Fig. 361.—A-F Diagrams of flowers of the Caryophyllaceæ: A Agrostemma; B Sagina; C Stellaria; D Corrigiola; E Paronychia; F Herniaria.
The most original type appears to be represented by the Alsineæ. From this form on one side the Sileneæ, adapted in a higher degree for insect-pollination, are developed, and on the other side the Paronychieæ, with various reductions.
1. Alsineæ, Stitchwort Group. Sepals free, and connected with them stellately expanded, slightly unguiculate (white or inodorous) petals; these, however, often become suppressed (Fig. [363]). The fruit is a capsule.
Fig. 362.—Cerastium arvense: A fruit; B seed; C section of seed.
a. As many carpels as sepals (4 or 5). Cerastium (Chickweed). The petals are bifid. Capsule cylindrical, frequently curved at the top, and opening by 10 teeth (Fig. [362]).—Malachium differs only in the 5-toothed capsule with bifid teeth.—Spergula (Spurry). The petals are not bifid, capsule 5-valved; seeds winged. The leaves are linear, and appear as if placed in large numbers in a whorl, a branch being situated in the axil of each with leaves placed very close together at its base; stipules membranous.—Sagina has Sn, Pn, An + n, or An, Gn, where n = 4 or 5. The corolla is often wanting.
b. 3 (rarely 2) carpels (Fig. [361] C). Stellaria (Stitchwort) has deeply cleft petals. The number of stamens varies (see above).—Arenaria has entire petals. (To this group belong Alsine, Moehringia, Halianthus, or Honckenya (Fig. [363]), which differ from each other, especially in the form of the seed and number of the capsular valves.) Spergularia has membranous stipules, as in Spergula.—Holosteum.
Fig. 363.—Arenaria (Halianthus) peploides: ♀-(A) and ♂-flower (B, C).
2. Paronychieæ (Figs. [361] D, E, F; [364]). Small, greenish plants. The leaves, in the majority, are opposite, with membranous stipules. The flowers are most frequently arranged in small dichasia; they are small and insignificant, perigynous (Fig. [364]) or hypogynous. The corolla is in most cases wanting, and when present is very small; in general the calyx-stamens are developed, but the corolla-stamens may be represented by small scales (Fig. [364]). Ovary most frequently with 1 ovule. Fruit, a nut, rarely a capsule; it is enclosed by the strongly perigynous floral axis (torus).