| Noun | 1. | sour grass - any of certain coarse weedy plants with long taproots, sometimes used as table greens or in folk medicineherb, herbaceous plant - a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests genus Rumex, Rumex - docks: coarse herbs and shrubs mainly native to north temperate regions Rumex acetosa, sour dock, garden sorrel - European sorrel with large slightly acidic sagittate leaves grown throughout north temperate zone for salad and spring greens Rumex acetosella, sheep sorrel, sheep's sorrel - small plant having pleasantly acid-tasting arrow-shaped leaves; common in dry places bitter dock, broad-leaved dock, Rumex obtusifolius, yellow dock - European dock with broad obtuse leaves and bitter rootstock common as a weed in North America French sorrel, garden sorrel, Rumex scutatus - low perennial with small silvery-green ovate to hastate leaves |