Ovules and seeds in Acalyphoideae (Euphorbiaceae): structure and systematic implications

Acalyphoideae, the largest subfamily of Euphorbiaceae, are investigated with respect to ovule and seed structure on the basis of 172 species of 80 genera in all 20 tribes of Acalyphoideae sensu Webster. All species of Acalyphoideae examined have bitegmic ovules with a non-vascularized inner integument. However, noticeable differences exist among and sometimes within the genera in the thickness of the inner and outer integument, the presence or absence of vascular bundles in the outer integument, whether ovules are pachychalazal or not, the presence or absence of an aril, seed coat structure (in terms of the best-developed mechanical cell-layer), and the shape of cells constituting the exotegmen. For the latter two characters, two different types of seed coat (i.e., "exotegmic" and "exotestal") and three different types of exotegmic cell (i.e., palisadal, tracheoidal and ribbon-like) were distinguished. Comparisons showed that three tribes Clutieae, Chaetocarpeae and Pereae are distinct from the other Acalyphoideae as well as from the other Euphorbiaceae in having an exotestal seed coat with a tracheoidal exotegmen. The tribe Dicoelieae is also distinct from the other Acalyphoideae in having an exotegmic seed that is composed of ribbon-like cells of exotegmen (i.e., cells both longitudinally and radially elongated, sclerotic and pitted). The tribe Galearieae, which should be treated as a distinct family Pandaceae, is also distinct from the other Acalyphoideae in having an exotegmic seed with a tracheoidal exotegmen (i.e., cells longitudinally elongated, sclerotic and pitted). The remaining genera of Acalyphoideae always have an exotegmic seed with a palisadal exotegmen (i.e., cells radially elongated, sclerotic and pitted). The shared palisadal exotegmen supports the close affinity of Acalyphoideae (excluding five tribes) with Crotonoideae and Euphorbioideae. Within the remaining genera of Acalyphoideae, a significant diversity is found in ovule and seed morphology with respect to the thickness of the inner and outer integument, the size of chalaza, vascularization of an outer integument and an aril.     

Morphology, anatomy and histochemistry of Salicornioideae (Chenopodiaceae) fruits and seeds

BACKGROUND AND AIMS: The subfamily Salicornioideae (Chenopodiaceae) are a taxonomically difficult group largely due to the lack of diagnostic characters available to delineate tribal- and generic-level boundaries; a consequence of their reduced floral and vegetative features. This study examined the variation in fruits and seeds across both tribes of the Salicornioideae to assess if characters support traditional taxonomic sections. METHODS: Light microscopy, environmental scanning electron microscopy and anatomical ultra-thin sectioning were employed to examine variation in fruits and seeds. Sixty-eight representatives across 14 of the 15 genera currently recognized within the tribes Halopeplideae and Salicornieae were examined to determine whether characters support current taxonomic groups. KEY RESULTS: Characters such as seed coat structure, embryo shape, seed orientation, the forms of seed storage proteins and carbohydrates show variation within the Salicornioideae and may be phylogenetically useful. The campylotropous ovule typical of the Chenopodiaceae generally results in a curved embryo; however, many Halosarcia and Sclerostegia species have straight embryos and in Salicornia and Sarcocornia the large peripheral embryo appears bent rather than curved. Seed coat ornamentation of Microcnemum and Arthrocnemum is distinct from other Salicornioideae as the elongated epidermal cells of the exotesta have convex walls. Histochemical stains of anatomical sections of cotyledon cells showed protein bodies were variable in shape, and starch grains were present in some species, namely Salicornia bigelovii, S. europaea and Allenrolfea occidentalis. CONCLUSIONS: While fruits and seeds were found to be variable within the subfamily, no synapomorphic characters support the tribe Halopeplideae as these genera have crustaceous seed coats, curved embryos and abundant perisperm; features characteristic of many of the tribe Salicornieae. The endemic Australian genera are closely related and few seed and fruit characters are diagnostic at the generic level. Nineteen characters identified as being potentially informative will be included in future phylogenetic analyses of the subfamily.     

