Genista radiata (southern Europe)
Habit: Compact, densely bushy dwarf shrub, 0.4-0.8 m tall, somewhat wider than tall; with thorn-less, evergreen twigs that extend far out, slow-growing.
Flowers: In terminal heads, yellow (May) June.
Leaves: Linear, in threes, only on shrub briefly.
Roots: Deep roots, collect nitrogen.
Demands: Full sun; tolerates heat and drought, frost hardy, occasional twig damage.
Soil: On all well drained, mineral substrates, slightly acidic to very alkaline; dry to fresh.
Hardiness: Zone 6b