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 present
Flowers with large bracts at the base
Bracts at base of flower scarious, straw-coloured Petrorhagia
Stems glabrous or simple-hairy. Seeds 1.3–1.8 mm long, reticulate. Widespread. Weed in pastures and waste places. Introd. from the Mediterranean. Fl. spring–summer Petrorhagia nanteuilii
Stems glandular hairy. Flowers very shortly pedicellate. Seeds up to 1.3 mm long, papillose. Weed in pastures and waste places. Introd. from the Mediterranean. Fl. spring–summer Petrorhagia velutina