C-Glycosylflavones and xanthones in leaves of Rigidella,sessilanthera and Fosteria

Four New World genera are included in the tribe tigrideae of the Iridaceae. These genera, which have been the subject of recent systematic treatments [1–4], share many characteristics; e.g. a haploid complement of two large and 12 small chromosomes and bisulcate pollen grains. However, the taxonomic and phyletic relationships within and between these genera have been based strictly on floral morphology and may simply reflect the primary pollinators of these genera [4,5].The flavonoid chemistry of eight species in three of the four genera, Rigidella, Sessilanthera and Fosteria, was investigated as part of a systematic study of Tigrideae. Our results are summarized in Table 1 nad Fig. 1. Although a recurrent pattern of $\text{C-}\text{glycosylflavones}$ and xanthones characterize the leaves of these taxa, each species exhibits a distinctive array of compounds. The same classes of compounds occur in other tribes of the Iridaceae: $\text{C-}\text{glycosylflavones}$ occur in the Irideae [6,7], Cipureae, and Mariceae and xanthones in Irideae [6] and Sisyrinchieae [6].     

Systematic and phylogenetic significance of the seed coat in the shrubby African Iridaceae, Nivenia, Klattia and Witsenia

MANNINGJ. C. & GOLDBLATT, P., 1991. Systematic and phylogenetic significance of the seed coat in the shrubby African Iridaceae, Nivenia, Klattia and Witsenia. The seeds of Nivenia, Klattia and Witsenia, a natural alliance within Nivenioideae, are among their most distinctive features, and seed number and shape constitute at least two synapomorphies for this monophyletic lineage. In this paper we survey the structure of the seed surface of five species of Nivenia and one each of Klattia and Witsenia by scanning electron microsopy (SEM), and study the development of the seed coat in a representative species of each of the three genera. Outgroups for comparison were selected from genera inside and outside the subfamily. The six genera of Nivenioideae are united in having a 3 (– 2) seriate outer integument but the shrubby genera are unique in the family in their tangentially flattened ovules which mature into depressed, flat, scutiform seeds. They display a range of variation in seed coat characters but are specialized in the subfamily and family in having a transparent outer integument. Other genera have pigmented deposits in the outer epidermis of the outer integument. Nivenia and Witsenia are further specialized in having a partially exfoliating outer integument. Klattia is unique among the shrubby genera in having deposits in the second layer of the tegmen, in retaining an intact outer epidermis of the tegmen, and in the fusiform shape of the epidermal cells and striate surface of the seed. Our results are incorporated in a cladogram that expresses our current understanding of the phylogenetic relationships of Nivenioideae.     

The Impact of Molecular Methods on the Systematics of Angiosperms

A comparison is made between the systematics of selected orders and families based on morphology and other “classical” characters on the one hand, and the results of molecular methods on the other hand. It can be shown that taxa defined by a broad array of characters from morphology, anatomy, embryology and phytochemistry usually are confirmed by molecular results. On the other hand a family like the Saxifragaceae s.l. delimited solely on the basis of floral morphology has been shown to be grossly polyphyletic. Some quite surprising results of the molecular analyses usually agree with some embryological or phytochemical characters, and sometimes even with characters of vegetative morphology and anatomy. As a special case “unequal ancient splits” are discussed, where one clade contains few genera and species usually retaining many primitive characters, and the other shows great diversity and contains the more advanced members.     

Floral Morphology and Relationships of Clusia gundlachii with a Discussion of Floral Organ Identity and Diversity in the Genus Clusia

The genus Clusia L. is highly variable in many floral features. Several Clusia species have floral organs of mixed or uncertain identity, such as organs that are transitional between bracteoles and sepals, petaloid sepals, and partly petaloid stamen rings. Unique in Clusia is the "corona" of Clusia gundlachii Stahl, a thick, urn-shaped structure that is initiated as a ring primordium. In male flowers it surrounds a synandrium, and in female flowers it surrounds the ovary and a row of staminodes. The corona combines features typical of both petals and stamens of other Clusia species. It is hypothesized that this corona may be the result of the altered expression patterns of the genes that determine floral organ identity. Clusia gundlachii has many floral features in common with two small genera that are sometimes included in Clusia: Havetiopsis and Oedematopus. These genera have four thick connivent petals. Their apparent close relationship makes it seem likely that the corona of C. gundlachii evolved via congenital fusion of such petals. The corona is also somewhat similar to the staminodial rings present in many Clusia species, but taxa in which such organs occur show little similarity to C. gundlachii in terms of other floral characters.     

