated type without the differentiation of stigma and style. The degenerated stamens in the female flowers have the same structures as the normal stamens at the earlier developmental stages, but they do not undergo successive development and eventually degenerate. The male floral apex was observed to have the remnants of carpels in a few investigated samples. As the bisexual flower features could be traced both in the male and female flowers in W. septentrionalis, it suggests that the flower sex in Magnoliaceae tends toward unisexual. As well as the unisexual flowers, the reduced tepals and carpels and concrescence of carpels conform to the specialized tendency in Magnoliaceae, which confirms the derived position of W. septentrionalis in this family. As the initiation pattern of floral parts of W. septentrionalis is very similar to other species in this family, it needs further investigation and especially comparison with species in Kmeria to evaluate the separation of Woonyoungia.

new species of M. sect. Micheliopsis (Magnoliaceae) from Yunnan, China, is described and illustrated. Notes are also presented on the pollen morphology, phenology, ecology and conservation status of the new species. The new species was found growing in the evergreen broad-leaved forest at altitudes of 1500Á1650 m a.s.l. in Faduo Xiang, Xichou County, Yunnan Province, China. It is closely related to M. figo Sprengel, but differs in its higher habit (up to 15 m), densely brown villose indumentum with straight hairs, larger narrowly elliptic or elliptic leaves (12Á29.5 )4.0Á8.5 cm), abaxially pale green outer 3 tepals, densely pubescent ellipsoidÁovoid gynoecia, and 2Á3 ovulate carpels.