RUSTS ON COMPOSITAE FROM MEXICO.

J. C. ARTHUR.

THE following enumeration of two hundred collections of Mexican rusts on Compositae comprises part of Mr. E. W. D. HOLWAY'S material obtained on his several trips into Mexico, not heretofore published; together with two specimens collected by C. G. PRINGLE, communicated by Mr. HOLWAY; two by ROSE and PAINTER, communicated by Dr. J. N. ROSE; one by E. W. NELSON, communicated by Dr. W. G. FARLOW; and one by SELER, found in the phanerogamic herbarium of the N. Y. Botanical Garden. Of the fifty-four species in the list it has been found necessary to describe eighteen as new.

It is interesting to note that the genus Puccinia embraces threefourths of all the species, and the genus Coleosporium one-half of the remaining number. Two new species are described under Dietelia, with some misgivings. Both of them are accompanied with spermogonia, and are devoid of a peridium. Whether these differences should constitute valid ground for separation into a new genus is problematical without further knowledge of their life histories and affinities. Cronartium, Pucciniosira, Uredo, and Ecidium with one species each, and Uromyces with two species are the remaining genera.

The present communication is another illustration of Mr. HOLWAY'S skill as a collector, and his service in making known the Mexican rust flora.

I. COLEOSPORIUM VIGUIERAE Diet. and Holw.

On Viguiera helianthoides HBK., Tehuacan, Nov. 18, 1903, no. 5355; V. dentata Spreng., City of Mexico, Oct. 14, 1898, no. 3055.

2. COLEOSPORIUM VERBESINAE Diet. and Holw.

On Verbesina virgata Cav., Oaxaca, Oct. 21, 1899, no. 3711; Cuernavaca, Oct. 30, 1903, no. 5298; Amecameca, Nov. 20, 1903, no. 5427: V. montanoifolia Rob. & Greenm., Patzcuaro, Oct. 19, 1898: V. pinnatifida Cav., Oct. 1896.

3. COLEOSPORIUM ANCEPS Diet. and Holw.

On Verbesina sphaerocephala A. Gr., Sayula, State of Jalisco, Oct. 7, 1903, no. 5124; Zapotlan, State of Jalisco, Oct. 10, 1903, no. 5145.

4. COLEOSPORIUM SOLIDAGINIS (Schw.) Thuem.

On Aster pauciflorus Nutt., City of Mexico, Oct. 10, 1898, no. 3071 a.

5. COLEOSPORIUM PARAPHYSATUM Diet. and Holw.

On Liabum discolor Benth. and Hook., Guadalajara, Sept. 28, 1903, no. 5062. 6. Coleosporium Dahliae, n. sp.-Uredosori hypophyllous, irregularly scattered, round, 0.5mm across or less, soon naked, pulverulent; uredospores irregularly ellipsoid, 16-22 by 24-30μ, wall colorless, rather thin, 24, closely and strongly verrucose: teleutosori hypophyllous, irregularly scattered, sometimes confluent, roundish, about 0.5mm across, waxy; teleutospores oblong, 18-21 by 45-70μ, rounded at both ends, early septate, bright orange-yellow fading to pale olive-yellow.

On Dahlia variabilis (W.) Desf., in city park, Guadalajara, Oct. 6, 1903, no.

5121.

7. Coleosporium Steviae, n. sp.-Uredosori hypophyllous, scattered unevenly and often thickly, round, 0.25-0.5mm across, early naked, pulverulent; uredospores ellipsoid to globoid, somewhat angular, 18-23 by 26-35μ, wall colorless, rather thin, 1.5-2μ, finely verrucose: teleutosori hypophyllous, scattered, often confluent, irregularly orbicular, 0.25-0.5mm across, waxy; teleutospores forming a single layer beneath the epidermis, cylindrical, 12-19 by 50-75μ, truncate or rounded at both ends.

On Stevia trachelioides (DC.) Hook., Nevada de Toluca, 3,000 m alt., Oct. 15, 1903, no. 5159 (type): S. rhombifolia HBK., Amecameca, Oct. 20, 1903, no. 5186; Rio Hondo, near City of Mexico, Oct. 4, 1899, no. 3565: S. viscida HBK., Santa Fé, near City of Mexico, Oct. 18, 1903, no. 5172: S. reglensis Benth., Santa Fé, near City of Mexico, Oct. 18, 1903, no. 5169: S. monardaefolia HBK., Cuernavaca, Sept. 26, 1898, no. 3014; Amecameca, Oct. 20, 1903, no. 5181: S. salicifolia Cav., Patzcuaro, Oct. 17, 1898, no. 3008; Toluca, Sept. 17, 1898, no. 3135, Sept. 4, 1903, no. 6778 (Rose & Painter); Pachuca, Oct. 27, 1903, no. 5248; Santa Fé, near City of Mexico, Oct. 18, 1903, no. 5176.

