Notes on Mexican grasses IX. Miscellaneous chromosome numbers—3

Chromosome numbers are reported for 105 collections which represent 59 species belonging to 35 genera. For two of these genera:Blepharoneuron andTriniochloa no documented chromosome counts have been published to date. Records for the following species:Aristida arizonica, A. pansa, A. schiedeana, Blepharoneuron tricholepis, Deschampsia pringlei, Eragrostis palmeri,Leptochloa viscida, Munroa squarrosa, Panicum vaseyanum, Setaria grisebachii, andTriniochloa stipoides are the first for these taxa. Counts of 2n = 28 forAgrostis perennans, 2n = 20 forAegopogon cenchroides, 2n = 20 forBuchloË dactyloides, 2n = 54 forDigitaria filiformis, 2n = 60 and 2n = ca. 74 forEragrostis intermedia, 2n = 32 forErioneuron grandiflorum andE. pilosum, 2n = 44 forHilaria cenchroides, 2n = 38 and 2n = ca. 180 forHilaria mutica, 2n = 40 forPereilema crinitum, 2n = 28 forScleropogon brevifolius, 2n = ca. 108 forSetaria leucopila, and 2n = 36 forOplismenus burmannii are different from any published report for these species. Cytological information on Mexican material of the following ten species:Agrostis perennans, Aristida hamulosa,Bouteloua aristidoides, Eragrostis cilianensis, Sporobolus nealleyi, Tridens muticus,Digitaria filiformis, Hackelochloa granularis, Oplismenus burmannii, andPennisetum ciliare is here presented for the first time.     

A revision of the genus Oxytheca Nutt. (Polygonaceae)

The genusOxytheca of western North America and temperate South America consists of seven species which are keyed, described, discussed, illustrated, and mapped. They are divided among sect.Oxytheca, sect.Acanthoscyphus stat. & comb. nov., and sect.Neoxytheca sect. nov.Oxytheca dendroidea subsp.chilensis is given as a new combination, whileO. parishii var.cienegensis andO. parishii var.goodmaniana are described as new. The history and relationships of the genus are discussed. It is retained as distinct fromEriogonum and is thought to have arisen from the larger genus nearE. spergulinum, E. parishii, andE. apiculatum in subgenusGanysma. Cytological data indicatedn= 20.     

Taxonomic studies in the Miconieae (Melastomataceae). VI. Miconia santanana,a new species from Hispaniola

Miconia santanana, which occurs in broad-leaved forests along streams of pineland habitats in the Cordillera Central of the Dominican Republic, is described and illustrated. It is compared withM. ferruginea andM. adenocalyx, two presumed close relatives withinMiconia sect.Chaenopleura. Eco-geographic characterizations and a key are presented for these three species.     

Magnolia (Magnoliaceae) in Mexico and Central America: a synopsis

As a result of a recent alpha-taxonomic study of the genusMagnolia s. str. in Mexico and Central America, four new species and four new subspecies ofMagnolia sect.Theorhodon are proposed, includingM. iltisiana, M. panamensis, M. tamaulipana, M. sororum subsp.lutea, andM. pacifica, consisting of three subspecies:pacifica, pugana, andtarahumara. Additionally, a new combination,M. guatemalensis subsp.hondurensis, is made, and a new section,M. sect.Splendentes, is erected for the Caribbean species. The results have implications for understandingMagnolia biogeography, andM. tamaulipana has potential for horticulture in temperate zones. Keys to genera, sections, and species, and maps of species distributions are presented.Magnolia grandiflora L. andM. schiedeana Schltdl. are lectotypified. Como resultado de un estudio alfa-taxonómico reciente del géneroMagnolia s.str. en México y Centro América, se proponen cuatro especies nuevas y cuatro subespecies nuevas deMagnolia sect.Theorhodon, incluyendoM. iltisiana, M. panamensis, M. tamaulipana, M. sororum subsp.lutea y.M. pacifica, la última consiste de tres subespecies:pacifica, pugana ytarahumara. Adicionalmente, se hace la combinaciónM. guatemalensis subsp.hondurensis y se erigeM. sect.Splendentes para las especies del Caribe. Los hallazgos tienen implicaciones en el entendimiento de la biogeografia deMagnolia y.M. tamaulipana tiene potencial en la horticultura de zonas templadas. Se presentan claves para géneros, secciones y especies, y mapas de distribución para las especies.Magnolia grandiflora L. yM. schiedeana Schltdl. son lectotipificadas.     

