THE PHYLOGENETIC POSITION OF ANEMIA COLIMENSIS

The unique leaf structure of the genus Anemia with its upright fertile basal pinnae has been interpreted as derived from the typical fern leaf with unmodified basal pinnae. Reported herein for the first time is the leaf morphology of a species, Anemia colimensis Mickel, which shows the most primitive condition known in the genus and clearly confirms the course of evolution. The fertile pinnae are but little modified in size, lamination, and posture. Although A. colimensis has characters of two subgenera, it is shown to be a primitive element in subgen. Anemiorrhiza and not a member of subgen. Coptophyllum as previously reported.     

SPORE MORPHOLOGY IN THE DICKSONIACEAE. I. THE GENERA CYSTODIUM,THYRSOPTERIS, AND CULCITA

The most mature spores available in herbarium specimens of the dicksoniaceous genera Cystodium, Thyrsopteris, and Culcita were studied by scanning electron microscopy and light microscopy, and representative specimens were analyzed to determine the number of spores produced per sporangium. Thyrsopteris and Culcita feature 64-spored sporangia, but Cystodium is consistently 32-spored. Spores were analyzed both in their native state as found on the specimens and in a perine-free state achieved by treatment with sodium hydroxide or acetolysis mixture. The sodium hydroxide assay demonstrated the presence of a perine in Cystodium, Thyrsopteris, and Culcita subgenus Culcita, but no evidence of a perine so defined was found in Culcita subgenus Calochlaena. Spores of Cystodium feature a nearly psilate exine overlain by a striate inner perine and a granular outer perine and are in several respects similar to those of Metaxya in the cyatheoid-dicksonioid complex and to those of Saccoloma in the dennstaedtioids. The most mature Thyrsopteris spores available may not have been fully mature. They feature a sparsely distributed, granular perinous layer over a microverrucate sculptine. The latter topography is taken as largely perinous since treatment with sodium hydroxide left a nearly psilate exine. The spore morphologies of Cystodium and Thyrsopteris reinforce the taxonomic distinctness of these monotypic genera indicated by their other characters. The two subgenera of Culcita are very dissimilar in their spore morphologies. The exine in subgenus Culcita ranges from psilate to slightly microverrucate proximally and distally, with varying margo development. Spores of subgenus Calochlaena are strongly differentiated from those of subgenus Culcita by their exine of broad spinules which vary in their degree of lateral fusion to each other and in the granular appearance of their distal surfaces. Spore morphology in Culcita strongly supports the argument of those who would raise its subgenera to generic rank.     

SPORE MORPHOLOGY IN THE CYATHEACEAE. III. THE GENUS TRICHIPTERIS

Scanning electron microscopy supported by light microscopic L-O analysis is used in a palynological study of the genus Trichipteris of the tree fern family Cyatheaceae. The spores of all but two of the 55 species are investigated and the results are related to previous findings for Trichipteris species in the literature. A perine layer consisting of a network of slender, smooth- or rough-textured interlocking strands with free ends uniformly characterizes the genus and is the same as the perine type previously reported in neotropical species of Sphaeropteris excluding the S. horrida group. The exine is analyzed both in spores which have not yet developed the perine layer and in spores whose perine has been removed by chemical treatment. Exine sculpturing shows great variation in the genus, ranging from essentially psilate to variously pitted (foveolate, foraminate), with topography ranging from plane to verrucate-tuberculate, and with the verrucae-tubercles themselves often variously pitted. In many instances, exine sculpturing types correlate with the infrageneric species groupings or affinities hypothesized by the recent monographers. In other cases, palynological characters offer new insight into species relationships that were previously unclear to monographers or that were interpreted differently on the basis of other characters. The exine sculpturing types reinforce the relationship evident between Trichipteris and neotropical Sphaeropteris on the basis of perine morphology.     

