NEW INTERPRETATION OF THE INFLORESCENCE OF FAGUS DRAWN FROM THE DEVELOPMENTAL STUDY OF FAGUS CRENATA,WITH DESCRIPTION OF AN EXTREMELY MONSTROUS CUPULE

The inflorescence of Fagus is generally considered to be a determinate one, i.e., an axillary dichasium, in contrast to those of most genera in the family, which are indeterminate, dichasial, or simple catkins. To understand the relationship between the two types, ontogenetic development of the inflorescence of Fagus crenata was investigated. The early developmental stages are similar in both the male and the female inflorescences. At first, the inflorescence is oval-shaped, then a swelling forms at the distal side of it. Subsequently, another swelling forms at the proximal side. The more or less conspicuous residual part of the primary inflorescence axis remains between the two swellings. The inflorescence becomes heart-shaped and the first flower forms at the summit of each swelling. Subsequently, higher-ordered flowers form dichasially in the male inflorescence, and the cupule valves differentiate in the female one. This organogenetic manner suggests that the inflorescence of Fagus is an indeterminate one, consisting of two dichasia arranged alternately on the primary axis. The scale leaves surrounding the inflorescence were also given a new interpretation. They were considered to be stipules of the bracts, because sometimes they constitute a continuous structure, together with an inconspicuous swelling between them. A proliferous-type monstrous cupule was interpreted as supporting evidence for the hypothesis.     

THE CRETACEOUS PTERIDOSPERMS RUFLORINIA AND KTALENIA AND IMPLICATIONS ON CUPULE AND CARPEL EVOLUTION

The vegetative (Ruflorinia sierra) and fertile (Ktalenia circularis) organs of an Early Cretaceous pteridosperm collected from Santa Cruz Province in Argentina are described. The sterile leaf is at least tripinnate and bears decurrent secondary pinnae with obliquely attached, sharply pointed pinnules. The fertile member arises from the base of the vegetative rachis and bears two types of appendages, cupules and bracts. Bracts are attached to the main axis near cupules and are present in clusters of up to six. Cupules are sessile, spherical, and arranged in opposite or subopposite pairs along the axis. A small lip is present on one surface of the cupule. The number of seeds per cupule may be one or two, with each characterized by a distal nucellar beak and circular, chalazal scar. Cuticular anatomy, including the fine structure of the stomatal complex, is described for both vegetative and reproductive organs. The cupules of Ktalenia and other Mesozoic seed plants are compared, and a discussion presented regarding the possible function of the cupule.     

Shoot development ofAucuba japonica I. Morphological study

The shoot development ofAucuba japonica was studied morphologically. The shoot shows dichasial branching in connection with the formation of a terminal inflorescence and shows a decussate phyllotaxis even in the reproductive phase. The sequence of initiation of successive foliar appendages is very precise, hence the foliage leaf, scale leaf and bract can be compared with each other even at their stages of initiation. In the stage of proximal foliage leaf formation the shoot apex is flat, while in the stage of formation of distal foliage leaves, bud scales and proximal bracts, it becomes concave. In the stage of formation of distal bracts the apex becomes domed. Plastochron durations are relatively long in the vegetative phase in comparison with other plants, and the duration from initiation of the first pair of appendages to that of the second is about one and a half months. Both male and female inflorescences exhibit basically a thyrsoid type of monotelic synflorescence.     

Ontogeny of pistillate flowers and inflorescences in Nothofagus subgenus Lophozonia (Nothofagaceae)

  Cupule and pistillate inflorescence morphology is described in detail for the first time for a number of species in Nothofagus subgenus Lophozonia. The architecture and temporal appearance of prophylls, flowers, and cupule valves is dichasial; the cupule valves are third and higher order shoot systems. Comparative studies demonstrate that the dorsal rows of appendages on the cupule valves have a similar arrangement, and each row exhibits the same temporal pattern of development. This suggests that the cupule valves in all species have a modular construction and consist of rows of homologous appendages. This study clearly demonstrates the uniform groundplan of the pistillate inflorescence in this subgenus. Received March 14, 2002; accepted May 8, 2002 Published online: September 13, 2002     

