red rhubarb crown with stalks in early spring, with new leaves. leaves contain oxalic acid

acid angiosperms buckwheat canadian caryophyllales close contain crown crowning cultivated dormancy early edible eudicots gardening genus growing herbaceous leaf leaves macro medicinal new oxalate oxalic perennial pink plant planted poisonous polygonaceae polygonoideae red rhabarbarum rheum rhizomes rhubarb root roots spring stalks vegetable