STUDIES OF PACIFIC ISLAND PLANTS. XXVI. METROSIDEROS COLLINA (MYRTACEAE) AND ITS RELATIVES IN THE SOUTHERN PACIFIC

The genus Metrosideros (Myrtaceae) is an abundant and taxonomically confusing component of the vegetation throughout much of its range. In the southern Pacific, from the New Hebrides eastward to the Society and Tuamotu Islands, the genus is represented by one variable species, M. collina (J. R. & G. Forst.) A. Gray, in which three widespread varieties seem to merit recognition. An attempt is here made to clarify the nomenclature and inter-relationships of these varieties. Additionally, two local endemics are related to the M. collina group—M. gregoryi Christophersen in Samoa and M. ochrantha A. C. Sm. (sp. nov.) in Fiji.     

STUDIES OF PACIFIC ISLAND PLANTS. XXIX. BLEASDALEA AND RELATED GENERA OF PROTEACEAE

The genus Kermadecia (Proteaceae), originally described as endemic to New Caledonia, has been expanded in recent decades to include three species from the New Hebrides and Fiji. Specialists on the Proteaceae have suggested that the three Melanesian species were generically misplaced, and careful reexamination supports this viewpoint. It is now apparent that a distinct group within the subfamily Grevilleoideae is composed of the genera Euplassa (endemic to South America), Sleumerodendron (a monotypic New Caledonian genus), Gevuina (based on a single South American species but recently expanded to include two other species from Queensland and New Guinea), and the three questionable Melanesian species. A review of this cluster of taxa indicates that Gevuina should again be interpreted as restricted to South America and that the generic name Bleasdalea F. v. Muell. ex Domin should be adopted for a group of five species extending from Queensland and New Guinea to the New Hebrides and Fiji. The relationships of the four genera are discussed and within Bleasdalea four new combinations are proposed: B. bleasdalei (F. v. Muell.), B. ferruginea (A. C. Sm.), B. vitiensis (Turrill), and B. lutea (Guillaumin). Kermadecia, very distinct from the four genera under present consideration, is again interpreted as a New Caledonian endemic.     

荚莲属观赏植物资源的研究

荚蒾属(Viburnum)植物全世界约有200种,其中有许多种类可供观赏,但国内外仅有少数几种被开发利用。本文介绍了46种荚蒾属植物在中国的应用现状和分布,论述了中国的传统名花——琼花(Viburnum macrocephalum)的植物学性状、栽培变异和品种分类,探讨了琼花的分类学难题;发现并定名了‘大花琼花’(V.macroce-phalum f.keteleeri'Big Flower')新品种;有7种荚莲属植物具有与琼花相似的观赏价值,值得在园林中推广。     

SOME COMMENTS CONCERNING THE REDUCTION OF THE GENUS THYSANOSPERMUM TO COPTOSAPELTA (RUBIACEAE)

The monotypic genus Thysanospermum Champ. ex Bth. from the Far East is reduced to the Indo-Asiatic genus Coptosapelta. It is a marked example of the insufficient attention given to testing, emending, or revising old generic concepts which in the tropics are so often taken for granted from handbooks. It is suggested that large critical regional floras are most appropriate for curing this inadequacy which hampers progress in our understanding of both taxonomical insight and geographical distribution.     

THE GENUS TRAPANIA (NUDIBRANCHIA: GONIODORIDIDAE) IN THE INDO-WEST PACIFIC

Seven new species of the nudibranch genus Trapania Pruvot-Fol,1931 (Goniodorididae) are described from the Indo-West Pacificand an eighth species, T. japonica (Baba, 1935), originallydescribed from one preserved specimen from Japan, is redescribedfrom specimens collected in Hong Kong and tropical eastern Australia.Three of the new species are from temperate south-eastern Australiaand one from tropical eastern Australia. Two species are knownonly from Hong Kong and a third is recorded from the SudaneseRed Sea as well as Hong Kong. Only ten other species of Trapania have been described, sixof those from Europe, and one each from Brazil, California,Japan and New Zealand. The anatomy and external colour patternof these species is compared with that of the seven new species. (Received 12 December 1986;     

POLLEN STUDIES IN THE GENUS CORDIA (BORAGINACEAE)

The pollen of 40 species of Cordia L. was studied by light microscopy and scanning and transmission electron microscopy. Three major types were found, 3-porate with a reticulate sexine, 3-colpate to 3-colporoidate with a striatoreticulate sexine, and 3-colpate to 3-colporate with a spinulose sexine. These pollen types are correlated with significant differences in the inflorescence, flower, and fruit structures found in the sporophyte. The following revisions are suggested and discussed: that Cordia sect. Varronia P. Br. be elevated to generic status; that Cordia sebestena L. and a few close allies be treated as generically distinct; and that Cordia myxa L. be conserved as the lectotype for the genus, thus continuing a wide application of the epithet Cordia.     

GENETIC STRUCTURE AND EVOLUTION OF SPECIES IN THE MANGROVE GENUS AVICENNIA (AVICENNIACEAE) IN THE INDO-WEST PACIFIC

Allozyme variation in species of the mangrove genus Avicennia was screened in 25 populations collected from 22 locations in the Indo-West Pacific and eastern North America using 11 loci. Several fixed gene differences supported the specific status of Avicennia alba, A. integra, A. marina, and A. rumphiana from the Indo-West Pacific, and A. germinans from the Atlantic-East Pacific. The three varieties of A. marina, var. marina, var. eucalyptifolia, and van australasica, had higher genetic similarities (Nei's I) and no fixed gene differences, confirming their conspecific status. Strong genetic structuring was observed in A. marina, with sharp changes in gene frequencies at the geographical margins of varietal distributions. The occurrence of alleles found otherwise in only one variety, in only immediately adjacent populations of another variety, provided evidence of introgession between varieties. The varieties appear to have diverged recently in the Pleistocene and are apparently not of ancient Cretaceous origin, as suggested earlier. Despite evidence of high degrees of outcrossing, gene flow among populations was relatively low (N_em < 1–2), except where populations were geographically continuous, questioning assumptions that these widespread mangrove species achieve high levels of long-distance dispersal.     

海南鱼骨木属一新变种

小乔木,高8-11米,胸径14-22厘米,小枝具梭;叶革质,倒卵形或倒卵状椭圆形,长3.3-9.0厘米,宽2.6-5.0厘米,先端凸尖,基部阔楔形至楔形,甚下延,全缘,两面无毛,有光泽,侧脉通常每面4-5对,网状小脉不明显,叶柄甚短,托叶卵状披针形或狭长三角形,长约5毫米,花簇生干叶腋间,每束具花4-6朵,具总花梗,小花柄长6-8毫米,无毛,萼管倒圆锥形,长2.5毫米,顶端5-6裂,花冠白花,冠管圆筒形,长约2毫米,喉部被小柔毛,顶端5-6裂,裂片近长圆形,与冠管等长,花丝短,花药长圆形或线形,长约2毫米,子房2室,每室具胚珠1颗,花住突出,长6-7毫米,柱头粗厚,常2裂或微缺,核果近球形或椭圆形,长6-8毫米,直径5-7毫米,内有种子2 粒花期5-6月。