Three new species of Cuphea (Lythraceae) from Mexico

Described as new areCuphea flavovirens (sect.Heterodon), C. dibrachiata (sect.Leptocalyx), andC. ownbeyi (sect.Diploptychia).     

Taxonomic studies in the Miconieae (Melastomataceae). I. Variation in inflorescence position

In the Miconieae (Melastomataceae) the inflorescences may be either lateral (with shoots pleonanthic and plants showing Rauh's architectural model) or the terminal (with shoots hapaxanthic and plants illustrating Leeuwenberg's, or less commonly Scarrone's or Stone's, architectural models). Inflorescence position is a valuable taxonomic character in the tribe and is usually uniform within genera or speciesgroups. An analysis of variation of this character elucidates the complex and difficult generic delimitations within the tribe.Ossaea DC. andClidemia D. Don, as presently delimited, contain both terminal-and axillary-flowered species and are undoubtedly polyphyletic assemblages. Some groups, e.g.,Clidemia sect.Clidemia, Leandra Raddi sect.Chaetodon Cogn.,Ossaea sect.Octopleura (Griseb.) Cogn., andMyrmidone Mart. have species that develop pseudolateral inflorescences, i.e., the terminal nature of the inflorescence is obscured by the early development of an axillary bud which continues growth of the branch. Pseudolateral inflorescences seem to have evolved several times within the tribe, andClidemia sect.Clidemia likely evolved from the obviously terminal-floweredHeterotrichum DC. andMiconia Ruíz & Pavón sect.Octomeris Hook. f. (p. p.);Myrmidone andMicrophysca Naud. are closely related toTococa Aublet; andLeandra sect.Chaetodon (and probably alsoOssea sect.Octopleura) show affinity with the remaining sections ofLeandra.     

Dragma Hippomanicum VI: A new tragacanthoid Astragalus from Nevada and Idaho

Astragalus yoder-williamsii, related toA. (sect. Neonix)peckii Piper andA. mulfordae M. E. Jones but notably different in its dwarf cespitose habit of growth and pungent leaf-stalks, is described from Humboldt County, Nevada and Owyhee County, Idaho.     

A new species of Sorghastrum (Poaceae) from Isla Socorro, Colima, Mexico

A new species ofSorghastrum,S. pohlianum, from Mexico is described and illustrated. A numerical analysis comparing the new species to the closest species (S. nutans andS. nudipes) was undertaken. The first three principal components explain 84% of the variation of the taxa involved. In addition there is morphological evidence to distinguish the new species from its closest relatives. It differs fromS. nutans by showing smaller inflorescences, having sterile lemmas and anthers, and having somewhat smaller but wider blades and different flowering periods. In addition, it is distinguished fromS. nudipes due to the presence of auricles > 1 mm long and inflorescence branches bearing spikelets along their entire length.     

Embryology of JapaneseMitella (Saxifragaceae) and its taxonomic significance

The embryo sac formation, endosperm formation, and embryo development in all species of JapaneseMitella andM. diphylla of North America were studied. Monosporic 8-nucleate embryo sac formation of thePolygonum type was found in all the species. In endosperm formation, the Cellular type was found in all species of sect.Mitellaria, and the Helobial type inM. nuda, M. diphylla, andM. integripetala. The Helobial type inM. integripetala was somewhat aberrant and approximated to the Cellular type. In embryo development, three types were distinguishable in sect.Mitellaria: Type A (most of the species), Type B (M. acerina) and Type C (M. pauciflora andM. furusei var.furusei). Type B is an intermediate type between A and C.Mitella integripetala also shows Type A, and the types ofM. nuda andM. diphylla are similar to Type A, except for the shape of suspensor. From outgroup comparison, Type A is suggested to be primitive and Type C to be most derivative in sect.Mitellaria. The affinity of some species in sect.Mitellaria is discussed from the embryogenic data obtained.     

