42 Indigenous and Introduced Species. 



CHAPTER XIII. 



INDIGENOUS AND INTRODUCED SPECIES. 



In a large continent like Australia, where so many plants have been 

 introduced, both for economic and ornamental purposes, it is not always 

 easy to determine what rust-fungi are native to the country, and those that 

 have been introduced on imported plants. A plant may be indigenous, 

 and yet the rust upon it may have been derived from an allied species, as 

 in the case of P. thuemeni on native celery (Apium fro stratum) which was 

 possibly introduced with cultivated celery (Apium gravtolens), P. menthae 

 on native minit introduced upon cultivated mint, and Melampsora 

 lint, on. native and cultivated flax. On the other hand, species 

 of rust occur on well-known imparted plants, such as the daisy, groundsel, 

 and marigold, which are not recorded elsewhere, and the natural conclusion 

 is that they are indigenous, or have been overlooked elsewhere. It is only 

 in raire cases that the first introduction of any species of fungus is observed 

 and accurately determined, so that we must fall back upon some well 

 recognised principle to settle whether a rust is indigenous or not. Where 

 a new species is found on a native plant, it may be taken for granted that 

 it is indigenous, and even where the species is already known, but the plant 

 has a wide distribution, such as Phragmites communis, then there is no 

 reason to doubt that a rust upon it, such as Puccinia magnusiana is also 

 indigenous. The great majority of the rusts here recorded are, of course, 

 native, and it will only be necessary to single out those which have, in all 

 probability, been imported firom other countries. 



The following species may be regarded as having been introduced on 

 the grounds indicated* : 



Puccinia anthoxanthi Fckl. on Anthoxanrthum odoratum (1896). 

 P. arenariae (Schum.), Schroet. on Stellaria media (1896). 

 P. beckmanniae n. sp. on Beckmannia erucaefarmis (1904). 

 P. chrysanthemi Roze, on Chrysanthemum indicum (1904). 

 P. cichorii (DC.) Bell., on Cichorium intybus (1885). 

 P. cvani (Schleich.) Pass, on Centaurea cyanus (1904). 

 P. festucae Plowr. on Festuca pratensis (1903). 

 P. graminis Pers. on Wheat, &c. (1825). 

 P. helianthi Schwein. on Helianthus annuus (1887). 

 P. hypochoeridis Oud. on Hypochoeris radicata (1889). 

 P. impatientis (Schw.) Arthur, on Elymus condensatus (1903). 

 P. lolii Niels, on Lolium perenne (1896). 

 P. malvacearum Mont, on Malva, &c. (1857). 

 P. maydis Bereng. on Maize (1880). 

 P. menthae Pers. on Mentha laxiflora (1884). 

 P. poarum Niels, on Poa annua (1890). 

 P. prenanthis (Pers.), Lindr. on Lactuca sp. (1892). 

 P. pruni Pers. on Prunus sp. (1883). 



P. purpurea Cooke, on Sorghum halepense and S. vulgare (1892). 

 P. simplex (Koern.), Eriks. and Henn. on Barley (1902). 

 P. thuemeni (Thuem.) McAlp. on Apium graveolens and A. pros- 

 tratum (1892). 



P. triticina Eriks. on Wheat (probably 182^). 

 Uromyces appendiculatus (Pers.). Link! on Vigna catiano- (100=;) 

 U. betae (Pers.), Kuehn, on Beta vulgaris (1878). 



The year in brackets indicates wten first recorded for or observed in Australia"! 



