Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Core eudicots
Order: Caryophyllales
Family: Amaranthaceae
Subfamily: Betoideae
Genus: Beta
Species: B. vulgaris
Binomial name: Beta vulgaris
Common names: Beet, Weed beet.

Beta vulgaris is a herbaceous biennial or, rarely, perennial plant with origins in Coastal Europe, N. Africa, W. Asia. Now naturalised in New Zealand.
It has leafy stems and grows to 1–2 m tall. The green leaves are heart-shaped, 5–20 cm long on wild plants (often much larger in cultivated plants).
The flowers are produced in dense spikes; each flower is very small, 3–5 mm diameter, green or tinged reddish, with five petals; they are wind pollinated. The fruit is a cluster of hard nutlets.
It has numerous cultivated varieties, the most well known of which is the root vegetable known as the beetroot or garden beet.

Photographed on the harbour edge, Pauatahanui inlet, Mana, Wellington. Washed up seaweed top right.
Beta vulgaris Beet .JPG

Beta vulgaris Beet -002.JPG

The leaf.
Beta vulgaris Beet -001.JPG 

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