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, 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 Argyrolobium ranges into India.

Description

The Genisteae arose 32.3 ± 2.9 million years ago. 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:
… bilabiate calyces with a bifid upper lip and a trifid lower lip, … the lack of an aril, or the presence of an aril but on the short side of the seed, and stamen filaments fused in a closed tube with markedly dimorphic anthers … and presence of α-pyridone alkaloids.

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

Name

bróm is from a common West Germanic *bráma-, from a Germanic stem bræ̂m- from Proto-Indo-European *bhrem- "to project; a point", with an original sense of "thorny shrub" or similar. Use of the branches of these plants for sweeping gave rise to the term broom for sweeping tools in the 15th century, gradually replacing Old English besema.

Cultivation

Brooms tolerate poor soils and growing conditions. In cultivation they need little care, though they need good drainage and perform poorly on wet soils.
They are widely used as ornamental landscape plants and also for wasteland reclamation and sand dune stabilising.
Tagasaste, a Canary Islands native, is widely grown as sheep fodder.
Species of broom popular in horticulture are purple broom, Atlas broom , dwarf broom, Provence broom and Spanish broom.
Many of the most popular brooms in gardens are hybrids, notably Kew broom and Warminster broom.

Invasive species

On the east and west coasts of North America, common broom was introduced as an ornamental plant. It is known in much of the pacific northwest as Scotch broom. It has become a naturalised invasive weed, and due to its aggressive seed dispersal broom removal has proved very difficult. Similarly, it is a major problem species in the cooler and wetter areas of southern Australia and New Zealand. Biological control for broom in New Zealand has been investigated since the mid-1980s. On the west coast of the United States, French broom, Mediterranean broom and Spanish broom are also considered noxious invasives, as broom quickly crowds out native vegetation, and grow most prolifically in the least accessible areas.
, Sicily

Historical uses

The Plantagenet kings used common broom as an emblem and took their name from it. It was originally the emblem of Geoffrey of Anjou, father of Henry II of England. Wild broom is still common in dry habitats around Anjou, France.
Charles V and his son Charles VI of France used the pod of the broom plant as an emblem for livery collars and badges.
Genista tinctoria, provides a useful yellow dye and was grown commercially for this purpose in parts of Britain into the early 19th century. Woollen cloth, mordanted with alum, was dyed yellow with dyer's greenweed, then dipped into a vat of blue dye to produce the once-famous "Kendal Green". Kendal green is a local common name for the plant.
The flower buds and flowers of Cytisus scoparius have been used as a salad ingredient, raw or pickled, and were a popular ingredient for salmagundi or "grand sallet" during the 17th and 18th century. There are now concerns about the toxicity of broom, with potential effects on the heart and problems during pregnancy.