GENERA. _Puccinia_ (Fig. 146, 147) has bicellular teleutospores, each having a germ-pore, and the æcidia when present have an indented peridium; some species, as exceptions, have 1–3-celled teleutospores. Many species are HETERŒCIOUS, for example, _P. graminis_, described above; _P. rubigo_, which also infests various Grasses, but whose æcidia appear on _Anchusa_; the masses of teleutospores are small; they contain paraphyses, and are for a long time covered by the epidermis. _P. coronata_, on Oats and Rye Grass; its æcidia on _Rhamnus_; the teleutospores are surmounted by a crown--“coronate processes.” _P. phragmitis_, on Reeds; æcidia on species of _Rumex_ and _Rheum_. _P. moliniæ_, on _Molinia cœrulea_; the æcidia on Orchids. _P. poarum_, on Meadow-Grass; æcidia on _Tussilago_. Various Puccinias growing on species of _Carex_ have their æcidia on _Urtica_, _Lysimachia_, _Cirsium_, _Pedicularis_, etc.--Of those AUTŒCIOUS species, which have all their generations on the same host, may be noted:--_P. galii_, _P. menthæ_, _P. violæ_, _P. epilobii_, _P. asparagi_, which grow on the hosts from which they have taken their specific names.--As representative of a group which have spermogonia, uredo-and teleutospores on the same host, but on different individuals, _P. suaveolens_, on the Field-Thistle, may be mentioned. The spermogonia have a strong odour.--A peculiar group (_Leptopuccinia_) has only teleutospores, which germinate immediately, and whilst still attached to their living host. To this group belong _P. arenariæ_, on a number of Caryophyllaceæ; and _P. malvacearum_, on various Malvaceæ, introduced in 1873 from South America to Europe, where it soon proved very destructive to Hollyhocks. _Uromyces_ (Fig. 149) differs only from _Puccinia_ in always having unicellular teleutospores. Among this genus both heterœcious and autœcious species are found. To the first group belong _U. pisi_, whose æcidia are found on _Euphorbia cyparissias_, and _U. dactylidis_, whose æcidia appear on _Ranunculus_; to the second group belong _U. betæ_, _U. phaseoli_, _U. trifolii_. _Triphragmium_ has teleutospores with three cells (one below and two above), on _Spiræa ulmaria_. _Phragmidium_ (Fig. 150) has teleutospores consisting of a row of cells (3–10) arranged in a straight line; the upper cell has one germ-pore and the others four germ-pores placed equatorially. Both this and the preceding genus have large, irregular æcidia without peridia, but often with bent, club-like paraphyses (150 _b_ and _c_); they are all autœcious, and are only found on the Rosaceæ. [Illustration: FIG. 148.--_Gymnosporangium sabinæ_. A small portion of the epidermis of a Pear-leaf (_a_) pierced at _b_ by the germinating basidiospore (_c_).] [Illustration: FIG. 149.--_Uromyces genisteæ_; _a_ uredospore; _b_ teleutospore.]