This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
This genus differs from Scilla in having hypogynous stamens, and the nerve of the perianth-segments of more than one rib. And the flowers are either white or yellow, never blue or red. Dwarf bulbous plants, the hardy ones chiefly from the Mediterranean region. Name from a bird, and milk; of obscure application. The following species are familiar, and the first three either naturalised or native in Britain.
1. O. umbellatum (fig. 254). Star of Bethlehem. - This grows about a foot high, with concave leaves green with a white stripe down the middle. Flowers white, numerous, umbellate, with slender pedicels and long bracts. May and June.
Fig. 254. Omithogalum umbellatum. (1/4 nat. size.)
3. O. nutans. - Flowers racemose, fewer than in the preceding, drooping. Filaments dilated upwards and trifid.
Perianth-segments white, with a green midrib. April and May.
4. O. pyramidale. - A tall species about 2 feet high with linear flaccid leaves and dense racemose flowers. Flowers white, with a green stripe on each petal; bracts white. A native of the South of Europe, flowering in Summer.
O. aicreum is a beautiful South African species with long spikes of bright yellow flowers, but it requires slight protection in Winter.