Flora G. Pollack

Monosporascus Cannonballus An Unusual Ascomycete in Cantaloupe Roots

Colonies grow rapidly, and a hyaline mycelium covers the agar in a petri dish in 3-5 da at 24, 28, 35, and 38 C. Some ascocarps are produced on Difco PDA, CMA, and LBA agars. Maximum production takes place on MY agar at 28-29 C in 1 mo. The MY agar consisted of 1% malt extract, 0.4% yeast extract, and 0.4% dextrose. Ascocarps are produced on full-strength and 4-strength medium. Perithecia produced in culture are similar to those produced in cantaloupe root tissue. In culture some perithecia are so small that they contain only one or two asci, while others reach 500 /% in diam. The perithecium is nearly globose, nlembranous, cream to light brown, with a well-defined dark periapical ring (FIG. 2). Within the ring, a short, rounded neck may protrude (FIGs. 3, 4). The several-layered perithecial wall (FIG. 3) is transparent, and the dark ascospores can be seen through the wall (FIG. 1). The inner wall layers are flattened plectenchyma. The more external layers are also plectenchymatous, with pigment irregularly distributed in the walls of the outermost layers. The perithecium ruptures by a tear within the dark periapical ring (FIG. 2). Asci (FIG. 5) are clavate to pyriform, stipitate, unitunicate, thick walled, persistent, 5690 x 30-55 /u including the stipe. Asci are released from the perithecium i , J. 1931. M nographia Pezizinearum Riograndensium. Broteria, Sir. Bot. 346

Microfungi on Cercocarpus

Camarosporellum cercocarpi sp. nov. is described from lesions onCercocarpus ledifolius and the genus is compared withCamarosporium andNeohendersonia. Neohendersonia kickxii (Westend.) comb. nov., type species of the genus is redescribed and illustrated. The genusSeptogloeum is reviewed and compared withPhloeospora, andPhloeospora cercocarpi (Bonar) comb. nov. (≡Septogloeum cercocarpi Bonar) is redescribed. Conidial ontogeny is stressed as a valuable taxonomic character to be used in distinguishing between genera.

Cercospora Uromycestri, Hyperparasite of Rust on Cestrum Diurnum

Cestrum diurnum L. (jessamine) leaves, parasitized by the rust Uromyces cestri Mont., were collected in Miami, Florida, by Plant Quarantine Inspector F. D. Matthews in Oct. and Nov., 1969. The sori of Uromyces cestri formed in small, well-defined swollen areas on both surfaces of leaves and these swellings were covered by a thick, dark, felt-like layer of conidiophores and conidia of a Cercospora. Hyphae of the hyperparasite formed dark stromatic patches along the inner walls of the sori. FIG. 1 shows a normal aecium and FIGS. 2-3 show parasitized aecia. Hyphae also grew among the aeciospores, perforating them and turning the bright orange spores to dark brown. FIG. 4. All specimens of Uromyces cestri on all species of Cestrum in the National Fungus Collections were then examined to determine whether this hyperparasite was present. Only one specimen of rust was found parasitized and this was on an earlier (1964) collection of Cestrum diurnum from Miami.