John W. Baxter

A Monograph of the Genus Uropyxis

The genus Uropyxis was erected by Schroeter (7) in 1875, based on Uropyxis amorphae (Curt.) Schroet., a rust previously treated as a species of Puccinia but differing from other species of that genus in having two pores in each cell of the teliospore. In 1897 the known species of Uropyxis were transferred to Puccinia by Dietel (5). Later the genus Uropyxis was reinstated by Magnus (6). The presence of two pores in each cell of the teliospore serves to distinguish Uropyxis from Puccinia. In addition to this character, Uropyxis is now known to possess subcuticular spermagonia and uredinoid aecia. These spermagonial and aecial characters separate it from Cumminsiella. Uropyxis differs from Phragmopyxis in aecial characteristics, in the number of cells in the teliospore and in the number of pores in each teliospore cell. Of the thirteen known species of Uropyxis, ten occur on members of the Leguminosae in North America, South America and Africa; one parasitizes a member of the Cucurbitaceae in Formosa and two occur on Bignoniaceae in South America. The latter two rusts, Uropyxis rickiana Magn. and Uropyxis reticulata Cumm., differ from other species of the genus in showing no distinct lamination in the teliospore wall. The aecial and spermagonial stages of U. rickiana and U. reticulata are unknown. In the present study these two species are included in Uropyxis with some uncertainty. In separating species or groups of species in the key, the most useful characters have been found to be the thickness, sculpturing and lamination of the teliospore wall and the length and width of the teliospore pedicel. There is considerable variation throughout the genus with respect to width of the teliospore pedicel, because of the fact that in

The Genus Cumminsiella

The genus Cumminsiella was established by Arthur (1) to segregate from the genus Uropyxis those species having subepidermal spermagonia and aecidioid aecia. The species transferred by Arthur were Uropyxis texana (Holw. & Long) Arth., Uropyxis wootoniana Arth. and Uropyxis sanguinea Arth., the last-named rust being chosen as the type of the new genus. Subsequent to Arthurs publication a new species of Cumminsiella was described by Cummins (2). In the present paper two additional species are added by the transfer of Uropyxis antarctica (Speg.) Lindquist and Uropyxis stolpiana (Diet & Neg.) Magn. Cumminsiella resembles Puccinia in having subepidermal spermagonia and aecidioid aecia, but differs in having 2 pores in each cell of the teliospore. The latter character indicates relationship with Uropyxis. With regard to spermagonial and aecial characters Cumminsiella is distinct from Uropyxis, which has subcuticular spermagonia and uredinoid aecia. Paraphysate uredia occur in one of the six known species of Cumminsiella. In two of the species sporogenous basal cells are present in the uredia. The urediospores in Cumminsiella are relatively thick-walled, with pores in zones or scattered. The urediospore wall bears closely set, conical, sharp-pointed tubercles, a type of sculpturing herein described as verrucose-echinulate. In the teliospore, as pointed out by Magnus (6), there is some variability in the position of the pores, particularly in the upper cell, in which one of the pores may be apical. All six species of Cumminsiella known at present occur on the Berberidaceae in North America, South America and Europe. The single species reported from Europe, Cumminsiella mirabilissima (Pk.) Nannf.,

Aquatic hyphomycetes of Wisconsin: Distribution and ecology

1. Eighteen species in fourteen genera of aquatic hyphomycetes were found in a survey of Wisconsin streams and lakes. No clear pattern of geographic distribution was evident but several species were more frequently encountered in northern areas. 2. Moderate to swift currents were found to support the most abundant growth and greatest variety of species. Type of bottom and relative water temperature showed no detectable effect. 3. Most of the commonly-occurring species were indifferent to the oxygen regime. Nitrogen levels did not appear to affect the abundance of these fungi and no pH preference was discernible throughout the relatively narrow range that was recorded. 4. Carbon dioxide level and abundance of aquatic hyphomycetes varied inversely. Total hardness and total alkalinity appeared to have a limiting effect at concentrations in excess of 250 ppm.

The Autoecious Species of Puccinia on North American Eupatoriae

Nineteen species and 3 varieties are recognized. Three new species are described: Puccinia potosina on Eupatorium1 longifolium in Mexico, P. sinaloana on Eupatorium sagittatum in Mexico, and P. obesiseptata on Eupatorium sp. in Mexico. The varieties are: P. kuhn iae var. robusta var. nov. on Brickellia and Kuhnia spp., P. kuhniae var. decora (Diet. & Holw.) comb. nov. (Puccinia decora Diet. & Holw.) on Brickellia sp., and P. conoclinii var. depressipora var. nov. on Piqiueria standleyi. P. eupatorii is reported for North America. A key to the species is provided and photomicrographs of type material are provided for 18 species.

