Genisteae

Genisteae is a tribe of trees, shrubs and herbaceous plants in the subfamily Faboideae of the legume family Fabaceae. It includes a number of well-known plants including broom, lupine (lupin), gorse and laburnum.

The tribe's greatest diversity is in the Mediterranean, and most genera are native to Europe, Africa, the Canary Islands, India and southwest Asia. However, the largest genus, Lupinus, is most diverse in North and South America. Anarthrophytum and Sellocharis are also South American and Aryrolobium ranges into India.

Description

The Genisteae arose 32.3 ± 2.9 million years ago (in the Oligocene). The members of this tribe consistently form a monophyletic clade in molecular phylogenetic analyses. The tribe does not currently have a node-based definition, but several morphological synapomorphies have been identified:

Most (and possibly all) genera in the tribe produce 5-O-methylgenistein. Many genera also accumulate quinolizidine alkaloids, ammodendrine-type dipiperidine alkaloids, and macrocyclic pyrrolizidine alkaloids.

Broom

A broom is a cleaning tool consisting of usually stiff fibers (often made of materials such as plastic, hair, or corn husks) attached to, and roughly parallel to, a cylindrical handle, the broomstick. It is thus a variety of brush with a long handle. It is commonly used in combination with a dustpan.

In many Asian countries, however, brooms are not always made of stiff fibers, as there is often a distinction between a "hard broom" and a "soft broom". Soft brooms are made for sweeping the walls of cob webs and spiders, and are very important for that reason. Hard brooms are made for the harder job of actually sweeping dirt off sidewalks.

Etymology

The word "broom" derives from the name of certain thorny shrubs (Genista and others) used for sweeping. The name of the shrubs began to be used for the household implement in Late Middle English and gradually replaced the earlier besom during the Early Modern English period. The song Buy Broom Buzzems (by William Purvis 1752–1832) still refers to the "broom besom" as one type of besom (i.e. "a besom made from broom")

Cytisus scoparius

Cytisus scoparius, the common broom or Scotch broom, syn. Sarothamnus scoparius, is a perennial leguminous shrub native to western and central Europe. In Britain and Ireland, the standard name is broom, but this name is also used generically for other related species (see broom), and the term common broom is sometimes used for clarification. In other English-speaking countries, the most prevalent common name is Scotch broom (or Scot's broom); English broom is also occasionally used.

Classification

There are two subspecies of Cytisus scoparius:

Description

Plants of Cytisus scoparius typically grow to 1–3 m (3.3–9.8 ft) tall, rarely to 4 m (13 ft), with main stems up to 5 cm (2.0 in)thick, rarely 10 cm (3.9 in). The shrubs have green shoots with small deciduous trifoliate leaves 5–15 mm long, and in spring and summer is covered in profuse golden yellow flowers 20–30 mm from top to bottom and 15–20 mm wide. Flowering occurs after 50-80 growing degree days. In late summer, its legumes (seed pods) mature black, 2–3 cm long, 8 mm broad and 2–3 mm thick; they burst open, often with an audible crack, forcibly throwing seed from the parent plant. This is the hardiest species of broom, tolerating temperatures down to about −25 °C (−13 °F).C. scoparius contains toxic alkaloids that depress the heart and nervous system.