Water caltrop is the rhizome of the plant water caltrop, which belongs to the family Hydrocharitaceae. It has the effects of clearing heat, promoting diuresis, invigorating blood circulation, and promoting meridian circulation. It is used for cloudy urine, diarrhea, dysentery, rheumatism, and injuries from falls or blows.
【Morphological Characteristics of Water Caltrop】
Water caltrop is also known as Marsilea quadrifolia, sword grass, Anqing, and Japanese water fern.
The plant is 10-40cm tall with long and horizontally growing rhizomes that are forked. The rhizomes are usually bare and covered with white powder, with oval-lanceolate scales at the top that gradually taper. The scales have fine serrations on the edges and are shield-shaped.
The leaves are distantly spaced; the petioles are 5-20cm long and jointed on the rhizomes; the leaf blades are thin and papery, oblong-lanceolate in shape, 8-20cm long and 4-8cm wide, gradually narrowing towards the top;
They often have short tail heads and are densely covered with gray-white short soft hairs on both sides. The leaves are deeply lobed and reach the leaf axis. The lobes have entire margins and blunt or short pointed heads, with a pair of lobes sloping downward at the base. The veins form a reticulate pattern, with one row of reticulations on each side of the midvein.
The sporangia are round and located at the tip of the internal hidden veins, forming one row on each side of the midvein. There is no sporangial cover.
【Medicinal Applications of Water Caltrop】
Treats urticaria: Take 2 to 4 liang of fresh water caltrop rhizomes and ten red dates, decoct in water and take orally. Also, take one jin of the whole plant, decoct in water and use for bathing while it is still hot.
Treats infantile high fever with convulsions: Take one or two liang of fresh water caltrop, and five qian of a yellow flower herb. Decoct in water and take orally.
Treats urinary tract infections: Take two liang of water caltrop and one liang of yam root. Decoct in water and take orally.
Treats toothache: Take three qian of fresh water caltrop, five qian of honeysuckle, and three qian of Chinese ivy. Decoct in water and take orally.
Treats acute arthritis: Take four liang of water caltrop rhizomes and a small amount of rock sugar. Decoct in water and take orally.