New species of carex from Mexico and Guatemala

C.subbracteata var.tolucensis (sect.Ovales) andC. distentiformis (sect.Extensae) from Mexico,C. guatemalensis (sect.Longicaules) andC. caxinensis (sect.Viridiflorae) from Guatemala, andC. volcanica (sect.Ovales) from Mexico and Guatemala are described as new.     

Chromosome numbers of Orthocarpus and related monotypic genera (Scrophulariaceae: Subtribe castillejinae)

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.     

Two new species of Dioscorea (Dioscoreaceae) from Peru

Two new species ofDioscorea,D. gentryi (subgen.Helmia sect.Monadelpha) andD. andromedusae (subgen.Helmia sect.Centrostemon) from Peru, are described and illustrated.     

Meiotic studies in some selected members of Gamopetalae from Kashmir Himalaya

The present study is part of our research project on cytomorphology of gamopetalous flora of Kashmir Himalaya, a zone with rich biodiversity. Out of 134 species of Gamopetalae meiotically investigated, chromosome numbers for 30 accessions belonging to 17 species and six families are new or varied reports. Euphrasia paucifolia (n = 22), Lactuca decipiens (n = 8), Saussurea albescens (n = 17), Saussurea roylei (n = 16), Saussurea taraxacifolia (n = 16) and Veronica deltigera (n = 8) are first cytological reports for these species. Anaphalis nepalensis (n = 28), Codonopsis rotundifolia (n = 16) and Hieracium vulgatum (n = 27) are new euploid chromosome reports for these species suggesting potential speciation through chromosomal evolution. Besides, Androsace mucronifolia (n = 10), A. sempervivoides (n = 10), Cicerbita lessertiana (n = 8), Dracocephalum nutans (n = 5), Erigeron patentisquama (n = 9), Galium pauciflorum (n = 11), Onopordum acanthium (n = 17) and Xanthium spinosum (n = 8) are the first chromosome reports to Indian accessions of the species. Out of the 17 species, 9 species (52.9 %) viz. A. nepalensis, C. lessertiana, C. rotundifolia, D. nutans, E. patentisquama, Euphrasia paucifolia, L. decipiens, O. acanthium and V. deltigera show abnormal meiosis/microsporogenesis of one or other type, thereby leading to pollen anomalies.     

Evolution of Substrate Preparation Behaviors for Cultivation of Symbiotic Fungus in Attine Ants (Hymenoptera: Formicidae)

Despite their importance for the evolution of the symbiosis between Attine ants and their fungal cultivar, substrate preparation behaviors have been the focus of few studies. This study aimed to comparatively examining these behaviors in Acromyrmex disciger, Apterostigma pilosum, Mycetarotes parallelus, Myrmicocrypta sp., Trachymyrmex fuscus and Trachymyrmex sp. Nov. to describe the patterns of their evolution. Behavioral observations were carried out with a set of micro cameras and the behavioral frequencies were analyzed by principal components. Our findings revealed that the process can be divided into three parts: physical treatment, chemical treatment, and incorporation. Two behavioral patterns were revealed. The first is exhibited by basal species (Myrmicocrypta sp, A. pilosum and M. parallelus) and is characterized by the absence or low frequency of chemical treatment behaviors, while the second pattern is exhibited by derived species (Trachymyrmex sp. Nov., T. fuscus and A. disciger) and is characterized by great fragmentation of the substrate and deposit of fecal fluid. This suggests that the evolution of the process is marked by an increase in the importance of the chemical treatment, leading to the adaptations observed in leaf-cutting ants.     

Karyological and taxonomic observations onDracocephalum foetidum Bunge andKoenigia islandica L.

Chromosome numbers are reported for two Mongolian species,Dracocephalum foetidum Bunge (2n=12) andKoenigia islandica L. (2n=14). The relationship ofD. foetidum toD. moldavica L. (2n=10) and some patterns of phenotypic variation inK. islandica are briefly discussed. The following new combinations are proposed:K. cyanadra (Diels) Měsí?ek etSoják,K. forrestii (Diels) Měsí?ek etSoják,K. hubertii (Lingelsh.) Měsí?ek etSoják, andK. nummularifolia (Meisn.) Měsí?ek etSoják.