POLLEN MORPHOLOGY IN THE GENUS ERYTHRONIUM (LILIACEAE) AND ITS SYSTEMATIC IMPLICATIONS

Pollen morphology was examined in 40 samples from 19 species in the genus Erythronium (Liliaceae) using scanning (SEM) and transmission electron microscopy (TEM). Pollen grains are monosulcate monads, except for a plant of E. oregonum which has dyad grains. North American and European species are characterized by reticulate exine sculpture composed of various degrees of wavy muri and variably-sized lumina. The most distinctive feature of exine sculpture in the genus is exhibited by the Asian species E. japonicum, which has a unique reticulate pattern composed of striate muri and a distinctive exine structure without columellae. The distinctness of E. japonicum pollen suggests that it has specialized in isolation from species in North America and Europe.     

SPORE MORPHOLOGY IN THE CYATHEACEAE. II. THE GENERA LOPHOSORIA,METAXYA, SPHAEROPTERIS,ALSOPHILA, AND NEPHELEA

Scanning electron microscopy and transmitted light microscopy are used in a palynological study of Lophosoria, Metaxya, Sphaeropteris, Alsophila, and Nephelea of the tree fern family Cyatheaceae. The monotypic American genera Lophosoria and Metaxya each have a unique spore morphology which reinforces the taxonomic distinctness of these genera as indicated by their other characters. All investigated paleotropical species of Sphaeropteris develop a single type of perine characterized by coarse, pointed projections. In the neotropics, the Sphaeropteris horrida group shares this perine type, whereas all other neotropical Sphaeropteris species appear to have a different kind of perine with fine hair-like processes. The exine in paleotropical Sphaeropteris appears uniformly unsculptured, whereas in the neotropics several exine morphologies are found. In Alsophila all investigated neotropical species and the vast majority of the paleotropical species are characterized by a basically ridged perine morphology and an unsculptured exine. In several paleotropical Alsophila species, however, a perine with hair-like processes similar to those in neotropical Sphaeropteris is found, and the exine in several species is variously pitted. In at least one paleotropical Alsophila species, the porate exine morphology is indistinguishable from that in the neotropical genus Cnemidaria. The spores of the American genus Nephelea are similar to those of the majority of Alsophila species in ridged perine morphology and unsculptured exine. Several new instances of atypical spore numbers per sporangium are reported in Sphaeropteris and Alsophila. These and the palynological data are discussed in a taxonomic framework. The spore morphology in these genera is consistent with Tryon's recent generic revision of the family.     

Taxonomic implications of pollen exine morphology in infrageneric classification of Scutellaria (Lamiaceae)

Scutellaria L. in Lamiaceae subfamily Scutellarioideae is a subcosmopolitan genus with about 360 species. According to the latest subgeneric classification, two subgenera are recognized: S. subgen. Scutellaria and S. subgen. Apeltanthus. We studied pollen grains from 29 species of Scutellaria belonging to both subgenera and from both the Old and the New World to evaluate their taxonomic importance for the infrageneric classification of the genus. Pollen grains were acetolysed and studied by scanning electron microscope (SEM) and light microscope (LM). All examined pollen grains are isopolar, tricolpate, suboblate, oblate spheroidal, prolate spheroidal to subprolate. The exine is mainly bireticulate perforate, but with variations in lumina shape and size as well as perforation size and uniformity. Based on the exine sculpturing, two subtypes are recognized within the bireticulate pollen type. In subtype I the primary reticulum of the exine consists of angular muri; the lumen has an irregular polygonal shape and the perforations of the secondary reticulum are more or less uniform and of the same size. This pollen subtype was observed in species of subgenus Scutellaria, sectt. Scutellaria p.p., Anaspis, Perilomia and Salazaria. In subtype II the primary reticulum of the exine consists of a more or less curved murus; the lumen is rounded or obtusely angular and the secondary reticulum consists of one or more large central perforations surrounded by some smaller ones. This pollen subtype was observed in species of subgenus Scutellaria sectt. Scutellaria p.p., Salviifoliae and in all members of subgenus Apeltanthus. The results of this study reveal that the exine ornamentation is a diagnostic character useful for the infrageneric classification of Scutellaria.     

