Polygonum cuspidatum P.E.

Latin name: Polygonum cuspidatum
Chinese name: Hu Zhang
Family: Polygonaceae
Genus: Polygonum
Plant original: Polygonum cuspidatum Sieb.
Part used: Rhizome
Specification: Resveratrol 1%--98% Test By HPLC
1  The summary
The protophyte of Polygonum is regarded as rhizome and root of Polygonum cuspidatum Sieb. et Zucc., perennial herbaceous, being one of the Chinese medicinal herbs most in use in ancient China. 
Shape:  Perennial herbaceous, with height 1—1.5m.  Rhizome lays across underground, in yellow color.  Stem is coarse & strong, straight, with no hairs on the surface, and small flower in pale or light pale-green color. 
Cultivation:  Fond of warm weather in nature, Polygonum better grows in moist & loose soil.  Choose the arenaceous soil rich of humus when cultivating.  It’s also suitable to be cultivated by the ditch, in woodland of the hillside, and in front of or behind the house.  Before soil preparation, apply tens of Kg of organic fertilizer per Mu.  Plough the fields deep to 20—30cm.  Prepare the earth as bed after ploughing.  Planting method:  1.  Seed breeding:  Dig a pit with space 33x33cm between in the middle of April, in which sow 8—9 pieces of seed.  Cover soil with 3cm thick, then watering later.  2.  Breeding by root:  Before sprouting in early spring, excavate the mother plant, cut the rhizome to small pieces about 15—20cm long, dig the ditches upto 7—10cm deep according to a row space of 66cm.  Put 2 pieces of rhizome in horizontal direction every 45cm of space, cover the soil and press tightly.  No need to water for the moisture soil.  Thin out seedling at  7—10cm of length.  Leave 1—2 strong plants in every ditch, intertill and remove weeds in time during growth period.  Do topdressing 3 times a year, with nitrogenous fertilizer in spring and phosphate & potash fertilizer in summer, along with keeping the fields moisture.  Pay attention to preventing from aphid, epicauta arorha and scarab.
Harvest:  Administration by root and rhizome, Polygonum can be digged both in spring and autumn.  Root-like stem and stem, leaf are better to be gathered during spring and summer.  And the root is better to be gathered in spring and autumn. Cut it to pieces while fresh after cleaning and then leave to dry in the sunshine.  Those with strong root and non-withered inside are considerably as good ones.  Remove the fibrous root and the tail, cut to pieces after cleaning, leave to dry in the sunshine, keep in dry places.  Be cautious of mould-proof & worm-eaten.  Prepared small pieces should be stored in wooden case and jar.
Distribution:  Polygonum most grows in ravine, by the river and in shady-warm places under trees, mainly distributed in the south of Changjiang River, Shan’xi, Henan and Shandong provinces in China.