Other prominent species are Campanula, Pyrethrum, aconite, Cephaelis, speedwell, Alchemilla sericea, Centaurea macrocephala, Primula grandis and a species of primrose.
Of four genera which Hooker singles out as the largest in Sikkim, in China Corydalis has 76 species, Saxifraga 58, Pedicularis 129, and Primula 77.
Thus the seeds of Primula japonica, though sown under precisely similar conditions, yet come up at very irregular intervals of time.
For instance, in Primula and Linum some flowers have long stamens and a pistil with a short style, the others having short stamens and a pistil with a long style.
Similar phenomenon is seen in two r widely separated genera of flowering plants: Primula Auricula and Gunnera (Halorageae).
When the ovary is situated on the centre of the receptacle, free from the other whorls, so that its base is above the insertion of the stamens, it is termed superior, as in Lychnis, Primula (fig.
Cross pollination is often favoured by dimorphism of the flower, as shown in species of Primula (fig.
Sylvestris; Phloxes, like P. subulata, with its varieties setacea, Nelsoni, nivalis; the single-flowered varieties of the Primrose, Primula vulgaris; the Polyanthuses; Pyrethrum Parthenium aureum, called Golden Feather; Sempervivum calcareum; the pinkflowered Silene pendula; self-coloured varieties of the Pansy, V.