Scotch broom (Cytisus scoparius) is an invasive perennial shrub six to ten feet tall. Its sharply angled branches generally have five green ridges with hairs on them when young; as the branches mature the hairs fall off, and the branches become tan and lose the distinct ridges. Pods have hairs along the seams only. One or two golden yellow pea-like flowers cluster between the leaf base and stem. About half the photosynthetic (green) tissue is in the leaves and half is in twig tissue. Sometimes this species is confused with French broom (Genista monspessulana), which has pods with hairs all over them, stems that are not ridged or green, and more than eighty-five percent of its photosynthetic tissue in leaf tissue.
Found along the California coast from Monterey north to Oregon border, Scotch broom is prevalent in interior mountains of northern California on lower slopes and very prevalent in Eldorado, Nevada, and Placer counties in the Sierra Nevada foothills. It is also reported from Los Angeles and San Bernardino counties. It is common in disturbed places, such as river banks, road cuts, and forest clearcuts, but can colonize undisturbed grassland, shrubland, and open canopy forest below 4,000 feet.
Scotch broom currently occupies more than 700,000 acres in California. It displaces native plant and forage species and makes reforestation difficult. It is a strong competitor and can dominate a plant community, forming a dense monospecific stand. Seeds are toxic to ungulates. Mature shoots are unpalatable and are not used for forage except by rabbits in the seedling stage. Foliage causes digestive disorders in horses (Parsons 1992). Since Scotch broom can grow more rapidly than most trees used in forestry, it shades out tree seedlings in areas that are revegetated after tree harvest. Scotch broom burns readily and carries fire to the tree canopy, increasing both the frequency and intensity of fires (Parsons 1992). This species is difficult to control because of its substantial and long-lived seedbank.
Spartium junceum, a dicot, is a shrub that is not native to California; it was introduced from elsewhere and naturalized in the wild. It is an invasive plant and is fire prone.
It is an invasive plant. The California Invasive Plant Council classifies its potential impact on native ecosystems as high.
A spruce is a tree of the genus Picea, a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the earth. Spruces are large trees, from about 20-60 m (about 60-200 ft) tall when mature, and can be distinguished by their whorled branches and conical form. The needles, or leaves, of spruce trees are attached singly to the branches in a spiral fashion, each needle on a small, peg-like structure. The needles are shed when 4-10 years old, leaving the branches rough with the retained pegs (an easy means of distinguishing them from other similar genera, where the branches are fairly smooth).