Thursday, January 7, 2010
Sagittaria sagittifolia - Arrowhead 芽菇
Sagittaria sagittifolia ( also called arrowhead due to the shape of its leaves, ) is a flowering plant in the family Alismataceae, the water-plantain family. The Sagittaria genus consists of about 20 species worldwide. It is native to wetlands throughout the temperate regions of Europe and
The name derived from Latin word sagitta, means an arrow.
It is a herbaceous perennial plant, growing in water from 10 – 50 cm deep. It forms 3 types of leaves : submerged ( ribbon-like ), floating leaves ( transitional in shape ), and above water ( arrow-head-shaped ). The arrowhead-shaped leaves’ blade 15 – 25 cm long and 10 – 22 cm broad, on a long triangular petiole holding the leaf up to 45 cm above water level. The flowers are monoecious, 2 – 2.5 cm broad, with 3 small sepals and 3 white petals, and numerous purple stamens. Fruits are achenes.
It requires a moist or wet loamy soil in a sunny position. Due to its C3 photosynthesis pathway, it cannot grow in the shade. It prefers shallow, still or slowly flowing water up to 30 – 60 cm deep. The plants are fairly cold tolerant, surviving temperatures down to at least -10°c, though the top growth is damaged once temperatures fall below zero. Average yield maybe 12 – 15 t/ha. Reproduction by floating seeds or vegetatively.
Sagittaria is a general nuisance in the crops’ irrigation systems, drains and waterways of more than 50 countries.
The tuber is edible. It is know as cígū (慈菇, literally mean "benevolent mushroom") or yagū ( 芽菇 ).