8. CRONARTIUM PRAELONGUM Wint.

On Eupatorium sp., Orizaba, Oct. 8, 1898, no. 3041.

9. Dietelia Eupatorii, n. sp.-Spermogonia amphigenous, numerous, crowded in small groups, punctiform, rather conspicuous, immersed, subepidermal, globoid, 100-150μ broad; ostiolar filaments becoming agglutinate: teleutosori hypophyllous and caulico

lous, crowded in orbicular groups, often circinating about the spermogonia, on stems causing small swellings up to 1 cm long, on discolored spots, very small, 0.2-0.3mm across, round, somewhat waxy; peridia wanting; spores ellipsoid, more or less angular from pressure, 20-25 by 24-36μ, wall golden-brown, smooth, medium thick, 1.5–2μ.

On Eupatorium patzcuarense HBK., Amecameca, Oct. 21, 1903, no. 5205 (type): Eupatorium sp., near City of Mexico, Oct. 9, 1898, no. 3033.

This and the following are the first species belonging to this genus reported from North America. They both differ from the type in the absence of a peridium, and in the presence of spermogonia. Like the type, however, they both have the sori separated from the tissues of the host by a filamentous layer of delicate, colorless hyphae. The form on Eupatorium is waxy, with smooth consolidated spores, like the type, the spores germinating in the sorus upon maturity. The form on Vernonia is not waxy, but pulverulent.

10. Dietelia Vernoniae, n. sp.-Spermogonia chiefly epiphyllous, numerous, crowded in orbicular groups, punctiform, goldenyellow becoming brown, prominent, subepidermal, depressed-globoid or somewhat conical, 130-145μ broad; central cavity large; ostiolar filaments becoming agglutinate: teleutosori hypophyllous, crowded opposite the spermogonia in annular groups of 2-7, or solitary, round, 0.5mm across, soon naked, pulverulent, ruptured epidermis noticeable; peridia wanting; teleutospores ellipsoid or globoid, more or less angular and irregular from pressure, 22-27 by 30-37; wall very pale yellow, medium thick, 1.5-2μ, closely and strongly verrucose, except a small spot at the base, tubercles somewhat deciduous.

On Vernonia (probably V. Deppiana Less.), Jalapa, Mex., Oct. 2, 1898, no. 3111.

II. PUCCINIOSIRA BRICKELLIAE Diet. and Holw.

On Brickellia secundiflora A. Gr., Pachuca, Oct. 27, 1903, no. 5249: Brickellia sp., Guadalajara, Sept. 22, 1903, no. 5020; Zapotlan, State of Jalisco, Oct. 10, 1903, no. 5144; Amecameca, Nov. 20, 1903, no. 5428.

12. UREDO PARTHENII Speg.

On Parthenium hysterophorus L., San Andres Chalchicomula, near Mt. Orizaba, Oct. 8, 1898, no. 3228.

13. ECIDIUM CLIBADII Syd.

On Clibadium arboreum J. D. Smith, Jalapa, Oct. 2, 1898, no. 3114.

14. Uromyces senecionicola, n. sp.-Teleutosori hypophyllous,

thickly scattered, irregularly roundish, 0.5mm or less across, long covered by the grayish epidermis; teleutospores obovoid, more or less angular, 20-25 by 24-36μ, obtuse or rounded at apex, narrowed at base, wall golden-brown, rather thin, 1-2μ, much thicker at apex, 3-6μ, concolorous; pedicel nearly colorless, thick, two-thirds length of spore or less.

On Senecio Roldana DC., Amecameca, Oct. 20, 1903, no. 5183 (type), Oct. 31, 1899, no. 3752: Cacalia sp., Patzcuaro, Oct. 20, 1898, no. 3182.

The morphological characters and gross appearance of this species closely resemble those of Puccinia senecionicola, except that the teleutospores are onecelled instead of two-celled. A very few uredospores were seen, which resembled those of P. senecionicola closely, except that they were quite colorless, which may have been due to weathering, or to their origin in teleutosori as an obsolescent form of spore. A single group of hypophyllous aecidia was also found, accompanied by epiphyllous spermogonia, but too old for securing accurate characterization.

15. UROMYCES CUCULLATUS Syd.

On Zexmenia sp., Iguala, Oct. 4, 1900 (C. G. Pringle): Perymenium Berlandieri DC., Amecameca, Oct. 31, 1899, no. 3753: P. verbesinoides DC., Cuernavaca, Sept. 30, 1898, no. 3116: P. Mendezii DC., Pachuca, Oct. 5, 1899, no. 3578, Oct. 28, 1903, no. 5257: P. discolor Schrad., Oaxaca, Nov. 10, 1903, no. 5362, Nov. 14, 1903, no. 5417.

