Genista
Sp. Pl. 2: 709. 1753.
Shrubs [small trees], armed or unarmed, 1–6 m. Stems erect, branched from base, slender, striate, persistently greenish, sericeous to glabrescent. Leaves often caducous, alternate or opposite, unifoliolate or odd-pinnate; stipules present [absent], inconspicuous, adnate to leaf bases; sessile or petiolate; leaflets 1 or 3, blade margins entire, surfaces glabrous or pubescent. Inflorescences 1–20[–30]-flowered, terminal or axillary, clusters or racemes [panicles], or flowers solitary; bracts present. Flowers papilionaceous; calyx tubular-campanulate, bilabiate, abaxial lip 3-lobed, adaxial lip 2-lobed; corolla yellow, petals clawed; stamens 10, monadelphous; anthers basifixed, dimorphic; ovary sessile, style abruptly incurved distally, glabrous. Fruits legumes, stipitate, compressed, narrowly oblong [falcate-rhomboid and inflated], dehiscent, not constricted between seeds, usually pubescent, rarely glabrous. Seeds 3–10, ovoid, cordate, ellipsoid, rhombic, or orbicular, strophiolate. x = 24.
Distribution
Introduced; w Europe, n Africa, introduced widely.
Discussion
Species ca. 90 (5 in the flora).
A. Kleist et al. (2014) found evidence suggesting multiple horticultural introductions of Genista monspessulana (French broom) in California. They also indicated that inter-taxon hybridization may also be occurring among the Genista populations in the state, possibly contributing to the invasive success of the species.
A small population of Genista pilosa Linnaeus was recently found on Vancouver Island, British Columbia (F. Lomer 7732, UBC V236493, Sep. 7, 2011).
Selected References
None.
Lower Taxa
Key
| 1 | Leaflets 1. | Genista tinctoria |
| 1 | Leaflets 3. | > 2 |
| 2 | Leaflet blades linear to narrowly elliptic, margins revolute. | Genista linifolia |
| 2 | Leaflet blades elliptic to oblanceolate, obovate, or elliptic, margins entire, sometimes ciliolate. | > 3 |
| 3 | Leaflet blades 5–10 mm; banners with V-shaped patch of pubescence from base to apex; wings and keel longer than banner. | Genista canariensis |
| 3 | Leaflet blades (5–)10–25 mm; banners glabrous; wings and keel slightly shorter than banner. | > 4 |
| 4 | Inflorescences terminal racemes; bracts 1–2.5 mm; seeds orbicular, 2.5–3 mm, olive to brownish or black, hilum red-orange. | Genista maderensis |
| 4 | Inflorescences dense, axillary clusters on short shoots; bracts 2–3 mm; seeds ovoid, 1–1.3 mm, tan to dark brown, hilum greenish yellow. | Genista monspessulana |