110 



Uromycladium Leguminosae. 



red dust. It resembles U. simplex in having a single teleutospore at the 

 apex of the sporophore, with a lateral vesicle immediately below, but it 

 differs chiefly in the shape and size of the uredospores. The powdery 

 masses of teleutospores soon spread over the leaf and germinate in situ, 

 forming flakes which are easily detached. 



The spermogonia are seated on tubercles along with uredo and teleuto- 

 spores, but there may be powdery patches of both kinds of spores even on 

 the same phyllode, without spermogonia or the associated tubercles (Plate 

 XXXII., Fig. 274). This species represents one of the simplest forms of 

 the genus, in which the sporophore bears a single teleutospore with a lateral 

 colorless vesicle immediately beneath it. 



(Plate XXII., Figs. 185-189 ; Plate XXXII., Fig. 274.) 



Acacia. 

 32. Uromycladium simplex McAlp. 



O. Spermogonia ruddy-brown, crowded, minute, punctiform, arranged 

 in a circinate manner on both surfaces of phyllodes and very 

 occasionally on young branches. 



Spermatia hyaline, shortly ellipsoid, 4-5 x 3-4 p. 



Sori amphigenous, ruddy brown to dark brown, numerous, sometimes 

 arranged in groups, bullate, soon rupturing epidermis and be- 

 coming naked. 



II. Uredospores yellowish brown to golden brown, fusiform or oval, 



with hyaline apiculus, finely warted, with as many as six equatorial 

 germ-pores on one face, three being very common, 48-58 x 21-25 p. 



III. Teleutospores at first intermixed with uredospores, solitary at end 

 of sporophore and lateral vesicle immediately beneath, yellowish 

 brown, depressed globose to sub-globose, smooth, slightly thickened 

 at apex and germ-pore directly beneath, 22-25 X 25-32 n ; sporo- 

 phore fitting into a sort of socket on base of spore, hyaline, elon- 

 gated, 80 p. or longer; vesicle hyaline, globose 19-22 ^ diam. 



On phyllodes and branches of Acacia pycnantha Benth. 



Victoria Grampians, Nov., 1900 (C. French, jun.), Dec., 1900 

 (Robinson). Little River, Nov., 1902 and Jan., 1905 

 (C. French, jun.), Feb., 1905. Werribee Gorge, Dec., 1902, 

 and Nov., 1904. Malvern Gardens, near Melbourne, Sept., 

 1905. 



Very occasionally the colorless vesicle is replaced by an ordinary spore, 

 thus showing that the sporophore bears at its apex two spores, or a spore and 

 its substitute. 



The sori form numerous hemispherical pustules which may run together, 

 and during the latter part of spring and early summer, while the teleuto- 

 spores are being produced, the exuded spores are observed imbedded in gum, 

 freely germinating and readily detachable in flakes. 



The uredospores somewhat resemble those of Uromyces fusisporus, but in 

 the latter there are only 3-4 germ-pores on one face. 



The spermogonia were first found in September on a young tree about 

 four years old, and they usually occurred on distinct ruddy spots produced 

 by Coniothyrium pycnanthae McAlp. and other fungi. 



Darluca filum Cast, not uncommon on sori containing both uredo and 

 teleutospores. 



(Plate XIX., Figs. 161-165; Plate XXXII., Fig. 275.) 