16. Puccinia senecionicola, n. sp.-Uredosori amphigenous, somewhat gregarious or solitary, round, small, tardily naked, pulverulent, cinnamon-brown, ruptured epidermis noticeable; uredospores globoid, 24-27 by 25-32μ, wall cinnamon-brown, thin, sparsely and strongly echinulate, pores 2, opposite in the equator: teleutosori hypophyllous, thickly scattered and somewhat confluent, punctiform or bullate, long covered by the epidermis; teleutospores oblong or oblong-clavate, 16-27 by 42-60μ, obtuse, truncate or even rounded at apex, and often oblique, more or less narrowed at base, slightly or not constricted at septum, wall golden-brown, sometimes darker above, rather thin, little to much thickened at apex, 3-12, concolorous; pedicel short, nearly colorless.

On Senecio angulifolius DC., Amecameca, Oct. 20, 1903, no. 5189 (type), Oct. 31, 1899, no. 3762; Pachuca, Oct. 6, 1899, no. 3586, Oct. 28, 1903, no. 5254; Oaxaca, Oct. 22, 1899, no. 3714; Nevada de Toluca, 10,500ft alt., Oct. 15, 1903, no. 5162: S. sinuatus HBK., Pachuca, Oct. 28, 1903, no. 5252: Cacalia Pringlei Wats., Zapotlan, State of Jalisco, Oct. 9, 1903, no. 5143: C. ampullacea

Greenm., Pachuca, Oct. 5, 1899, no. 3572, Oct. 27, 1903, no. 5244: C. sinuata Cerv., Patzcuaro, Oct. 16, 1898, no. 3196: C. amplifolia DC., Oaxaca, Oct. 23, 1899, no. 3725: C. obtusiloba Rob: & Greenm., Cuernavaca, Sept. 30, 1899, no. 3538, Oct. 30, 1903, no. 5299; Patzcuaro, Oct. 17, 1898, no. 3171: Cacalia sp., Guadalajara, Sept. 14, 1899, no. 3417; Uruapan, Oct. 11, 1899, nos. 3617, 3618.

17. PUCCINIA TITHONIAE Diet. and Holw.

On Tithonia tubaeformis A. Gr., Acambora, Oct. 21, 1899, no. 3143; near Tula, Sept. 20, 1898, no. 3197: T. speciosa Hook., Sept. 28, 1898, no. 3119.

18. Puccinia globulifera, n. sp.-Uredosori hypophyllous, small, round, scattered, pulverulent, cinnamon-brown; uredospores globose, small, 15-18μ in diameter, wall medium thick, 2μ, cinnamonbrown, evenly and strongly echinulate, pores 2, opposite in the equator: teleutosori amphigenous, small, round, scattered, somewhat pulverulent, blackish; teleutospores oblong-globose, 22-25 by 24-32μ, semiopaque, rounded at both ends, not constricted at the septum, wall dark chocolate-brown, 3μ thick, closely and evenly aculeate with strong conical points; pedicel colorless except near the spore, slender, firm, 5-6μ thick, twice the length of the spore or longer, place of insertion indefinite, often at the septum.

On Otopappus epalaceus Pringlei Greenm., Iguala, Nov. 3, 1903, no. 5313. This species is widely different from P. Otopappi Syd., which has smooth teleutospores of the common obovate-ellipsoid form.

19. PUCCINIA ASTERIS Duby.

On Aster pauciflorus Nutt., City of Mexico, Oct. 10, 1898, no. 3071.

20. Puccinia Gymnolomiae, n. sp.-Uredosori hypophyllous, scattered, small, early naked, pulverulent, bright cinnamon-brown; uredospores globoid or obovate-globoid, 20-24 by 21-27, wall golden yellow, rather thin, 1-2, closely and strongly echinulate, pores 2, opposite, in the equator or often much lower: teleutosori hypophyllous, scattered, small, somewhat pulverulent, chestnutbrown; teleutospores elliptical, 26-30 by 36-45", rounded at both ends, which are strongly introverted and concave when dry, much constricted at the septum, wall chestnut-brown, smooth, evenly thick, 3-4, apex slightly thicker with a very low semiyhaline umbo; pedicel colorless, about once length of spore.

On Gymnolomia subflexuosa Benth. & Hook., Oaxaca, Oct. 17, 1899, no. 3645 (type): G. patens brachypoda Rob. & Greenm., Jalapa, Oct. 2, 1898, no. 3113.