Showing papers in "Brittonia in 1982"
907 citations
TL;DR: The monocotyledons : a comparative study, The monocOTyledon :a comparative study, The MonocotYledons: a comparative comparative study,.
Abstract: The monocotyledons :a comparative study , The monocotyledons :a comparative study , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
330 citations
TL;DR: The Pantanal is a region on the Brazil-Bolivia frontier in the Paraguay river basin, that is predominantly but not exclusively covered by various types of swamp vegetation as mentioned in this paper.
Abstract: The Pantanal is the region on the Brazil-Bolivia frontier in the Paraguay river basin, that is predominantly but not exclusively covered by various types of swamp vegetation. The vegetation of the area was studied by extensive collecting and through measuring trees on five one-hectare plots of cerrado and semi-deciduous forest. The region consists of various types of swamp, gallery forest, lake margin scrub forest, semi-deciduous forest, and several forms of cerrado and savanna. The vegetation is made up of species derived from the cerrado of Central Brazil, the Chaco and Amazonia. It also includes many widespread but few endemic species. Little vegetation remains undisturbed due to the influence of cattle, fire and man. Good examples of the various vegetation formations can still be found and are in urgent need of conservation.
206 citations
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TL;DR: The Eocene sediments of southern Maryland and adjacent Virginia have yielded multilocular fruits assignable to the extinct genera Wetherellia Bowerbank andPalaeowetherellIA Chandler, the first report of their co-occurrence in one deposit.
Abstract: The Eocene sediments of southern Maryland and adjacent Virginia have yielded multilocular fruits assignable to the extinct generaWetherellia Bowerbank andPalaeowetherellia Chandler. This is the first report of their co-occurrence in one deposit.Wetherellia has previously been reported from the Eocene of southern England and West Germany (two species), whilePalaeowetherellia has been reported from the Eocene and possibly latest Cretaceous of Egypt (one species). APalaeowetherellia-like fruit has been reported from the Eocene of southeastern North America.Wetherellia marylandica comb. nov. andPalaeowetherellia species are described; new information is provided for the previously established speciesWetherellia variabilis andW. dixonii. The familial assignment of both genera is reviewed.Palaeowetherellia is most similar to fruits of the tribe Hippomaneae of the Euphorbiaceae, whileWetherellia finds counterparts in the Euphorbiaceae and the Meliaceae. While the exact affinities ofWetherellia are difficult to resolve through comparison to modern fruits, the similarity ofWetherellia andPalaeowetherellia might suggest that the former is more likely euphorbiaceous than meliaceous. The discovery of these New World members of both genera reinforces the importance of floristic exchange across the North Atlantic in earliest Tertiary time.
29 citations
TL;DR: Two varieties of Dion edule are recognized in the Sierra Madre Oriental, characterized by wide leaflets and a distribution in Veracruz, Hidalgo, Querétaro, San Luis Potosí and southern Tamaulipas, andD.
Abstract: Dion edule is distributed through the Sierra Madre Oriental from Veracruz to Nuevo Leon and in dijunct stations in Tamaulipas. The most significant variation consists in the reduction of leaflet width from the south northwards. On this basis, two varieties are recognized:D. edule var.edule, characterized by wide leaflets and a distribution in Veracruz, Hidalgo, Queretaro, San Luis Potosi and southern Tamaulipas, andD. edule var.angustifolium, with narrow leaflets and a distribution in central-northern Tamaulipas and Nuevo Leon.
24 citations
TL;DR: It is shown here that the structure, which has been taken for the “seed coat,” is actually the locular wall, which serves as a false seed coat in Campomanesia.
Abstract: The glandular nature of the “seed coat” has long been the most important taxonomic character defining the genusCampomanesia. It is shown here that the structure, which has been taken for the “seed coat,” is actually the locular wall. The development of the ovaries and seeds ofCampomanesia is discussed and illustrated. Three characteristics ofCampomanesia are identified as distinguishing it from other genera of the Myrtaceae: (1) the abortion of all but one ovule in each fertile locule; (2) the protective, glandular locular wall that serves as a false seed coat; and (3) the large number of locules in the ovaries. Reasoning is presented to explain the possible sequence of evolutionary origin of these three characteristics.
24 citations
TL;DR: In the course of contributing to the English-language version of a book on plant geography by Academician Armen Takhtajan, I have had occasion to prepare a map of the floristic regions and provinces of North America.