SPORE WALL FORMATION AND CHLOROPLAST DEVELOPMENT DURING SPOROGENESIS IN THE MOSS FISSIDENS LIMBATUS

The sequence of wall formation in spores of Fissidens limbatus Sullivant is as follows: The exine is formed around the protoplasts after the sporocyte has undergone meiosis. The fully enlarged spores then become coated by the perine; this is followed by intine formation. The source of the intine and exine appears to be from within the spore, but the perine is of an apparent exogenous origin. Ornamentation of the spore is due solely to deposition of the perine. Each spore originally has a single plastid. Plastids increase in number by fission, resulting in mature spores with numerous plastids with well differentiated lamellae.     

山茶属的花粉形态及其分类学意义

本文对山茶属(Camellia L.)18个组27个代表种的花粉进行了光学显微镜、扫描电镜和大部分进行了透射电镜的观察,并对花粉大小、形状、外壁纹饰和超微结构等作了综合的比较。结果表明,其形状和大小差异不很明显。花粉壁的层次、厚度和不同层次的比例,如复盖层与柱状层以及外壁外层与外壁内层的比例等也没有显著的差异。但花粉壁的纹饰特征在扫描电镜下显示出较大的差异,具有较重要的分类学价值。根据其纹饰特征,可以把山茶属花粉大致区分为六个类型:皱疣状纹饰;粗瘤状纹饰;颗粒状至皱-颗粒状纹饰;穴-网状纹饰;皱沟状纹饰及皱波-念珠状纹饰。孢粉学上区分的类型不完全与各个学者从植物形态上划分的组相一致。其中管蕊茶 Camellia lanceolata的纹饰非常特殊(粗瘤状),其外壁表面很象牛心果(Annona reticulata)的外形特征,为其重新分类提供孢粉学依据。     

Phylogeny and classification of the Xeromelissinae (Hymenoptera: Apoidea, Colletidae) with special emphasis on the genus Chilicola

Abstract A phylogenetic analysis and classification are provided for the bee subfamily Xeromelissinae based on 248 morphological characters, many of which are novel and illustrated. A total of 47 ingroup species was included in the analysis, representing at least two divergent members from each described genus or subgenus and seven taxa which did not readily fall within previously described subgenera. Three most parsimonious trees were found (length, 1508; consistency index, 40; retention index, 70). The result shows that Xeromelissa renders Chilimelissa paraphyletic, and the 20 known Chilimelissa species are reassigned to Xeromelissa, giving the following new combinations: X. luisa (Toro & Moldenke) (this is the type species of Chilimelissa), X. mucar (Toro & Moldenke), X. xanthorhina (Toro), X. brevimalaris (Toro), X. rosie (Toro and Packer), X. laureli (Toro and Packer), X. chusmiza (Toro), X. longipalpa (Toro), X. pedroi (Toro & Moldenke), X. australis (Toro & Moldenke), X. chillan (Toro & Moldenke), X. farellones (Toro & Moldenke), X. machi (Toro), X. minuta (Toro & Moldenke), X. nortina (Toro & Moldenke), X. sielfeldi (Toro & Moldenke), X. obscura (Toro & Moldenke), X. irwini (Toro & Moldenke), X. nolanai (Toro & Moldenke) and X. rozeni (Toro & Moldenke). Group support was estimated using symmetric resampling and group supported/contradicted (GC) ratios, which compare the frequency of each most parsimoniously resolved clade with the alternative arrangement that was most commonly found in resampling. Relationships among subgenera for Chilicola are weakly supported. By contrast, when three previously synonymized subgenera (Stenoediscelis, Heteroediscelis and Oediscelisca) are resurrected, there is good support for all subgenera (GC ≥ 99), except two: a paraphyletic Oediscelis and a polyphyletic Anoediscelis. Both of these subgenera became monophyletic following successive approximations character weighting. Four distinctive new subgenera are described: Unicarinicola Packer subgen.n. , Obesicola Packer subgen.n. , Capitatiscopa Packer subgen.n. and Toroediscelis Packer subgen.n. , and a revised key to the subgenera of Chilicola is provided.     

