**Description:**
– Plants of Cytisus scoparius typically grow 1–3 meters tall, rarely up to 4m, with main stems up to 5cm thick.
– Stems are ridged and green.
– Shrubs have green shoots with small deciduous trifoliate leaves 5–15mm long.
– In spring and summer, they are covered in profuse golden yellow flowers 20–30mm long and 15–20mm wide.
– Seed pods mature black, 2–3cm long, 8mm broad, and 2–3mm thick.
**Phytochemicals:**
– Main alkaloid of the plant is cytisine.
– Characteristic constituents include biogenic amines, flavonoids, isoflavones, and allelopathic quinolizidine alkaloids.
– These compounds defend the plant against insect infestation and herbivores.
– The plant has a symbiotic relationship with Rhizobium bacteria.
– Exception of the resistant aphid species Aphis cytisorum.
**Classification:**
– Two subspecies of Cytisus scoparius are: Cytisus scoparius subsp. scoparius and Cytisus scoparius subsp. maritimus.
– The latter is found in Western European maritime cliffs and associated environments.
**Distribution and Habitat:**
– Native to western and central Europe, common in Great Britain and Ireland.
– Found in sunny, dry, sandy soils at low altitudes.
– Tolerates acidic soil conditions.
– Considered an ecologically destructive invasive species in various habitats.
– Outside its native range, it colonizes grassland, shrub, woodland, and other habitats.
**Ecology and Impact:**
– Broom is invasive in North America and other countries.
– Estimated to cause significant losses in timber production in Oregon and New Zealand.
– Methods to remove broom include cutting, pulling, burning, herbicide, or introducing chickens and goats.
– Repeated treatments are often necessary due to regrowth.
– Cutting is effective in drought areas, while pulling is preferred in cooler, wetter regions.