Seed micro‐morphology and its systematic significance in Gypsophila (Caryophyllaceae) and allied genera

In order to examine the systematic application of seed‐coat micro‐morphology in Gypsophila and allied genera, seed surfaces of 30 species and two varieties representing four genera of tribe Caryophylleae were examined with scanning electron microscope. The seeds of examined species range between 0.5–2.1 mm in length and 0.3–2.4 mm in diameter. The exomorphology of the seed coat shows two distinctive cell patterns. The epidermis is constructed either of elongated polygonal or of broad polygonal cells. The elongated type is the most common among the studied species, but the variation in alignment of testa cells, their size and shape as well as the density of protuberances may provide further information and useful diagnostic characters at generic and specific rank. The testa cells in Gypsophila and Saponaria are shallowly undulate, deeply undulate, lobed and armed at anticlinal walls. Deeply undulate anticlinal walls were observed in both Gypsophila and Ankyropetalum and a few species of Saponaria. Non‐ or indistinctly grooved anticlinal walls is the more common type in Allochrusa. Seed‐coat characters support the separation of Gypsophila and Saponaria to some extent but disagree with recognition of Ankyropetalum as a genus separate from Gypsophila.     

Ultrastructure and diversity of recent and fossil zona-aperturate pollen grains

A survey of recent and fossil zona-aperturate pollen grains within the angiosperms was undertaken. Zona-aperturate pollen (with complete ring-like apertures) has been evolved independently in several genera of basal angiosperm families (Nymphaeaceae, Eupomatiaceae, Annonaceae, Monimiaceae, Atherospermataceae) and monocots (Araceae, Iridaceae, Laxmanniaceae, Arecaceae, and Rapateaceae). The special case of the eudicot Limnanthes (Limnanthaceae) is discussed. New examples of recent and fossil fully zonate pollen are presented; a noteworthy new example are Scrophulariaceae, with Pedicularis; our fossil examples show affinities either to Nymphaeaceae, or Araceae, or Iridaceae, or cannot be related to an extant taxon. The zona-aperturate pollen grains differ in ornamentation and stratification mostly in the respect of the aperture areas, but sometimes also outside the aperture. The question of polarity is settled only for some taxa because of the frequent lack of tetrad observations. A ring-like aperture may divide the pollen grains in symmetric halves, or if running asymmetrically, divides the pollen grain in two more or less unequal halves; the presence of clearly unequal halves gives a strong argument to assume an equatorial ring in such cases where tetrad configurations were not available. The zona-aperturate condition may be a functional benefit in wet environments: while in dry pollen the apertural ring is completely closed, in wet or very moist realm it expands greatly, and the pollen tube can be formed quickly and everywhere in this area.     

Relationship between subfamilies,tribes and genera in iridaceae inferred from chemical characters

Free amino acids and γ-glutamyl peptides have been examined in 22 species of Iridaceae. 3-(3′-Carboxyphenyl)alanine and 3′-carboxyphenylglycine, previously known from the tribes Irideae and Tigridideae in the subfamily Iridodeae have been identified also in the tribe Mariceae of Iridoideae and the genera Bobartia, Orthrosanthus and Libertia of the subfamily Sisyrinchioideae. γ-Glutamyl peptides, previously known from the tribe Irideae, have been found also in the tribe Mariceae, both tribes being from subfamily Iridoideae. γ-Glutamyl-S-methylcysteine, γ-glutamylmethionine and the corresponding sulphoxides are the dominating γ-glutamyl peptides in the genera Dietes, Gynandriris, Moraea (tribe Irideae), Neomarica and Trimezia (tribe Mariceae), whereas γ-glutamyl peptides with non-sulphur amino acids are predominant in genera Ferraria, Hermodactylus, Homeria, Iris, Iridodyctyum and Xiphium (tribe Irideae). Dietes robisoniana, endemic to Lord Howe Island, has the same technical characters as other Dietes species from Southern Africa. The results are discussed in relation to botanical classification of and within the subfamilies Iridoideae and Sisyrinchoideae.     