Studies on Timmiella barbuloides (Brid.) Moenk., IV. SEM and TEM characterization of spore wall and first germination stages

Abstract

The spore wall morphology of Timmiella barbuloides (Pottiales, Musci) is described. The spores are catalept, with an ornamentation pattern consisting of unevenly spaced, shortly pedunculated pilum-and gemma-like processes. The spore coat consists of three, unevenly thick layers: intine, exine, and perine. The exine is not involved in wall ornamentation, the processes consisting of perine only. The leptoma, a spore coat area involved in germination, consists of an intine markedly thickening in an area of thinning exine and, outside, with a spore coat area where perinous processes become sparse. On the basis of observations and of the data reported in recent literature the classical definition of the leptoma is modified. It is considered to be a structurally specialized, but not necessarily thin, area.     

The palynology of the genus Rondeletia L. (Rubiaceae-Cinchonoideae-Rondeletieae)

Pollen of 20 species of Rondeletia, covering three subgenera and seven sections or “species groups” of the genus, was studied using light and scanning microscopy. Rondeletia, characterized by binucleate mature pollen grains like numerous other Rubiaceae, was found to be eurypalynous. The pollen is isopolar and small-sized (average equatorial diameters 11.4–22.8 μm) and 3-colporate (rarely 4-colporate). In equatorial view, the pollen grains are mostly ± spheroidal (rarely suboblate); in polar view (ambitus), they are mainly circular or semiangular (intersemiangular in one species only). Three different exine types are distinguishable: exine with 1) tectum minutely perforate, perforations usually isodiametric, 2) tectum with comparatively large, not isodiametric perforations or 3) coarsely reticulate; supratectal sculpturing elements are lacking; the width of the perforations and lumina is either equal or different at the apo- and mesocolpia; in a few species rod-like luminal processes are present. Palynological features of most of the investigated taxa tend to overlap so that palynology is not very helpful in supporting the subgeneric division of Rondeletia. It was, however, noted that pollen morphology, to some extent, supports the sections of subgen. Arachnothrix. Palynologically, the subgen. Rogiera was found to be heterogeneous in that each of the three investigated species is characterized by a different exine type; one of these, R. strigosa, differs from all other Rondeletia species investigated in having a coarsely reticulate exine. R. odorata (subgen. Rondeletia) differs from all other investigated species in its intersemiangular pollen shape.     

Spore morphology of some Bruchiaceae species (Bryophyta) from Brazil

The spores of Bruchia uleana, B. uruguensis, Eobruchia bruchioides, Trematodon ambiguus, T. aureus, T. brevifolius, T. longlcollis, T. reflexus and T. vaginatus were studied by light and scanning electron microscopy. The spore wall of the family Bruchiaceae includes sclerine (the distinction between exine and perine may be difficult to define) and intine. The aperture may be surrounded or not by one or more rings of ornamentation elements. Two basic types of spore were recognized: one characterized by a gemmoid surface and the other with elongated processes and two types of ornamentation in the apertural region. The spores of the taxa studied support the separation of the Bruchiaceae from the Dicranaceae.     

