Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Tribe: Trifolieae
Genus: Melilotus
Species: M. albus
Binomial name: Melilotus albus
Synonyms: Melilotus officinalis subsp. albus, Melilotus leucanthus, Melilotus albus var. annuus, Melilotus alba, Melilotus alba, Melilotus albus
Common names: White sweet clover, Bokhara clover, honey clover, tree clover, sweet clover, white melilot

Melilotus albus is a cosmopolite and invasive legume species, native to Europe and Asia. In New Zealand, it has become invasive and can out-compete native plant species. It can grow up to 2 meters in height and can produce abundant amounts of seeds that readily float and disperse in water. This has allowed the plant to colonise natural habitats such as riparian areas, agricultural areas, natural forests, grasslands and disturbed areas. In New Zealand, it is common in the Hawkes Bay and inWellington. It is also found in a few areas in the north and east of the South Island.

Melilotus alba is a biennial herb with pea-like flowers attached to small stalks of elongated stems (Cole, 1990). It is monocarpic, sweet-scented, and has trifoliate leaves (Ekhardt, 1987). The leaves are alternate in arrangement and are 12.7-50.8mm (.5-2 in) (ANHP, 2006). The flowers are perfect spike-like racemes (Ekhardt, undated). The flowers are about 3-6.3mm (ANHP, 2006). The seed is ovoid, leathery, and wrinkled. M. alba is somewhat dehiscent. The plant is erect, branched and has a glabrous stem. M. alba is 1-3m high. The corolla is 4-5mm long and the fruit is 3-4mm and reticulate. Melilotus alba flowers during summer. Flowering shoots can reach up to 1m. According to Frame (undated), the "seed pod has a reticulated, ridged coat which turns black with ripening and contains a single smooth kidney-shaped seed, about 2mm long, and brownish-yellow to brown."
Melilotus alba has high self-fertility and cross fertility rates. It is pollinated by bees and wasps. Rainwater and runoff are the most important means of seed dispersal and the wind can carry the seeds several metres. 1987).

White sweet clover Melilotus albus-007.JPG

White sweet clover Melilotus albus-005 2 .JPG

White sweet clover Melilotus albus-005.JPG

White sweet clover Melilotus albus-006.JPG

The trifoliate leaves.
White sweet clover Melilotus albus-001.JPG


Thanks to Global Invasive Database http://issg.org/

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/