ENDOTHECIUM IN IRIDACEAE AND ITS SYSTEMATIC IMPLICATIONS

An examination of the endothecial thickenings in 44 species of Iridaceae, selected from the four subfamilies and all major tribes, provides useful information about generic and tribal relationships in the family. U-shaped thickenings occur in Nivenioideae and Iridoideae—Sisyrinchieae, the latter the least specialized tribe of its subfamily. The occurrence of helical thickenings in all members examined of Iridiodeae tribes Irideae, Mariceae, and Tigridieae (a putatively monophyletic group) and Ixioideae is consistent with the recognition of these two lines as distinct taxa based on anatomical, morphological, phytochemical, and in the case of Ixioideae, palynological criteria. Baseplate thickenings are restricted to Patersonia. However, the shrubby Cape genera—Nivenia, Klattia, and Witsenia—have U-shaped thickenings which show a tendency for the bars on the inner periclinal cell walls to anastomose, suggesting a trend towards the baseplate condition in Patersonia. This accords with a suggested relationship between these genera, based on anatomical and flavonoid similarities. The pattern of variation in endothecial thickenings in Iridaceae is consistent with the phylogeny proposed by Goldblatt (1990). The distribution of thickening types within the family does not make it possible to polarize this character, but the most parsimonious interpretation assumes that U-shapes are basic. However, in at least some other monocotyledonous families the pattern suggests that U-shaped thickenings are derived from helices.     

Microtubule-disrupting drugs increase the frequency of conversion of a rat mammary epithelial stem cell line to elongated, myoepithelial-like cells in culture

Rat mammary (Rama) 25 cuboidal epithelial stem cells convert at a low frequency to elongated, Thy-1-positive, myoepithelial-like cells in culture; one such cell line is termed Rama 29. Addition of increasing concentrations of the microtubule-disrupting drug colchicine to sparse cultures of Rama 25 dramatically increases the percentage of colonies containing elongated cells and the percentage of Thy-1-positive cells when the drug is removed. Similar results on the formation of elongated cell colonies are obtained with other microtubule disruptors, such as vinblastine, vincristine, demecolcine, and nocodazole. The inactive analogues of colchicine beta- and delta-lumicolchicine and the microfilamental-disruptors cytochalasin B and D are without effect on the formation of elongated cell colonies and Thy-1-positive cells. For a given concentration of colchicine the percentage of elongated cell colonies and Thy-1-positive cells increases the longer the cells are exposed to the drug (range 8-96 hr) and the longer the drug-treated cultures are subsequently grown in drug-free medium. Colchicine fails to display this morphological change on Rama 29 elongated cells and on Rama 600 epithelial cells from a rat mammary metastasizing tumor. Immunofluorescent localization of antisera to tubulin confirms that colchicine disrupts the microtubules in all three cell lines at similar concentrations (0.1 to 1 microM) to those required to increase the percentage of elongated cell colonies in Rama 25. The DNA synthesis inhibitor cytosine arabinoside fails to inhibit this conversion process, and time-lapse cinematographic studies confirm that the conversion of a cuboidal to an elongated cell can take place without cell division. However, cell division may sometimes be required for subsequent stabilization events. Treatment of Rama 25 cells with colchicine under the same conditions also increases the abundance of elongated cell (Rama 29)-associated polypeptides, and elongated cell clones isolated after such treatment show an overall pattern of protein synthesis very similar to that of Rama 29.     

THECATE HETEROPHIC DINOFLAGELLATES: FEEDING BEHAVIOR AND MECHANISMS1

The feeding of 18 species of thrcale hetrophi dinoflagellates from three genera (Protoperidininm, Oblea, Zygabikodinium) can all be described within one general framework. These species engulf diatoms and other prey with a pseudopod (herein terned a “Pallium”)which originates at the flagellar pore in the sulcus. The pallium is a highly plastic, membranous organ which rasily strethes to accommodate spines and many as 58 diatom cells in a chain. The contents of the phytoplanklon prey are liquified and transporued throughthe pallioum typically within 7 to 30 minutes of capture (although feeding may last 2 h) teaving an intact but empty cell wall or frustule. Thus far, with few exceptions, Protoperidinium specises have been observed feeding inly on diatoms, whereas two diplopsaloid species feed on dinoflagellates and prasinophytes as well. In four species from the three genera studied. a capture filament has been observed that connects the food to the dinoflagellate prior to extension of the pallium, sometimes allowing the cell to pull the food while swimming. A distinctive precapture swimming behavior is also deseribed foe six species, suggesting that the dinoflagellates are selective grazers.     