PpASCL,the Physcomitrella patens Anther-Specific Chalcone Synthase-Like Enzyme Implicated in Sporopollenin Biosynthesis,Is Needed for Integrity of the Moss Spore Wall and Spore Viability

Sporopollenin is the main constituent of the exine layer of spore and pollen walls. The anther-specific chalcone synthase-like (ASCL) enzyme of Physcomitrella patens, PpASCL, has previously been implicated in the biosynthesis of sporopollenin, the main constituent of exine and perine, the two outermost layers of the moss spore cell wall. We made targeted knockouts of the corresponding gene, PpASCL, and phenotypically characterized ascl sporophytes and spores at different developmental stages. Ascl plants developed normally until late in sporophytic development, when the spores produced were structurally aberrant and inviable. The development of the ascl spore cell wall appeared to be arrested early in microspore development, resulting in small, collapsed spores with altered surface morphology. The typical stratification of the spore cell wall was absent with only an abnormal perine recognisable above an amorphous layer possibly representing remnants of compromised intine and/or exine. Equivalent resistance of the spore walls of ascl mutants and the control strain to acetolysis suggests the presence of chemically inert, defective sporopollenin in the mutants. Anatomical abnormalities of late-stage ascl sporophytes include a persistent large columella and an air space incompletely filled with spores. Our results indicate that the evolutionarily conserved PpASCL gene is needed for proper construction of the spore wall and for normal maturation and viability of moss spores.     

A COMPARATIVE STUDY OF CELL DIVISION PATTERNS DURING GERMINATION OF SPORES OF ANEMIA,LYGODIUM AND MOHRIA (SCHIZAEACEAE)

Cell division patterns during germination of spores of Anemia (A. hirsuta, A. munchii, A. phyllitidis), Lygodium (L. circinatum, L. flexuosum, L. japonicum, L. salicifolium) and Mohria caffrorum have been examined by light microscopy of glycol methacrylate embedded materials. Spores of all species in a genus exhibited a constant pattern of division under different conditions of germination. In spores of species of Anemia, following an asymmetrical division, the proximal cell differentiated into the protonemal cell while the distal cell divided to produce the rhizoid. A similar division sequence was found in spores of Mohria caffrorum, but the fate of cells formed was reversed. In Lygodium spores, a proximal cell formed by an initial division of the spore cut off a protonemal cell, a rhizoid and a wedge-shaped cell by walls parallel to the polar axis. Our results contradict earlier observations on cell division sequence during germination of spores of these genera based on whole mount preparations.     

Ultrastructure of the spore in four Japanese species of Ptychomitrium Fürnr. (Musci)

The ultrastructure of the mature spore in four Japanese species of the acrocarpous moss genus Ptychomitrium is presented. In all species the spores have a similar pattern: there is no recognisable aperture nor sporoderm polarity, exine and perine are poorly developed, cytoplasm only occasionally shows polarity, and plastids have a well developed inner membrane system. The presence of frequent intine protrusions is a remarkable feature of this genus. A multilaminar structure of the exine, already observed in Grimmia, occurs also in these species although here it is less pronounced. The significance of these features is discussed within these species, as well as in comparison to other taxa, especially the genus Grimmia.     

THE SPORE PATTERN IN SOME SPECIES OF CHEILANTHES

Of the 32 taxa examined, 13 contained 32 spores in each sporangium and are considered apo-gamous, 14 were sexual species with 64 spores per sporangium, and 5 had 32 spores in some sporangia and 64 in others. When considered as a whole, the spores ranged in size from 29.9 to 74.88μ. Most species had oval or globose spores but several had tetrahedral spores. The spores of all were radially symmetrical. Almost all of the species possessed a crassimarginate type of laesura and all except C. cooperae and C. viscida had a perispore. The ornamentation of the perispore showed the following patterns: napate, granulate, psilate, lobate, foveate, and echinate. The exine pattern was predominantly psilate but foveate, rugulate, napate, and granulate conditions were observed. Seventeen taxa were found to have some degree of spore abortion.     

