Belongs within: Genistinae.
Cytisus, brooms, is a western Palaearctic genus of shrubs with persistently green stems.
Characters (Hickman 1993): Shrub or small tree, unarmed, stems often ribbed, persistently green. Leaves 1-compound (generally ternate), generally alternate, petioled, stipules free or absent. Inflorescences generally racemes, terminal or flowers 1–3 in axillary, peduncled clusters. Flower with calyx bell-shaped, two-lipped, upper lip barely two-lobed, lower lip minutely three-lobed; petals white or generally yellow, banner yellow, generally not hairy, keel oblong-sickle-shaped to more or less half-circular, curved on lower surface, claw more or less 1/4 keel; stamens 10, filaments fused; style generally abruptly curved at more or less middle or gently curved entire length. Fruit dehiscent, generally oblong, papery to more or less leathery; pedicel short. Seeds few to many, generally arilled.
<==Cytisus
| i. s.: C. albusC06
| C. alpinusC55
| C. candicansC06
| C. ingramiiR-RR-GM-S98
| C. laburnumRS99
| C. purgansC74
| C. sessilifoliusT10
| C. supinus Linnaeus 1753P07
| C. villosusR-CT01
|--C. sect. AlburnoidesCTP01
| |--C. multiflorusCTP01
| |--C. oromediterraneusCTP01
| `--C. valdesiiCTP01
`--C. sect. SpartopsisCTP01
|--C. arboreusCTP01
| |--C. a. ssp. arboreusCTP01
| |--C. a. ssp. baeticusCTP01
| `--C. a. ssp. catalaunicusCTP01
|--C. grandiflorusCTP01
| |--C. g. ssp. grandiflorusCTP01
| |--C. g. ssp. barbarusCTP01
| |--C. g. ssp. cabezudoiCTP01
| `--C. g. ssp. haplophyllusCTP01
|--C. maurusCTP01
|--C. megalanthusCTP01
|--C. scopariusCTP01
| |--C. s. ssp. scopariusCTP01
| `--C. s. ssp. reverchoniiCTP01
`--C. striatusCTP01
|--C. s. ssp. striatusCTP01
`--C. s. ssp. eriocarpus [=Sarothamnus eriocarpus]CTP01
*Type species of generic name indicated
References
[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 1. Librairie de Victor Masson: Paris.
[C06] Cheeseman, T. F. 1906. Manual of the New Zealand Flora. John Mackay, Government Printer: Wellington.
[C74] Coineau, Y. 1974. Éléments pour une monographie morphologique, écologique et biologique des Caeculidae (Acariens). Mémoires du Muséum National d’Histoire Naturelle, nouvelle série, Série A, Zoologie 81: 1–299, 24 pls.
[CTP01] Cubas, P., H. Tahiri & C. Pardo. 2001. Karyological and taxonomic notes on Cytisus Desf. sect. Spartopsis Dumort. and sect. Alburnoides DC. (Genisteae, Leguminosae) from the Iberian Peninsula and Morocco. Botanical Journal of the Linnean Society 135 (1): 43–50.
Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).
[P07] Pifkó, D. 2007. Taxonomic revision and typification of Genista (Leguminosae) in the Herbarium Carpato-Pannonicum in Budapest. Annales Historico-Naturales Musei Nationalis Hungarici 99: 23–38.
[R-CT01] Ragusa-di Chiara, S., & H. Tsolakis. 2001. Phytoseiid faunas of natural and agricultural ecosystems in Sicily. In: Halliday, R. B., D. E. Walter, H. C. Proctor, R. A. Norton & M. J. Colloff (eds) Acarology: Proceedings of the 10th International Congress pp. 522–529. CSIRO Publishing: Melbourne.
[R-RR-GM-S98] Ramil-Rego, P., M. Rodríguez-Guitián & C. Muñoz-Sobrino. 1998. Sclerophyllous vegetation dynamics in the north of the Iberian peninsula during the last 16,000 years. Global Ecology and Biogeography Letters 7: 335–351.
[RS99] Rossman, A. Y., G. J. Samuels, C. T. Rogerson & R. Lowen. 1999. Genera of Bionectriaceae, Hypocreaceae and Nectriaceae (Hypocreales, Ascomycetes). Studies in Mycology 42: 1–248.
[T10] Thouin, A. 1810. Description de l’École d’Agriculture Pratique du Muséum d’Histoire Naturelle. Sixième mémoire. Classe IIIe. Genre IIIe et dernier. Des exemples de toutes les sortes de greffes exposées dans cette ecole. Observations générales. Annales du Muséum d’Histoire Naturelle 16: 209–239.