POLLINATION. _Alsineæ_ has ordinary nectaries at the base of the calyx-stamens (Fig. 336): they are frequently protandrous but may often, in the absence of cross-pollination (in the less conspicuous species) pollinate themselves. Their open flowers are accessible to many kinds of insects (particularly flies and bees). _Gynodiœcious_ flowers are found in several species, and the ☿-flowers are then generally more conspicuous than the ♀-flowers. That the ♀-flowers have descended from ☿-flowers is seen by the large staminodes found in them (Fig. 363). _Arenaria peploides_ is diœcious (Fig. 363). The _Sileneæ_ are as a rule adapted for pollination by insects with long probosces--especially butterflies,--and they are frequently protandrous, so that at first the calyx-stamens open, later on the corolla-stamens, then the stigmas expand. The honey is secreted by a ring-like nectary round the base of the ovary or by nectaries at the base of the stamens. Some only blossom and emit scent at night or in the evening (_Lychnis vespertina_, _Silene nutans_, _Saponaria officinalis_) and, like other night-flowers, are of a white or pale colour. DISTRIBUTION. 1,100 species, especially in temperate climates, fewer in the colder zone, less still in the Tropics. The Paronychieæ are especially found in dry, sandy fields. USES. “Soap-root” (with _Saponin_, forming a lather in water) from _Saponaria officinalis_ was formerly officinal, and _Gypsophila struthium_. The seeds of _Agrostemma githago_ are said to be poisonous.--The following are ornamental plants: species of Pinks (_D. caryophyllus_, garden Pink, often with double flowers; _D. barbatus_, _plumarius_, _etc._). _Lychnis_, _Gypsophila_, _Silene_, _Cerastium_ (_C. tomentosum_ as edging for borders), _Saponaria officinalis_ (often coronate).--_Spergula arvensis_ is sometimes cultivated.