52 THE FLORA OF THE ALPS 



by the agency of insects, the pollen of the long-styled 

 plants being deposited on the stigma of the short-styled 

 plants, and vice versa. Other examples of a similar 

 heterostyly are presented by Oxalis, Lythrum, and Put- 

 monaria. Several of the yellow - flowered species of 

 Primula are familiar meadow or hedge-row plants ; all 

 the rest are more or less alpine, and are especially char- 

 acteristic of the range south of the Rhone Valley ; the 

 number of species in Northern Switzerland being com- 

 paratively small, and in the Pyrenees still smaller. 



A. Flowers yellow: P. vulgaris, Huds. (acaulis, L.), 

 Primrose; common. P. veris (pfficinalis^ Jacq.), Cowslip, 

 Paigle; frequent. P. elatior, Jacq., Oxlip; distinguished 

 by the open throat of the corolla, and the flowers being 

 rather larger and paler than those of the Cowslip ; very 

 local in England, much the more common on the Conti- 

 nent. P. Auricula, L., the Auricula; flowers fragrant, 

 leaves glabrous, upper side of the leaves, leaf-stalk, calyx, 

 and throat of the corolla covered with white meal ; local ; 

 Switzerland, Jura, Dauphiny, Pyrenees, Carpathians. P. 

 Balbisii, Lehm. ; flowers scentless, leaves with a few 

 glandular hairs, calyx usually not mealy ; Tirol, very 

 rare (Monte Baldo). 



B. Flowers red or violet, rarely white; leaves mealy 

 beneath or on the margin: P. farinosa, L. (PL 71), 

 Bird's-eye Primrose; corolla-tube somewhat longer than 

 calyx, calyx-teeth ovate, scape 2-6 in. ; damp meadows ; 

 one of the commonest and prettiest of the sub-alpine 

 plants. P. longiflora, All. (PL 72); flowers much 

 larger, corolla-tube three times as long as corolla, calyx- 

 teeth lanceolate; alpine pastures; local. P. venusta, 

 Host. ; calyx and throat of corolla mealy, leaves obovate, 



