Low, creeping perennial. Fields, roadsides, lawns, everywhere. America, Europe, Asia. April-November.
Creeping and spreading by runners, rooting at the nodes or joints.
On long petioles, compound, of three leaflets; occasionally a leaf is found bearing four or more. A four-leaf clover is always accepted as a token of good luck. Leaflets rounded oval, obovate or obcordate; margins obscurely toothed, and surfaces usually marked with a grayish green triangular band, the angle of which points to the apex.
In heads, cream-white, frequently pinkish.
Small, five-parted, pale green.
Five papilionaceous petals united into a tube; as they fade they become brown, turn downward, separating the head into two parts, the active and the faded, until finally all are reflexed and the seeds ripen.
Ten, diadelphous, that is, in two brotherhoods; one with nine filaments united, one with filament separate from the others.
A four-seeded pod.
Pollinated by honey-bees. Nectar-bearing.
The White Clover is the low Clover that creeps over the lawns, that comes up in the flower-beds, that makes close, thick patches by the roadsides, and in climates too warm for grass is often used as a dooryard cover. It was long believed to be an immigrant from Europe but is now considered one of the few species whose habitat is worldwide, a native of Europe, Asia, and America.
The plant is a low, creeping perennial that makes its way by runners that root along the surface of the ground. This rooting stem sends up leaves upon long petioles, and also slender flower-stems, each of which bears one flower-head of white florets. These florets are fragrant, full of nectar which can be reached by the honey-bee, and White Clover honey is one of the choicest brands in the market.
The heads are never pretty because the lower florets open first and are successively reflexed, so that during the flowering period the heads appear horizontally divided between the withering and the opening florets.
The leaf of the White Clover may well challenge attention because of the interesting and independent way that the leaflets behave when night comes on. To observe this sleep movement select any White Clover leaf having an upright petiole and with the three leaflets expanded horizontally. As the evening comes on the two side leaflets will be seen to twist and approach each other until their upper surfaces come into contact. At the same time they bend downward. The terminal leaflet merely rises up without any twisting and bends over until it rests on and forms a roof over the edges of the two united lateral leaflets. When this movement is complete the terminal leaflet stands at night horizontally with its lower surface fully exposed. Leaves vary somewhat, but this is the typical arrangement.
White Clover Leaves at Night. Trifolium ripens
Charles Darwin, writing upon this subject, says: "The fact that the leaves of many plants place themselves at night in widely different positions from what they hold during the day, but with the one point in common that their upper surfaces avoid facing the zenith, often with the additional fact that they come into close contact with opposite leaves or leaflets, clearly indicates, as it seems to me, that the object gained is the protection of the upper surfaces from being chilled at night by radiation. There is nothing improbable in the upper surface needing protection more than the lower, as they differ in structure."
The flowers of all the Clovers are papilionaceous, but, crowded as they are in heads, the petals have grown together and become tubular.
The generic name Trifolium alludes to the three-parted compound leaf which is characteristic of the genus. The name Clover is thought to have been derived from the Latin clava, meaning club in connection with the mythical three-headed club of Hercules which the Clover leaf is supposed to resemble. The clubs on playing-cards are believed to have originated from the Clover leaf. Among the common names of this plant in England are Sheep's Gowan, Honey-stalks, and Shamrock.
Belief in the magical and mystical power of certain leaves and plants is very wide-spread and appears in proverbs and jingles, of which the following is an example:
"Find even Ash or four-leaved Clover You will see your true love Before the day is over."