Abstract: In the course of contributing to the English-language version of a book on plant geography by Academician Armen Takhtajan, I have had occasion to prepare a map of the floristic regions and provinces of North America. I now wish to put this map on record. The map is released from copyright, but we hope that anyone who uses it will acknowledge the source. The code of numbers and letters on the map is iintended to mesh with the number-code in the book. It may be explained as follows:
TL;DR: Scanning electron microscopy of foliar surfaces of the seven species ofFraxinus native in eastern North America confirms the importance of cuticular patterns (smooth, striated, striate-papillose, and coronulate) as useful taxonomic character states.
Abstract: Scanning electron microscopy of foliar surfaces of the seven species ofFraxinus native in eastern North America confirms the importance of cuticular patterns (smooth, striated, striate-papillose, and coronulate) as useful taxonomic character states. There are there trichome types (acicular hairs ornamented with micro-striae or-papillae, peltate glands, and scales) which are found in nearly all species and which vary only in density. No differences in surface features are found by which determination can be made of either sex or ploidy level inF. americana. Hybridization betweenF. americana andF. pennsylvanica is considered to be rare in nature and is not a probable cause for the overlap of character states and concomitant difficulty of identification based upon gross morphological features. Likewise, the putative hybrid origins ofF. biltmoreana andF. profunda are not supported by micro-morphological features. Illustrations are given for all species.
TL;DR: The fern genus Anemia is represented in Mexico by 21 species and hybrids, of which five are here described as new, including A. familiaris, A. multiplex, and A. ×paraphyllitidis.
Abstract: The fern genusAnemia is represented in Mexico by 21 species and hybrids, of which five are here described as new:A. familiaris, A. multiplex. A. ×paraphyllitidis. A.×recondita andA. semihirsuta. Hybridization is frequent, resulting in both sterile and fertile hybrids, and has probably led to much recent speciation in the genus, including presumably sexual polyploids up to possibly the tetrakaidecaploid level.
TL;DR: Meiotic chromosome numbers and observations were made in eleven species belonging to nine different genera of Bambusoideae, which indicates a preponderance of polyploidy in the woody members, or bamboos, but not in their herbaceous allies.
Abstract: Meiotic chromosome numbers and observations were made in eleven species belonging to nine different genera of Bambusoideae. The numbers include counts in eight species that have never been investigated cytologically:Arundinaria aff.amabilis (n=24), Chusquea bambusoides (n=ca. 20),Cryptochloa dressleri (n=11), Olyra ciliatifolia (n=11), Sucrea monophylla (n=11), Raddia brasiliensis (n=11), Strephium distichophyllum (n=11), andPariana aurita (n=22). The generaStrephium andSucrea have not been studied previously with respect to their chromosomes. The significance of these results are discussed in relation to the over 140 published counts in the subfamily, which indicates a preponderance of polyploidy in the woody members, or bamboos, but not in their herbaceous allies. Aneuploidy is rare in the former but frequent in the latter. It is postulated that the herbaceous bambusoids, which flower every year and produce recombinants regularly and in short-time cycles, could have tolerated successive reductions of the linkage groups and their genetic flexibility. These changes would not have been favored in the bamboos, which have more genetic constancy due to the long lapse (often 20–120 years) between flowering generations.
TL;DR: This species is distinct from all others in the genus in that it has a straight rachis with very narrow leaflets which are strongly curved and almost round in cross section when dried.
Abstract: Ceratozamia norstogii sp. nov. from Chiapas, Mexico is described. This species is distinct from all others in the genus in that it has a straight rachis with very narrow leaflets (3–10 mm wide) which are strongly curved and almost round in cross section when dried. It is known only from Chiapas, Mexico and in cultivation.
TL;DR: A new genus of Convolvulaceae is described to accommodate two species previously included within Jacquemontia, and a taxonomic treatment of the new genus Odonellia is presented.
Abstract: A new genus of Convolvulaceae is described to accommodate two species previously included withinJacquemontia. A discussion is given of generic limits in the family, and a taxonomic treatment of the new genusOdonellia is presented.
TL;DR: An observation of a snake catching a bat visiting a capitulum of the chiropterophilous tree Parkia nitida is described and the implications of predator avoidance on the behavior of pollinators and hence on cross-pollination are discussed.
Abstract: An observation of a snake catching a bat visiting a capitulum of the chiropterophilous treeParkia nitida is described. The implications of predator avoidance on the behavior of pollinators and hence on cross-pollination are discussed. Fear of predation may be the reason why some bats make only brief visits toParkia capitula.
TL;DR: The genusPiresia is augmented by two new species,P.