GLANDULAR STRUCTURES OF HOLOCARPHA AND THEIR ONTOGENY

Carlquist , Sherwin . (Rancho Santa Ana Botanic Garden, Claremont, California.) Glandular structures of Holocarpha and their ontogeny. Amer. Jour. Bot. 46(4): 300–308. Illus. 1959.—Two types of advanced glandular structures occur in the 4 species of the genus Holocarpha. Sessile disk-shaped glands occur at the tips of upper leaves and of involucral and receptacular bracts. Unlike all other glandular structures of Madinae which have been investigated, these originate from several protodermal initials rather than a single one. These glands, however, represent modifications of a glandular trichome. The other type of glandular structure, termed hollow-stalked trichome here, occurs on the outer surface of involucral and receptacular bracts. These trichomes originate from a single cell but differ from others in the formation of a hollow stalk, the wall of which is one cell in thickness. Mesophyll of the bract, often with an included vascular bundle, is present as an intrusion into the base of the hollow stalk. Corresponding to the advanced nature of the glandular structures, the leaves show specializations in the “inrolling” of margins. Upper leaves have a cylindrical organization of vascular tissue, whereas basal leaves are “normal” and leaves of the main stem are intermediate. The species of Holocarpha differ in certain details of leaf anatomy and structure of hollow-stalked trichomes. The systematic distribution of these is given. The essential unity of the various glandular structures of Madinae is discussed both in terms of mature structure and ontogeny, and the steps in the evolution of these are suggested.     

PSEUDOFAGUS IDAHOENSIS,N. GEN. ET SP. (FAGACEAE) FROM THE MIOCENE CLARKIA FLORA OF IDAHO

A new genus and species of Fagaceae are established for compressed leaves and attached fruits which represent one of the dominant taxa in the rich Miocene Clarkia flora of northern Idaho. The leaf and fruit morphology, cuticular and pericarp anatomy, and leaf phytoliths fall within the range of variation of the subfamily Fagoideae. The unique fruit consists of a large, exposed, distinctly keeled, trigonous nut and a diminutive basal cupule. The cupule has an apical frill of free, petiolate, leaflike appendages but lacks other ornamentation, and there is no evidence of a distinct Valvation. As no other genus of the Fagaceae has fruits with this combination of characters, a new genus is established and is referred to the subfamily Fagoideae. The Miocene genus seems most closely related to the extant genus Fagus.     

A new species of Williamsonia from the Upper Triassic Chinle Formation of New Mexico

Williamsonia nizhonia sp. nov., the first undoubted bennettitalean flower known from the Chinle Formation of Upper Triassic age in the south - western United States, is described in detail. The species is based on a single vertically compressed specimen collected from the Lower Red Member of the Chinle Formation near Fort Wingate in west-central New Mexico. It is rather small, the gynoecium is about 5 mm in diameter and is surrounded by a whorl often persistent sterile bracts about 1–5 cm long. The cuticles of the bracts and interseminal scales are 1 to 2 u thick. Stomata are only slightly sunken on the cuticles of the bracts and interseminal scales. Only a few hairs occur on the bracts. Williamsonia nizhonia cannot be attributed with any degree of confidence to either of the two bennettitalean leaves presently known in the Chinle flora.     

A Revaluation of the Systematic Positions of the Cercidiphyllaceae and Daphniphyllaceae Based on rbcL Gene Sequence Analysis,with Reference to the Relationship in the “Lower” Hamamelidae

The rbcL gene sequences of six species representing five subfamilies of the Hamamelidaceae and the Platanaceae were determined and used in the phylogenetic analysis on the “lower” Hamamelidae sensu Endress (1989) and its allies newly suggested. Four most parsimonious trees were obtained, all having 893 steps with CI = 0.558 and RI = 0.591. The families Cercidiphyllaceae, Daphniphyllaceae, Hamamelidaceae and Saxifragaceae are closely located, while the relationships among them remain unsolved even if more representatives of the Hamamelidaceae were further added in this parsimony analysis. Our results confirm the phylogenetic trees revealed by Chase et al. (1993) and Soltis et al. (1997), instead of those of Hoot and Crane (1996). Considering the morphological features they share, it is suggested that the Cercidiphyllaceae and Daphniphyllaceae be placed into the Hamamelidales. The relationship between the Platanaceae and the Hamamelidaceae shown in our analysis is not so closed as suggested by the cladistic analyses by using morphological characters only(e.g. Lu et al., 1991), while those among the Platanaceae, Trochodendraceae and Tetracentraceae are close as indicated by this study. The Eupteleaceae falls into the Ranunculales. The Eucommiaceae seems to show closer relationship with the Hamamelidaceae, the “core” family of the “lower” Hamamelidae, than with the other members except the Cercidiphyllaceae. The rbcL gene trees imply that the “lower” Hamamelidae is a heterogeneous group,composed of isolated ancient families.     