十齿花属分类地位的研究

本文对过去认为与十齿花属近缘的科,属的形态,木材解剖,花粉形态等方面的特征进行了较全面的比较研究。结果支持最初作者置于卫矛科的意见,并建立十齿花亚科,置于卫矛亚科和雷公藤亚科之间。滇西北产者订为一所种。     

Beiträge zur Pollenmorphologie der Iridaceae und ihre Bedeutung für die Taxonomie

Fifty-five genera of the Iridaceae were pollen morphologically investigated. The particularities stated in the apertures as well as the structure and sculpture of the exine are useful characteristics for the taxonomy of the family. On the base of the results of pollen morphological investigations and considering numerous further characteristics, a new arrangement of the Iridaceae is proposed.     

广西锥属植物一新种

<正> 龙州锥 (新种) 图版1 本种与淋漓锥近缘,但本种的叶片两面无毛且同色,叶缘有锯齿状裂齿,有时为钝裂齿,网状叶脉纤细而明显,果序较短,有果较少数,壳斗及坚果较大,壳斗的鳞片被毛,覆瓦状松弛排列,可作区别特征。 乔木,高5—8米,树干胸径8—15厘米,树皮灰棕色,当年生枝浑圆,粗壮,无毛,干后近暗棕色,密生淡黄色、细圆点状皮孔;新生芽阔卵形,顶端钝,长及宽均约3毫米,芽鳞无毛或边缘有稀疏短毛。叶硬报质,卵形,椭圆形或披针形,稀倒卵形,连叶柄长8—     

Itysa and Lethia, two new genera of neotropical Iridaceae

The new genera Itysa and Lethia , of the Iridaceae, are proposed; the former with two species, I. gardneri (Bak.) Rav., from northeastern Brazil, and I. venezolensis Rav., from Venezuela, the former based on Calydorea gardneri Baker, the latter described as new. Lethia is based on Herbertia umbellata Klatt.     

内蒙古自治区上侏罗统最原始的蠼螋昆虫化石(昆虫纲:革翅目:始螋亚目)

我国上侏罗统牛津阶-基末利阶（163-150Ma)保存有完好的最原始的蠼螋昆虫化石,首次描述,分析和讨论了原始蠼螋后翅脉序特征,认为与现代生存的蠼螋后翅基本相同。因此,提出了与西方某些蠼螋昆虫分类学者不同的意见,认为始螋亚目（Aechidermaptera)应归入于革翅目（Dermaptera)之中,且视其为一个最原始的类群较为合理,内蒙古自治区这个原始类群的下列重要特征皆为首次发现;胸骨具有特殊的形态结构;革翅锁具（Tegmina locking device)和刺脊突（spiny crest)发育;前,中,后足跗节皆为5节;后足基节显著伸长;颈部被划分为前,后两个颈片;革翅后缘收缩变尖,上述5项被视为厚原始蠼螋特有的祖征,下列特征应为早期蠼螋共有的原始性状;虫体扁平,通常具毛;腹部侧缘彼此近平行;触角显长,丝状,多节（通常多于11节）;两只单眼发育;上颚具齿;中胸小盾片显大;革翅较长,通常具有明显的翅脉;股节具隆脊;爪和爪垫通常发育;腹部各节背板与腹板不重叠（两者位置非简单的上,下关系）;尾须柔软,多节,雌性产卵器鞘显著外伸,本文建立了始螋亚目1新科Sinopalaeo-dermatidae和2新属2新种Sinopalaeodermata neimonggolensis gen.et sp.nov,Jurassimedeola orientalis gen,et sp.nov。同时,对蠼螋昆虫的起源和演化重新进行了讨论,做出了与西方某些蠼螋昆虫研究者结论不同的推断。