Seeds rarely. Increased readily by cuttings. For summer bedding in the north, cuttings should be started in February or March. For use as window plants, they should be taken in late summer.
Iriartea, Deckeria. Palmæ.
Propagation is effected by seeds.
Iris, including Xiphion. Irideæ.
Seeds grow readily and give good results, and they are usually produced freely, especially in the bulbous species. Sow as soon as ripe in light soil in some protected place. The bulbous species produce bulbels, which may be used for multiplication. The rhizomatous species are propagated by dividing the rhizome into short rooted pieces. Or when the rhizomes lie on the surface of the ground and do not root readily, they may be layered.
Isonandra (Gutta-Percha Tree). Sapotaceæ.
Insert cuttings in sandy soil, under glass, in heat.
Isoplexis, Callianassa. Scrophularineæ.
Cuttings of half-ripened shoots should be made in spring under glass.