Frenelopsis alata and its microsporangiate and ovuliferous reproductive structures from the Cenomanian of Bohemia (Czech Republic, Central Europe)

The conifer, Frenelopsis alata (K. Feistmantel) E. Knobloch (Cheirolepidiaceae), occurring mostly in the Cenomanian of Europe, is revised on the basis of the type material. Its comparison with relevant species of Frenelopsis is discussed.The ovuliferous cone associated with the genus Frenelopsis is recorded for the first time. For the associated ovuliferous cones of Frenelopsis, a new genus, Alvinia, is introduced in a new combination for the type: Alvinia bohemica (Velenovsky) comb. n. Its association with Frenelopsis alata is based on the presence of Classopollis pollen adhering to ovuliferous cone scales, and the same type of pollen found in the microsporangiate cone of F. alata, the same cuticle pattern present on ovuliferous cones, sterile twigs and microsporangiate cones of F. alata, and also the co-occurrence of ovuliferous cones or their scales and sterile twigs of F. alata.Large ovuliferous cones of Alvinia bohemica are formed by helically arranged ovuliferous scales subtended by bracts. Each ovuliferous cone scale displays one or two seeds covered by a covering flap, and three appendages, which form distally a funnel-like structure lined in its inner part by long trichomes. Numerous pollen grains of Classopollis adhere to the trichomes, and the structure is considered to function as a protostigmatic area.The ovuliferous cones of Alvinia differ from similar cones of the Cheirolepidiaceae, Hirmeriella and Tomaxellia, mainly in a high state of unification of the ovuliferous cone scale, reduction of appendages and in a presence of the protostigmatic funnel-like structure.The ovuliferous cones, Alvinia bohemica, rarely occur intact, so it is assumed that they disintegrate when mature. It seems likely that they were not woody. This assumption is supported by the flattened appearance of cones and their cone scales in the sediment, their flexibility and the absence of massive coaly matter known from cones of the Taxodiaceae and Cupressaceae. It is proposed that this type of ovuliferous cone scale indicates a specialized type of pollination. In addition, it is suggested that cone scales enclosing seeds play an important role in propagation.     

Ultrastructure and development of oil cells in Laurus nobilis L. leaves

The oil cell development in Laurus nobilis leaves has been studied. At the early developmental stage, when the cell wall consists of the outer cellulose wall only, the oil cells differ from the neighbouring mesophyll cells in their larger size, lower starch content and in their plastid organization. After the deposition of the lamellated suberin layer and the inner cellulose layer, a wall protuberance (cupule) is formed on the periclinal wall facing the epidermis. From its reaction with periodic acid-hexamine-silver nitrate, it is suggested that the cupule is cellulosic. The portion of the inner cellulose wall layer bearing the cupule seems to contain patches of suberin. Plasmodesmata occur in special wall protuberances and appear to become occluded with age. The oil produced inside the protoplast is secreted to the outside of the plasmalemma, and accumulates as a drop at the place predetermined by the cupule. Except at the cupule, the oil drop is surrounded by the plasmalemma.     

Photosynthesis of bract and its contribution to seed maturity inCarpinus laxiflora

Light saturated net photosynthesis was measured in bracts and leaves ofCarpinus laxiflora, the major species in secondary forests in cool and intermediate temperate zones in Japan. The maximum net photosynthesis of leaves and bracts was essentially constant from May to early August and decreased gradually thereafter. For bracts, it was 3.2 μmol m⁻²s⁻¹, approximately half that for the leaves. The photosynthesis of bracts would thus appear to contribute significantly to seed maturity. The estimated production of bract based on the photosynthesis would make seeds (3 mg dry weight) mature for 37 days, assuming all photosynthate of the bracts to have been distributed in the seeds only. This was quite consistent with the growth curve for the seeds. A mast year phenomenon is discussed in relation to bract photosynthesis and leaf number.     

Morphological and ploidy level variation ofCentaurea phrygia agg. (Asteraceae) in the Czech Republic, Slovakia and Ukraine

Centaurea phrygia agg. was studied in part of Central Europe (Czech Republic, Slovakia and Ukraine) to evaluate its karyological and morphological variation. Three ploidy levels were found: diploid (C. pseudophrygia, C. stenolepis and several populations ofC. phrygia s.str.), tetraploid (C. oxylepis and several populations ofC. phrygia s.str.), and triploid (very rare, only single individuals). Only one taxon,C. phrygia s.str., comprises populations of two ploidy levels, but they seem to be geographically separated. Multivariate morphometric analysis confirmed the separation of the four taxa; the length and the width of appendages of middle involucral bracts, visibility of appendages of inner involucral bracts, the length and the width of an involucre, and the length/width ratio of middle cauline leaves are the most important discriminant characters. Several populations intermediate between two species (eitherC. pseudophrygia andC. stenolepis orC. oxylepis andC. phrygia s.str.) were found. Their possible origin from introgressive hybridization is discussed considering their morphology (intermediate between putative parental species), chromosome numbers (always the same as in putative parents), and distribution (both spatially and ecologically more or less intermediate between distribution ranges of putative parents). A determination key for the four studied species, including intermediates, is also presented.     

