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ABSTRACTS of APG 55 (2) A New Foliose-rooted Genus of Podostemaceae from Thailand with a Note on Root Evolution MASAHIRO KATO, SATOSHI KOI and YOKO KITA Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan Based on comparative floral morphology, and supported by molecular phylogenetic data, the foliose-rooted Thawatchaia trilobata gen. et sp. nov. (subfamily Podostemoideae) is described from northern Thailand. Similarities and dissimilarities in vegetative and reproductive characters between Thawatchaia and related foliose-rooted Asian genera are discussed and the consequence of their bearing on generic recognition is noted. The marginal meristem, which gives rise to the foliose root, was probably established at the base of a lineage leading to Thawatchaia, Hanseniella and Hydrobryum. A key to the Asian foliose-rooted genera is provided. Nothapodytes amamianus (Icacinaceae), a New Species from the Ryukyu Islands
Musa voonii, a New Musa Species from Northern Borneo and Discussion of the Section Callimusa in Borneo A new wild banana species, Musa voonii HŠkkinen, is described and illustrated. The species is abundant in the Lawas area, Sarawak, East Malaysia and in isolated locations within a radius of 200 km from Lawas. Remarks on the sect. Callimusa in Borneo are presented. Cytotaxonomy of the Thelypteris japonica Complex (Thelypteridaceae) Cytological and morphological observations were carried out for the Thelypteris japonica complex. Diploids (2n = 62) show echinate perispores, stramineous stipes, and short hairs at pinnule margins (mean, 0.1-0.2 mm long), and prefer rocky areas, usually growing on rocks. Tetraploids (2n = 124) have membranous perispores and long hairs at pinnule margins (0.2-0.4 mm long), and grow on forest floors. The occurrence of triploids (2n = 93) characterized by abortive spores is also confirmed. Two type specimens belonging to this complex were examined and compared with cytological vouchers. As a result, we regard the diploids as T. musashiensis (stat. nov.), the tetraploids as T. japonica f. japonica (having castaneous stipes) and f. formosa (stat. nov., having stramineous stipes), and the triploids as a hybrid between T. japonica _ T. musashiensis. Morphological Variation and Classification of Nuphar with Special Reference to Populations in Central to Western Japan Morphological variation in 52 populations of Nuphar japonica DC., N. subintegerrima (Casp.) Makino, N. oguraensis Miki and unidentified intermediate plants were investigated during a revision of Nuphar (Nymphaeaceae) in Japan. The phenogram of cluster analysis based on 15 morphological characters revealed five cluster groups (A~E). Clusters A, C and E had some remarkable characters and corresponded well to the description of N. japonica, N. oguraensis and N. subintegerrima sensu stricto, respectively. In contrast, Clusters B and D showed intermediate values in most of their characters. It was concluded that the intermediate plants, which usually had been identified as N. subintegerrima, were not conspecific with N. subintegerrima s. s. and that there were two different intermediate groups in central to western Japan. Morphological relationships suggested that the two intermediate groups were of hybrid origin between N. japonica and N. oguraensis and between N. japonica and N. subintegerrima, respectively. Results from the present study proved that populations of N. subintegerrima s. s. are limited in number and distribution, and that the species is one of the most endangered plants in Japan. Germination Response of Seeds of Aconitum grossedentatum (Ranunculaceae) to Temperature and its Significance to the Expansion of the Distribution Germination response of seeds of Aconitum grossedentatum to temperature was analyzed and its significance to the distribution of the genus is discussed. The underdeveloped embryo in ripe seeds grew at constant temperatures of 5 and 10oC , but did not grow at a constant temperature of 0oC. Seeds at a constant 5oC germinated gradually, but did not germinate at a constant 10oC. At 10oC embryos became dormant after growing to about 2 mm in length. Stratification at 0oC of seeds incubated at a constant 10oC resulted in synchronous germination. The germination responses to temperature fit well the annual changes in temperature in the habitat of A. grossedentatum. It is presumed that seeds need a period of one and a half years for germination in nature. Response of the developing cotyledons to temperature in early spring may be a controlling factor in the spread of the species by seeds. Short Communication Intraspecific Sequence Variation of Chloroplast DNA among the Component Species of Evergreen Broad-leaved Forests in Japan II KYOKO AOKI1, TAMOTSU HATTORI2 and NORIAKI MURAKAMI1 1Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan; 2Division of Ecological Restoration, Museum of Nature and Human Activities, Hyogo, Sanda, 669-1546, Japan For a phylogeographic study of the lucidophyllous (evergreen broad-leaved) forests in Japan, we surveyed intraspecific chloroplast DNA variation in 20 component species in those forests. Intraspecific cpDNA variation was detected in three species of plants, Elaeagnus glabra, Myrsine seguinii, and Trachelospermum asiaticum. Unusual Flowering Shoots of Damnacanthus (Rubiaceae) The spine of Damnacanthus has been interpreted as a metamorphosed leaf or a lateral branch. There is a hypothesis that a pair of spines is modified inflorescence by the observation in which vegetative and reproductive branching units are comparable to each other. Our observations of various transitional forms between the spines and the pedicels in Damnacanthus agree with the hypothesis.
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