Vegetative key to the families

Herbs with SWOLLEN NODES and opposite or rarely whorled leaves; leaves always simple with entire margins; the leaf bases often connate. Stipules mostly absent, sometimes membranous and connate Caryophyllaceae
Sepals connate
Styles 2. Fruit a 4-valved capsule or nut
Petals absent Scleranthus
Flowers in pairs. Calyx lobes 4, less than 1 mm long; stamens 1. Ovary pyriform in shape. Leaves linear-subulate, c. 5 mm long, sometimes clustered. Small, densely branched, perennial herb, sometimes forming a mat or cushion. Blue Mts and Otford. Roadsides and grassy banks. Fl. spring–summer. Twin-flowered Knawel Scleranthus biflorus
Flowers in clusters. Calyx lobes 5, more than 1 mm long; stamens 5–10. Ovary ovoid in shape. Leaves crowded, 10–14 mm long, hairy at base. Annual herb with decumbent or ascending stems. Introd. from Europe and Africa. Fl. summer. Annual Knawel Scleranthus annuus