Structural analysis of the dissected ensiform leaves and shoot morphology of Marathrum foeniculaceum (Podostemaceae)

Foliage leaves of Marathrum foeniculaceum Humb. & Bonpl. (Podostemaceae–Podostemoideae) resemble pinnate compound leaves at first sight. But the similarity is deceptive, since studies of the leaf structure reveal the ensiform (sword-like) shape of the blade. The ribbon-shaped central rachis-like portion represents the parallel-veined ensiform blade that extends in the median plane direction. Pinnae, typically developing from the leaf margin of the blade in transverse position relative to the mother shoot axis, do not occur here, but instead, bi-pinnate-like appendages arise alternately at the adaxial and abaxial edge of the ensiform blade. The pinnate-like structures are accessory structures. These project only from one side (“front side”) of the ensiform blade. The appendages produce repeatedly forked threads that end in pubescent filaments. The trichomes are of the Zeylanidium olivaceum type. The occurrence of similar structures in species of Marathrum and the related genera Apinagia and Mourera are discussed.     

Optical and anatomical characteristics of bracts from the Chinese "glasshouse" plant,Rheum alexandrae Batalin (Polygonaceae), in Yunnan,China

Bracts that lacked chlorophyll were compared with rosette leaves on the Chinese glasshouse plant Rheum alexandrae Batalin. The structures were analyzed anatomically and with photospectrometry. Histological features were significantly different between the bracts and the rosette leaves. Epidermal pavement cells and palisade cells were larger in the bracts than in the rosette leaves, but the ratio of the intercellular spaces to the cells in the palisade layer was the same in the two structures. Absorption spectrum analyses of the half-translucent bracts showed that, despite their thinner structure, they absorbed ultraviolet (UV) radiation more efficiently than did the green rosette leaves. The characteristics of the R. alexandrae bracts were different from those of the Himalayan glasshouse plant Rheum nobile. These results suggest that R. alexandrae evolved bracts as an adaptive strategy to protect the inflorescence from UV radiation.     

越南壳斗科植物新记录种(英文)

记载了采自越南奠边省的越南新记录种Castanopsis gamblei Hickel et A.Camus。该种与C.jucunda Hance相似,但区别在于中脉在叶上面凸起,侧脉8~12对,壳斗外壁的刺长为1~1.5 cm,壳斗具短柄和坚果被伏毛等,并根据采自越南的标本,提供了C.gamblei的形态特征描述和绘图。     

Lithocarpus glaucus, a new species of Fagaceae from China

Lithocarpus glaucus (Fagaceae) is described and illustrated. L. glaucus resembles L. hancei , but can easily be distinguished by its bigger leaves, glabrous inflorescence rachis and the cupule only covering the base of the nut.     

论山毛榉科植物的系统发育

本文运用分支分类学方法,对山毛榉科植物进行了系统发育的分析。山毛榉科作为单元发生群包括柯属、锥属、粟属、三棱栎属、水青冈属和栎属。桦木科和南山毛榉属被选择作为外类群。对大量的性状进行评估之后,选择了25对性状作为建立数据矩阵的基本资料。性状极化以外类群比较为主,同时也采用了化石证据和通行的形态演化的基本原则。数据矩阵由7个分类群、2个外类群和25个性状组成。采用最大同步法、演化极端结合法和综合分析法对该数据矩阵进行了分析。在得到的3个树状分支图中按照最简约的原则,选出演化长度最短的谱系分支图作为本文讨论山毛榉科属间的系统演化关系的基础。关于山毛榉科植物的系统发育,作者的观点如下：(A)现存的山毛榉科的6个属形成了4条平行进化的分支路线,它们分别被处理作4个亚科,即：栗亚科,三棱栎亚科,水青冈亚科和栎亚科;(B)平行进化是山毛榉科植物系统发育过程中的主要形式。生殖过程中的一些特征,如：果实第二年成熟,胚珠通常败育等,是影响山毛榉科植物属间基因交流的主要原因。在现存的山毛榉科植物中,柯属是最原始的类群。三棱栎属和锥属的起源也较早,而栗属、水青冈属和栎属是特化的类群。     

壳斗科原始植物轮叶三棱栎在云南西双版纳的发现及其生物地理意义

于云南西双版纳发现了壳斗科植物的原始类群——轮叶三棱栎（Trigonobalanus verticillata Forman）。轮叶三棱栎被认为是栎属（Quercus L.）和水青冈属（Fagus L.）植物的祖先之一,原纪录分布于印度尼西亚和马来西亚,后来在我国海南岛被发现,其分布格局的形成一直未能合理解释。本次在云南新发现轮叶三棱栎,不仅可以解释它在海南岛的分布,也为海南岛历史上可能曾经连接着越南北部和广西西南部的假设提供了科学支持,具有重要的科研价值和生物地理学意义。