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.     

The correct author citation of bunchosia (Malpighiaceae) and three new Central American species

The genusBunchosia is ascribed to Humboldt, Bonpland & Kunth and should be cited asBunchosia Rich.ex H.B.K. Three new Central American species,B. brevisurcularis,B. ternata, andB. tutensis, are described, illustrated and plotted on a distribution map.     

Tres adiciones al genero Baccharis (Compositae) en Mexico

1. -Bigelowia pyramidata Rob. & Greenm. from Oaxaca proves to be a dioecious plant and is therefore transferred to the genusBaccharis.
2. -Baccharis matudae sp. nov. is described on the basis of material collected in Zacatecas and San Luis Potosí. The species is closely related toB. pyramidata (Rob. & Greenm.) Rzedowski.
3. -Baccharis zamoranensis sp. nov. is described on the basis of material collected on the border of Querétaro and Guanajuato. The taxon is related toB. multiflora H.B.K., known from central and southern Mexico.

     

Neotropical Segregates from Sida L. (Malvaceae)

Three genera are segregated out ofSida as natural units,viz. Sidastrum E. G. Baker, enlarged from one species to seven,Krapovickasia nom. nov. including four species, andRhynchosida gen. nov. including two species, one described as new from Bolivia,R. kearneyi. Mericarp and calyx morphology are emphasized in delimiting these genera and in defining the residual genusSida, which now assumes a more natural character.     

A revision of isertia (Isertieae: Rubiaceae)

A revision is presented, of the neotropical genusIsertia Schreber.Cassupa Humb. & Bonpl. is given a new status asIsertia sectionCassupa (Humb. & Bonpl.) B. M. Boom, based on differences in fruit type, number of locules in the ovary, and number of lobes of the stigma. A new combination is made at the species level,I. laevis (Triana) B. M. Boom, and a new species from Panama is described and illustrated,I. scorpioides B. M. Boom. Altogether, fourteen species and one variety are recognized in the genus.     

Notes on neotropical vaccinieae (Ericaceae). VI. New species from the cordillera vilcabamba and adjacent Eastern Peru

Thibaudia dudleyi var.dudleyi and var.pseudostellata,Demosthenesia cordifolia,D. oppositifolia, andD. vilcabambensis from the Cordillera Vilcabamba, andCavendishia sirensis from the Cerros del Sira in eastern Peru are described and illustrated. The Cordillera Vilcabamba seems to be the center of distribution for the genusDemosthenesia.     

A new species of Lasiadenia (Thymelaeaceae) from Venezuela

Lasiadenia ottohuberi from Venezuela is described and illustrated. Differences between the South American genusLasiadenia and the related Cuban genusLinodendron are discussed.     

A new species and a new combination in western North American Silene (Caryophyllaceae)

Silene nachlingerae is described, illustrated, and compared toS. aperta. The similarly floweredS. invisa is considered to be closely related toS. bernardina, and especially to its var.rigidula (Robinson) Tiehm, comb nov.     

A revision of Vernonia series Buddleiifoliae (Compositae: Vernonieae)

SeriesBuddleiifoliae of the genusVernonia of southeastern South America consists of 18 species which are keyed, described, discussed and mapped.Vernonia goiasensis is proposed as a new name, whileV. wasshausenii andV. monocephala subsp.irwinii are described as new taxa, and V.asteriflora subsp.kuntzei is presented as a new combination.     

Pranceacanthus coccineus (Acanthaceae), a new genus and species from Amazonian brazil

The new genusPranceacanthus, apparently most closely related to the bitypic genusJuruasia, is described and illustrated. Its sole species,P. coccineus, has been collected on “terra firma” in lowland Amazonian Brazil in the states of Amazonas and Mato Grosso and in the territory of Rondônia.     

A preliminary account of colura (Hepaticae,Lejeuneaceae) in Australia

Four species of Colura not previously reported from Australia are: C. acroloba (Mont.) Jovet-Ast, C. ari Steph., C. conica (Sande Lac.) Goeb., and Colura queenslandica sp. nov. A key to all ten species occurring in Australia is provided. Saccate lobules of C. simplicior are described and illustrated for the first time. The name Colura sect. Lingua Jovet-Ast ex Thiers is validated.     

New taxa of Leguminosae-Caesalpinioideae from Bahia,Brazil

Brodriguesia santosii, gen. & sp. nov., from the coastal rain forest of Bahia, is described, illustrated and compared with nearly related genera of the tribe Detarieae. In addition, three new species, Arapatiella emarginata (the second species of the genus), Swartzia oblata, S. pinheiroana and one new variety, Goniorrhachis marginata var. bahiana, are presented.     

New taxa and combinations in Malvastrum A. Gray (Malvaceae: Malveae)

The genusMalvastrum A. Gray is interpreted to include 22 taxa in 14 species. Seven taxa are here described as new, namely:M. americanum var.stellatum,M. tomentosum subsp.pautense,M. bicuspidatum subsp.campanulatum,M. bicuspidatum subsp.oaxacanum, M. bicuspidatum subsp.tumidum var.tumidum, M. bicuspidatum subsp.tumidum var.glabrum, andM. coromandelianum subsp.fryxellii. In addition, two new combinations are proposed, namely:M. tomentosum andM. coromandelianum subsp.capitato-spicatum.     

Stuessya (Asteraceae: Heliantheae), a new genus from southcentral Mexico

Stuessya, a new genus from the Pacific slopes of southcentral Mexico is described. It is comprised of three species:S. apiculata, previously assigned to the genusViguiera;S. perennans, the generotype; andS. michoacana. The latter two taxa are previously undescribed. The genus is characterized by its urceolate, sclerified (at maturity) involucre. Chromosome counts of2n = 34 are reported forS. perennans. Relationships are problematical, but are reckoned to be somewhere betweenAldama andViguiera.     

A new catostemma (Bombacaceae) from Colombia

A new tree species from Colombia, closely resembling other members of the neotropical genusCatostemma in its large one-seeded fruits, is described and illustrated.Catostemma digitata has palmately compound leaves, previously unknown in mature individuals of this genus.     

Studies on Middle American begonia (Begoniaceae) II

Begonia breedlovei, B. chiapensis, andB. jaliscana, new species in sectionGireoudia from Mexico, are described, illustrated, and discussed.     

Five new species of Heteropterys (Malpighiaceae) from Central and South America

Five-new taxa ofHeteropterys H. B. K. subsect.Aptychia Nied. are described, illustrated, and mapped:H. andina from Peru;H. minutiflora from Costa Rica; andH. bullata, H. capixaba, andH. oberdanii, from the Atlantic coastal forest of Brazil. The affinities and diagnostic characters of each species are discussed.     

Two overlooked species of Guzmania (Bromeliaceae) of the species-complex Massangea from Central America

Two new speciesGuzmania herrerae andG. scandens, that have been mistakenly identified asG. dissitiflora are described and illustrated. All three taxa belong to a natural complex of species that corresponds to the formerly recognized segregate genusMassangea E. Morren. However, without additional morphological and molecular evidence we believe it is premature to recognize this species complex as a genus separate fromGuzmania.