Abstract: Two new species are added toCryptochloa,C. unispiculata from Peru andC. capillata from Brazil, the latter transferred from the genusOlyra. The genusPiresia is also augmented by two new species,P. macrophylla from Peru andP. leptophylla from Bahia, Brazil. These species represent, respectively, the westernmost and easternmost limits of distribution of the genus.
TL;DR: Daphniphyllum may form a plexus, characterized by primitive xylary and other features, comparable to Annonales (Magnoliales) as products of an early radiation of dicotyledons.
Abstract: Wood anatomy of 16 collections representing three species containing eight subspecies of the single genusDaphniphyllum is analyzed quantitatively and qualitatively.Daphniphyllum has vessels angular to roundish in transection, scalariform perforation plates, scalariform to opposite lateral wall vessel pitting, tracheids with fully bordered pits, heterocellular multiseriate and uniseriate rays, diffuse axial parenchyma and, in one taxon, chambered crystals in axial parenchyma cells. Growth rings, narrower vessels, and more numerous, vessels per square mm characterize taxa from cooler habitats. All of the taxa have highly mesomorphic woods. Comparisons are made between Daphniphyllaceae and the other families of Thorne's Pittosporales (Balanopaceae, Bruniaceae, Buxaceae, Byblidaceae, Geissolomataceae. Grubbiaceae, Myrothamnaceae, Pittosporaceae, Roridulaceae, and Tremandraceae). These families are most comparable to hamamelidoid or rosoid families; other similarities or relationships for these families may exist, but are less conspicuous or less close. The families cited may form a plexus, characterized by primitive xylary and other features, comparable to Annonales (Magnoliales) as products of an early radiation of dicotyledons.
TL;DR: The genus Leptotheca is characterized by its acrocarpous habit, lanceolate leaves with an excurrent costa and smooth, thick-walled cells, and the occurrence of uniseriate, usually papillose propagula on the upper stems.
Abstract: Leptotheca is recognized as comprising two species,L. boliviana Herzog (L. costaricensis Cardot & Ther., syn. nov.) andL. gaudichaudii Schwaegr. The latter species consists of two varieties, var.gaudichaudii and var.wattsii (Cardot) comb. nov. The genus is characterized by its acrocarpous habit, lanceolate leaves with an excurrent costa and smooth, thick-walled cells, and the occurrence of uniseriate, usually papillose propagula on the upper stems. The genus is transferred from the aulacomniaceae to the Rhizogoniaceae on the basis of gametophytic and sporophytic characters. A key to the genera of the Rhizogoniaceae is provided.
TL;DR: A listing of papers and dissertations either using some type of cladistic analysis on a plant group or dealing with theoretical cladistics and written by a botanist, and the distribution of the taxa treated in the various papers.
Abstract: A listing of papers and dissertations either using some type of cladistic analysis on a plant group or dealing with theoretical cladistics and written by a botanist. In addition, to facilitate studies in vicariance biogeography, this list includes the distribution of the taxa treated in the various papers.
TL;DR: A chromosome number ofn=12 is reported for the three monotypic genera of subtribe Castillejinae:Clevelandia beldingii, Gentrya racemosa, andOpicopephalus angustifolius.
Abstract: A chromosome number ofn=12 is reported for the three monotypic genera of subtribe Castillejinae:Clevelandia beldingii, Gentrya racemosa, andOpicopephalus angustifolius. Chromosome numbers ofOrthocarpus correspond mostly with current infrageneric classification. SubgenusTriphysaria hasn=11.Orthocarpus sectionsCastillejoides andCordylanthoides, which are closely related toCastilleja (x=12) and the three monotypic genera above, haven=12 with aneuploid reductions ton=10 inO. linearilobus andn=11 inO. lacerus (a species also withn=12). Tetraploids are found in two species.O. brevistylus (n=24) andO. hispidus (n=12, 24). The polyploid.O. laciniatus (n=36, 48) of Peru is postulated to be of hybrid origin between a species ofCastilleja andOrthocarpus attenuatus. SubgenusOrthocarpus sectionOrthocarpus, which hasn=14 in all species except.O. bracteosus (n=15), stands apart both morphologically and in chromosome number from the remainder of the genus.
TL;DR: Two previously monotypic genera,Taenidia andPseudotaenidia, are combined to form a single genus TaENidia, with two species, one of which is new to science and the other of which has previously been referred to different tribes of the Apiaceae.
Abstract: Two previously monotypic genera,Taenidia andPseudotaenidia, are combined to form a single genusTaenidia, with two species. The difference in the fruits that has caused these otherwise very similar taxa to be referred to different tribes of the Apiaceae is considered to be of only specific importance in this instance.
