George B. Cummins

Morphology of the spermogonia of the rust fungi

1. The morphology of the spermogonia of 136 species in 68 genera was studied in free-hand and microtome sections.2. Presence and absence of bounding structure, shape of the hymenium, position in th...

Uredinales of New Guinea III.

On Amnomum (Hornstedia) sp., Kajabit Mission, Aug. 16, 1939 (10583), Dec. 8, 1939 (10861). On Zingiberaceae (probably Almomum), Wareo, Dec. 26, 1935 (1370), Jan. 3, 1936 (1479), Jan. 10, 1936 (1609), Jan. 12, 1936 (1662). In 1934 Mains (Ann. Myc. 32: 256-258) concluded that the genus Schroeteriaster was closely related to Uromyces. Descriptions of the telia of S. Elettariae indicate that the species is a Phakopsora.

Uredinales Parasitizing Grasses of the Tribe Chlorideae

A taxonomic account of the 27 species of rusts (Uredinales) parasitizing grasses of the tribe Chlorideae throughout the world is presented in this paper. Only Puccinia and Uromyces of the six genera of rusts known to occur on grasses parasitize species of the Chlorideae. The Chlorideae and their rusts are generally tropical or subtropical in distri? bution. However, the distribution of a particular rust usually is not as great as that of its host or hosts. Some rust species are endemic to small areas although their hosts grow over wide areas, i.e. Puccinia kansensis, while other species are cosmopolitan with their hosts, i.e. Puccinia cynodontis. Out of a total of 27 species, 17 occur in North America, 14 in South America, and 9 in Africa. Two species are known in Europe, three in Asia, and two in Australia. The Sydows monograph (20, 22) is the only previous treatment of this group on a world-wide basis. This work included 14 of the present 27 species. Publications limited geographically have included several of the presently recognized species. Arthur (3) included 13 of the species of Puccinia in the genus Dicaeoma and four of the species of

The Taxonomic Significance of Sporogenous Basal Cells in the Uredinales

The development of teliospores in clusters on basal cells was recognized by Juel (3) when he established the genus Chaconia. The genus Olivea Arth. develops similarly. Mains (6), in establishing the genus Scopella, utilized the presence of well-developed, laterally free basal cells as a characteristic of primary significance. The genus Scopellopsis, established by Ramakrishnan and Ramakrishnan (9), was segregated from Maravalia because of the presence of basal cells and paraphyses. In this method of sporulation the spores develop successively from a basal cell. Consequently, the spores in any one cluster are of unlike ages, as pointed out by Juel (3). In the genus Puccinia Kuhnholtz-Lordat (4) has designated this method of development as the fasciculate type. It is frequently difficult to demonstrate the method of sporulation with certainty. In the telia of Maravalia achroa (Syd.) Arth. & Cumm., Scopella cryptostegiae (Vestergr.) Cumm., Puccinia solmsii P. Henn., P. bottomleyae Doidge, and Xenostele indica Trium. the basal cells are not conspicuously elongate and consequently are easily overlooked. This is not the case with Scopella echinulata (Niessl) Mains, Sorataea amiciae Syd., Hapalophrag-

Phragmidium species of North America : Differential teliospore and aecial characters

Differential teliospore characters of the nineteen species of Phragmidium in North America are used herein as a basis for arranging the species occurring on the three host tribes, Potentilleae, Rubeae and Roseae, under the two sections of the genus Phragmidium, Earlea, characterized by firm non-hygroscopic teliospore pedicels, and Euphragmidium, characterized by hygroscopic teliospore pedicels. Aecial characters and teliospore char? acters are used as bases for keys to the species on each of the three host tribes. For host range and geographic distribution of each species the reader is referred to the North American Flora (3). Measurements are included where they are useful and when pertaining to teliospores do not include the pedicels. The first comprehensive study of the rust genus Phragmidium was published by Dietel (4) in 1904. In this paper he recognized seventeen species in North America and of this number thirteen are accepted as valid today. Arthur (1), in 1906, erected the genus Earlea to provide for those species which lacked uredinia in the life-cycle and in 1912 followed the same arrangement in the North American Flora (3). In subsequent works by Sydow (6) and Dietel (5) this separation into two genera was not accepted.

Nomenclatural Changes for Some North American Uredinales

The following nomenclatural changes are necessary to bring the names of certain species of North American rust fungi into accordance with the International Code.2 Most of the changes involve either: 1, the provision of Latin descriptions for telial stages which were previously, but subsequent to January 1, 1935, published in English where a specific epithet based on an imperfect stage was treated as a transfer (technically nomina nuda) or 2, names used under a perfect genus but based on the aecial or uredial stage (anticipatory names). In the first case Latin descriptions are necessary to validate the names and in the second case transfer of the specific epithet to the appropriate form genus is required. Names in common usage have been retained wherever possible.

Uredinales from the Northwest Himalaya.

The rusts reported in this paper were collected by Dr. R. R. Stewart or by R. R. and I. D. Stewart in the northern part of the United Provinces and in the Punjab, Kashmir and the Northwest Frontier Province of India. For an account of an early collection by Stewart from this region see Arthur and Cummins (Mycologia 25: 397-406. 1933). Species marked with an asterisk represent new records for India.

Notes on some species of the Uredinales.

While studying a collection of rusts on some species of Dioscorea from the Philippine Islands sections were made of specimens of this species as represented in the Arthur Herbarium. One speci? men was collected by P. W. Graff at Manila, Luzon, P. L, Dec. 2, 1912, and issued by Sydow in his Fungi Exotici as no. 230. The other was collected at Bangai village, Samoa, June and July 1926, by H. E. Parks as no. 8558. Both are on Dioscorea alata. The uredia in GrafFs collection are deep in the tissue of the leaf, apparently located about midway between the upper and lower epidermis and thus agree with the description given by Raciborski (13) for Uredo Dioscoreae-alatae. In Parks collection the uredia are just beneath the lower epidermis. The urediospores correspond closely in both collections and despite the difference in the position of the sori the two collections certainly belong to the same species. Highly gelatinized telia (fig. \,2A) are present in abundance in both collections. These telia are subepidermal in origin and show young spores almost as soon as the development has progressed to a point where the primordial sorus can be differentiated

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.

The Autoecious Species of Puccinia and Uromyces on North American Senecioneae

Uromyces senecionicola Arth., Puccinia conglomerata (Strauss) Roehling (P. syngenesarum Link, P. nardosmiae Ell. & Ev., P. petasites Vestergr.), P. glomerata Grev. (P. expansa Link), P. grindeliae Peck, P. hieracii (Mart.) Roehling (P. arnicalis Peck)., P. melampodii Diet. & Holw. (P. emiliae P. Henn.), P. recedens P. Sydow & H. Sydow, P. schistocarphae H. S. Jacks. & Holw., P. senecionicola Arth., P. senecionis Libert (P. subcircinata Ell. & Ev.) are redescribed and illustrated. Host plants in Senecioneae and the North American distribution are given for each species.