SPORE WALL DEVELOPMENT IN ANDREAEA (MUSCI: ANDREAEOPSIDA)

The spore wall of Andreaea rothii (Andreaeopsida) is unique among mosses studied by transmission electron microscopy. The exine of other mosses is typically initiated on trilaminar structures of near unit membrane dimensions just outside the plasma membrane. The exine of Andreaea is initiated in the absence of such structures as discrete globules within the coarsely fibrillar network of the sporocyte wall. The sequence of wall layer development, nevertheless, is essentially like that of other mosses. The intine is deposited within the exine and the perine accumulates on the surface of the exine during the latter stages of spore maturation. The mature spore is weakly trilete and inaperturate. The wall consists of three layers, the inner intine, the spongy exine consisting of loosely compacted irregular globules of sporopollenin, and an outer layer of perine. The perine differs ultrastructurally from the exine only in its greater degree of electron opacity. This ultrastructural evidence of departure from the fundamental pattern of exine development in mosses supports the taxonomic isolation of Andreaea from mosses of the Sphagnopsida and Bryopsida.     

Pollen morphology of selected Central European species from subgenera Vignea and Carex (Carex,Cyperaceae) and its relation to taxonomy

This study analysed the taxonomic utility of selected features of pollen grains of 45 Central European species of subgenera Vignea and Carex of the genus Carex. Seven quantitative features were analysed: [length of polar axis (P), length of equatorial axis (E), exine thickness on the pole (Exp), exine thickness on the equator plane (Exe), P/E ratio and the relative thickness of exine (Exp/P and Exe/E ratio)] and outline, shape and exine sculpture. Among the biometrical features, the most important for Carex taxonomy (particularly at the level of subgenus) is the thickness of exine (Exp). Marked differences in the morphological structure of inflorescences at the subgenus level are reflected in the differences of pollen features. Results of our studies clearly show an explicit (and not previously described in the palynological literature) taxonomic division of the genus Carex on the basis of pollen biometrical features into two units corresponding exactly to the subgenera (Vignea and Carex). However, the features of pollen grains analysed did not contribute any essential taxonomic criteria at levels lower than subgenus (e.g. sections). An exception was for C. disticha, where it was observed that the poroid areas occurred in pairs, a new feature for sedges. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 422–439.     

Pollen morphology in Psychotria (Rubiaceae, Rubioideae, Psychotrieae) and its taxonomic significance. A preliminary survey

The pollen morphology in 168 species of Psychotria (Rubiaceae, Rubiodeae, Psychotrieae) has been investigated using light microscopy and, for 61 of the speices, scanning electron microscopy. Transmission electron microscopical studies have been carried out for seven of the species. Psychorria is very heterogeneoous pollen morphologically and pollen grain characteristics cannot be used for the delimination of the basis of aperture morphology, thickness of exine, size of lumina, muri, columellae and bacula, and sculpture. A key to the identificantion of the pollen types is presented and all types are issstrated. The pollen grains in Psychotria are usually 3–to 5colporte, 3-to 5-colpate or inapertuarate, rarely 2–4-or 5-porate, and have an exine that vanes widely in thickness. The sexine is reticulate, microreticulate, tectate-perforate, rugulate or intectate, and smooth or sculptured. Exine morphology presents important characters for the taxonomic subdivision of Psychotria . Previous intrageneric classifications are in part supported by pollen morphology, but contradictions between this and other sets of charactes, such as inflorescence features. are common.     

杜鹃花属植物花粉形态及其分类学意义

利用扫描电子显微镜对5个亚属20种杜鹃花属植物的花粉形态进行了观察和比较研究,其中大部分(16种)为首次报道。杜鹃花属花粉均为四合花粉,呈正四面体排列。四合体为圆角三角形,连接紧密。单粒花粉为球形或近球形,具三沟孔。在扫描电镜下,除了杜鹃亚属的百合杜鹃、羊踯躅亚属的羊踯躅以及马银花亚属的马银花组具有明显的纹饰特征之外,其它类群的形态特征相互重叠,不足以作为现有亚属的分类依据。花粉粒具不同的外壁纹饰,可为分类研究提供孢粉学方面的证据,但应慎重应用花粉形态对杜鹃花属植物特定种进行分类鉴定。