TL;DR: Ceratozamia kuesteriana is very closely allied to C. zaragozae Medellin but differs by not having twisted leaves as mentioned in this paper, and has been found in southern Tamaulipas.
Abstract: Ceratozamia kuesteriana Regel, which was described from material coming from an unspecified Mexican locality and which, after its description, was never recorded in the field, has been found in southern Tamaulipas.Ceratozamia kuesteriana is very closely allied toC. zaragozae Medellin but differs by not having twisted leaves.
TL;DR: The single species ofGeropogon, G. hybridus (L.) Schultz-Bip.
Abstract: The single species ofGeropogon, G. hybridus (L.) Schultz-Bip., is sometimes submerged in the morphologically similarTragopogon. A comparative study of the karyotypes ofGeropogon andTragopogon sensu stricto clarified their relationship. The karyotype ofG. hydridus (2n=14) was compared with that ofT. dubius Scop. (2n=12). The karyotypes are distinct, offering a compelling reason to recognizeGeropogon as a separate genus.
TL;DR: Two new species and one subspecies from Brazil are described and figured and the distribution, affinities and delimiting characters and prospects for a new classification of Piptocarpha are discussed.
Abstract: The distribution, affinities and delimiting characters and prospects for a new classification ofPiptocarpha are discussed. Two new species and one subspecies from Brazil are described and figured:Piptocarpha densifolia, P. ramboi andP. rotundifolia (Less.) Baker subsp.hatschbachii.
TL;DR: In this article, a survey of the palm specimens in three Brazilian herbaria (MG, IAN and INPA) was conducted to assess the state of systematic collections presently available in Amazonia, and twelve criteria were utilized to measure the quality of the specimens.
Abstract: Despite their economic and ecological importance, Amazonian palms have been largely neglected by contemporary taxonomists. The resulting confusion at the specific level is a serious impediment to research efforts by specialists in other fields. To assess the state of systematic collections presently available in Amazonia, we conducted a survey of the palm specimens in three Brazilian herbaria (MG, IAN and INPA). Twelve criteria were utilized to measure the quality of the specimens. We found that most of the 897 specimens are reasonably complete in a physical sense, but a large proportion lack crucial information on their labels. Curating facilities are in serious need of improvement, as is evident from the significant (26%) percentage of specimens found to be in an unreasonable state of preservation. A checklist of the 232 currently recognized palm species in Brazilian Amazonia shows that 145 (62.5%) are not represented by identified specimens, and that the representation which does exist lacks depth. To improve the quality and representativeness of collections in regional herbaria, we suggest procedures for collecting and storing palms as well as policies designed to intensify collecting efforts in Amazonia.
TL;DR: Eobruchia ecuatoriana sp.
Abstract: Eobruchia ecuatoriana sp. nov. (Bruchiaceae) has the aspect of a diminutiveTrematodon, but is distinctive in having a mitrate calyptra and flexuous seta;Macromitrium perreflexum sp. nov. (Orthotrichaceae) has ramarkably reflexed leaves, unlike any known species;Lepidopilum pulcherrimum sp. nov. (Hookeriaceae) is distinguished by its large size and beautifully undulate leaves;Symphyodon americanus sp. nov. (Symphyodontaceae) is remarkable in being the first American representative of a genus and family previously known only from Asia; it is most closely related toS. echinatus (Mitt.) Jaeg. of the Himalayas and Thailand.
TL;DR: Notes on morphology and chromosome numbers are given for several species of MexicanCoreopsis, most of which were poorly known prior to recent collections.
Abstract: Notes on morphology and chromosome numbers are given for several species of MexicanCoreopsis, most of which were poorly known prior to recent collections.Coreopsis parvifolia (sectionElectra) is a large, shrubby, octoploid (2n=112) species apparently restricted to a small area in Puebla. It andC. cuneifolia (a diploid with 2n=28) appear to be closely related but differ by a number of morphological features in addition to ploidy level. A first chromosome report forC. pringlei (sectionPseudoagarista) shows this rare species to be diploid (2n=26), a fact which is in agreement with the base number of the section, i.e.,x=13. Additional collections of the very rareC. rudis andC. mcvaughii show them to be similar yet distinct species. Chromosome determinations forC. petrophila from Nayarit and Durango agree with previous counts for Jalisco populations of the species, i.e., 2n=26. Considerable morphological variation exists within this species but no subspecific entities are recognized.