Stems: ascending, somewhat hairy; pistules broadly lanceolate, membranaceous, nerved, setaceously acuminate. Leaves: leaflets obcordate, nearly entire. Flowers: heads ovate, dense, nearly sessile, bracteate; teeth of the calyx setaceous, hairy, the lower one much longer than the other four; petals purple-red, all united into a tube at the base. Not indigenous.
Thoreau speaks of the fields blushing with Red Clover "as the western sky at evening." Every one knows the Clover. Every one has walked ankle-deep in meadows rich with its red flowers. Some of us are even fortunate enough to "live in clover," - but not all! It is a quaint conceit of the Red Clover to fold its leaves in sleep each night, the two side leaflets drooping downwards together and the terminal one bowed over them.
The name Clover probably comes from the Latin clava, meaning "club," and refers to the possible resemblance between the trefoil leaf and the three-headed club of Hercules. The "clubs" on playing cards are, no doubt, also an imitation of the clover leaf.
The Clover is believed by many people to be the ancient "shamrag"of Ireland, though others - with perhaps equal authority - claim that the National Flower of the Emerald Isle, chosen by St. Patrick to illustrate the doctrine of the Trinity, was originally the Wood-sorrel (Oxalis Acetosella) whose quaint name of Allelujah refers to the religious significance of its triple leaf. This is an introduced plant.