A Study of Three African Species of Ravenelia on Cassia

Carroll, G. 1967. The fine structure of the ascus septum in Ascodesmus sphaerospora and Saccobolus kerverni. Mycologia 59: 527-532. Blanchard, R. 0. 1972. Septa in Sporomia australis. Mycologia 64: 1330-1333. Gull, K. 1978. Form and function of septa in filamentous fungi. Pp. 78-93. In: The filamentous fungi, Vol. 3, Developmental mycology. Eds., J. E. Smith and D. R. Berry. John Wiley and Sons, New York. Hoch, H. C. 1977. Use of permanganate to increase electron opacity of fungal walls. Mycologia 69: 1209-1213. Kimbrough, J. W., and G. L. Benny. 1978. The fine structure of ascus development in Lasiobolus monascus (Pezizales). Canad. J. Bot. 56: 862-872. Moore, R. T. 1977. Regnum fungi and the place of septal fine structure in fungal taxonomy. P. 449. In: Second International Mycological Congress Abstracts, Vol. M-Z. Eds., H. E. Bigelow and E. G. Simmons. IMC-2, Inc., Tampa, Fla. %-. 1978. Taxonomic significance of septal ultrastructure with particular reference to the jelly fungi. Mycologia 70: 1007-1024. Patton, A. M., and R. Marchant. 1978. A mathematical analysis of dolipore/ parenthesome structure in Basidiomycetes. J. Gen. Microbiol. 109: 335-349. Reynolds, E. S. 1963. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell. Biol. 17: 208-212. Samuelson, D. A., and J. W. Kimbrough. 1978. Asci of the Pezizales IV: The apical apparatus of Thelebolus. Bot. Gas. (Crawfordsville) 139: 346-361. Trinci, A. P. J., and A. J. Collinge. 1973. Structure and plugging of septa of wild type and spreading colonial mutants of Ncurospora crassa. Arch. Mikrobiol. 91: 355-364. Tu, C. C., and J. W. Kimbrough. 1978. Systematics and phylogeny of fungi in the Rhizoctonia complex. Bot. Gaz. (Crawfordsville) 139: 454-466.

Studies of Mexican Species of Ravenelia

1. Cailleux, R. 1972. Mycoflore du compost destine a la culture du champignon de couche. Rev. Mycol. (Paris) 37: 14-35. 2. Cochrane, V. W. 1958. Physiology of fungi. John Wiley and Sons, Inc. New York. 524 p. 3. Cooney, D. G., and R. Emerson. 1964. Thermophilic fungi. An account of their biology, activities, and classification. W. H. Freeman and Company, San Francisco. 188 p. 4. Evans, H. C. 1971. Thermophilous fungi of coal spoil tips II. Occurrence, distribution and temperature relationships. Trans. Brit. AMcol. Soc. 57: 255-266.

Studies of North American Species of Ravenelia

This paper presents a taxonomic study of 9 species of Ravenelia occurring on Cassia, Mimosa and Brongniartia in North America. Ravenelia fragrans Long, R. mimosae-sensitivae P. Henn., R. mesillana Ell. & Barth. and R. arthuri Long are redescribed. R. miinosae-albidae Diet., R. mimosae-caeruleae Diet. and R. mimosicola Arth. are reduced to synonymy with R. mimosae-sensitivae, and R. cassiae-covesii Long & Goodd. is reduced to synonymy with R. mesillana. This paper also describes a new species of Ravenelia on Brongniartia sp. from Sinaloa, Mexico and a new variety of R. fragrans. Most of the specimens examined during this study were obtained from the Arthur Herbarium. Purdue University, and included material recently collected by Dr. G. B. Cummins in the southwestern United States and Mexico.

NORTH AMERICAN SPECIES OF PUCCINIA ON HYPTIS

This paper reviews the species of Puccinia parasitizing hosts of the genus Hyptis in North America. It is a continuation of a taxonomic study of the rust fungi occurring on members of the family Labiatae throughout the world. Baxter and Cummins in 1951 (3), Baxter in 1953 (1), and Baxter in 1955 (2) presented taxonomic treatments of the species of Puccinia known to occur on Salvia. In the present study considerable emphasis is placed on urediospore characters in separating species in the key. In discussing the species having urediospores with two equatorial or subequatorial pores, use is made of the system of urediospore types described and illustrated by Baxter and Cummins (3) in their treatment of the North American Salvia rusts. In some of the species on Hyptis, as in many of the Salvia rusts, the urediospores are radially asymmetrical. In such species the diameter and shape of an individual urediospore depend upon whether it is viewed with the pores in surface view or with the pores in lateral view.