Zeylanidium (Podostemaceae) comprises ribbon-like and crustose-rooted species in Asia, of which Z. lichenoides sens. lat. is widely distributed in Sri Lanka, India, Myanmar and Thailand. This study was conducted to clarify its relationships. In the matK phylogenetic tree obtained, plants of Z. lichenoides from northern Thailand were far from Z. lichenoides sens. str. and are separated as a cryptic species, Z. tailichenoides sp. nov. Zeylanidium tailichenoides is characterized by a 1-locular ovary and is quite similar with Z. lichenoides sens. lat. in other characteristics. The remaining Z. lichenoides sens. lat. is divided into Z. lichenoides sens. str. and three populations that we refer to as Z. ‘lichenoides,’ although morphologically all five are hardly distinguishable. Zeylanidium tailichenoides and one population of Z. ‘lichenoides’ are related independently to the crustose species.
Picea × notha, described by Rehder in 1939, is thought to be a putative hybrid between pollen receptive P. glehnii and pollen donating P. jezoensis var. hondoensis; however, such hybrid is questionable because the distributions of P. glehnii and P. jezoensis var. hondoensis do not overlap naturally. Recently, a natural hybrid between P. glehnii and P. jezoensis var. jezoensis, which is morphologically similar to P. × notha, was genetically determined. Therefore, the goal of this study was to identify the parental species of P. × notha using maternally inherited mitochondrial (mt), paternally inherited chloroplast (cp), and biparentally inherited nuclear (n) DNA markers and to elucidate the similarity of P. × notha and natural hybrids occurring in Hokkaido. Genetic analyses indicated that P. × notha harbored P. glehnii mtDNA, P. jezoensis var. jezoensis or P. jezoensis var. hondoensis cpDNA, and P. glehnii and P. jezoensis var. jezoensis nDNA almost equally. This clearly indicated that P. × notha is an F1 hybrid between pollen receptive P. glehnii and pollen donating P. jezoensis var. jezoensis and that it is similar to natural hybrids found in Hokkaido. This is the first report to demonstrate the parental species of P. × notha and its natural distribution in Hokkaido, Japan.
In this paper, based on recent collections, we add three species of Podostemaceae to the flora of Thailand. First, Cladopus pierrei was newly recorded from Sa Kaeo Province, southeastern Thailand. Phylogenetic analysis showed that C. pierrei is a paraphyletic species, in which plants from Thailand have a sister relationship with C. doianus. The number of stamens of C. pierrei in Thailand and Laos varies between 1 and 2, i.e., 2 in one clade, 1 in another clade, and 1 or 2 in a third clade. Cladopus is characterized by variation in stamen number. Second is Hydrobryum chompuense sp. nov. collected in Phitsanulok Province, northern Thailand. Phylogenetically, it is sister to H. varium, but morphologically distinct in having 1-locular ovaries with the septum free from the ovary wall. The third, Thawatchaia laotica, which has been reported from northern Laos, was newly recorded from Chiang Mai Province, northern Thailand. As a result, 10 genera and 52 species of Podostemaceae occur in Thailand.
A new species, Chrysosplenium suzukaense, from the northern part of the Yoro Mountains and Suzuka Mountain Range, Central Honshu, Japan, is described. Chrysosplenium suzukaense belongs to ser. Macrostemon, and is most similar to C. fauriei in the C. fauriei group (C. fauriei, C. kiotense and C. nagasei) distributed on the Sea of Japan side of Japan. However, C. suzukaense differs from C. fauriei in always having four stamens opposite the calyx lobes (vs. eight stamens), and smaller stature and flowers. The distribution of C. suzukaense is nearer the Pacific Ocean side, but in an area of much snow in winter, showing climatic conditions similar to the Sea of Japan side. The rosette-like basal leaves retained until end of the flowering time in C. suzukaense and the C. fauriei group may be an adaptation to the Sea of Japan side environment, especially to a much snow. The chromosome number, representing the karyotype, of C. suzukaense was confirmed to be 2n=22, and similar to other members of the C. fauriei group.
A new species, Quercus trungkhanhensis Binh & Ngoc (Fagaceae), from Cao Vit Gibbon Conservation Area, northeastern Vietnam is described. It is morphologically similar to Q. engleriana Seemen and Q. marlipoensis Hu & Cheng in having scaly cupules and in the shape, texture and glabrescence of the leaves, but distinguished from the former particularly by the size and morphology of the fruits (acorns and cupules) and the latter by smaller leaves with fewer lateral veins. Quercus trungkhanhensis is also similar to Q. franchetii Skan in fruit morphology, but differs in having glabrescent leaves.
Here we describe a new variety of the mycoheterotrophic genus Lecanorchis, L. triloba J. J. Sm. var. clausa Suetsugu & Fukunaga, discovered during a botanical survey in Okinawa Island, Ryukyu Islands, Japan. The new variety resembles Lecanorchis triloba var. triloba due to its densely flowered rachis and small fruits. However, the new variety differs in that it has complete cleistogamous flowers and a nonrecurved and narrowly triangular midlobe of the lip.
We report three new localities of the mycoheterotrophic plant Sciaphila corniculata (Triuridaceae) from Ishigaki Island, Ryukyu Islands, Japan. Previously, S. corniculata was reported only from Kolombangara Island (Solomon Islands), Waigeo Island (New Guinea) and Obi and Aru islands (the Moluccas). We also update a description of its morphology, in particular on stylar characteristics based on new materials. A key to the Japanese species of Sciaphila based on total flower and stylar characteristics is also provided for easy identification of these rare mycoheterotrophic plants.