golden clover

not listed

NNA - Not applicable

SNA - Not applicable

not listed

Golden clover is native to Europe and Asia. It was introduced into North America in the eighteenth century and cultivated. According to one source*, George Washington ordered seeds of this species from Europe in 1786. It eventually escaped cultivation and it is now naturalized. It occurs in the United States in the east from Maine to Minnesota south to North Carolina and Missouri, in the west from Washington to Montana, and in adjacent Canadian provinces. In Minnesota it is common in the northeast and north-central regions, scattered in the metro and southeast, and mostly absent elsewhere.

Golden clover is an 8″ to 20″ tall, annual or biennial forb that rises on one to several stems from a taproot. It often forms colonies. The stems are erect or ascending, often much branched, and covered with short appressed hairs. They do not root at the nodes.

The leaves are alternate though they may sometimes appear opposite on flowering branches. They are on leaf stalks (petioles) that can be 3 ⁄16″ to ½″ (5 to 12 mm) long but are always shorter than the leaflets. The petioles get gradually shorter as they ascend the stem. At the base of each petiole there is a pair of conspicuous, persistent, leaf-like appendages (stipules) that are about as long or slightly longer than the petiole. The stipules are oblong lance-shaped, prominently veined, and fused at the base to the petiole for about half their length. The free half of each stipule is narrow and long tapered to the tip.

The leaves are divided into 3 leaflets, all of them stalkless. The leaflets are papery thin, ⅜″ to ⅞″ (10 to 23 mm) long, and 3 ⁄16″ to 5 ⁄16″ (5 to 8 mm) wide. The leaflet blades may be inversely egg-shaped, inversely lance-shaped, or elliptical. They are tapered to the base and rounded or broadly and bluntly pointed at the tip. They are sometimes shallowly notched at the tip, and there is sometimes a short, sharp, abrupt point at the tip. There is a prominent midvein and 10 to 18 pairs of lateral veins. The upper and lower surfaces are usually hairless. The margins are untoothed below the midpoint, finely toothed above the midpoint.

The inflorescence is single, dense, globe-shaped or short cylinder-shaped clusters of 25 to 40 overlapping flowers rising from upper leaf axils. Each cluster is ⅜″ to ¾″ (10 to 20 mm) long, ½″ to 9 ⁄16″ (12 to 14 mm) wide, and at the end of a hairy ⅜″ to 2″ (10 to 15 mm) long stalk (peduncle). The peduncle is as long or longer than the cluster. Individual flowers are erect when in bud, spreading when in bloom, and drooping when in fruit.

Each flower is 3 ⁄16″ to ¼″ (5 to 7 mm) long and on a very short stalk (pedicel). There are 5 sepals, 5 petals, and 10 stamens. The group of sepals (calyx) is light green, small, and inconspicuous. It is fused at the base into a 1 ⁄32″ (0.8 to 1.0 mm) long tube then separated into 5 teeth. The lower teeth are the longest, 2 to 3 times longer than the upper teeth, and 2 or 3 times longer than the calyx tube. The petals are bright yellow and are organized like a typical pea flower, with an upper banner, a pair of lateral wing petals, and a pair of lower keel petals. The banner is broadly inversely egg-shaped and slightly curved inward. It has a broad, shallow notch at the tip. The outer surface is conspicuously veined. The wing petals are dilated and concave. The keel petals are fused along the lower margin and appear as a single folded unit enclosing the stamens and pistil. The petals become brown and papery with age. The stamens have long stalks (filaments) and small anthers. The filaments of nine of the stamens are fused together for most of their length. The tenth stamen is free.

The fruit is a narrowly egg-shaped, ⅛″ (2.5 to 3.0 mm) long seed pod containing a single seed.

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* Yatskievych, George, and Steyermark. 2013. Steyermark’s Flora of Missouri Volume 3; page 149. Jefferson City, Missouri: The Missouri Department of Conservation.

8″ to 20″

Yellow

Old fields, roadsides, open disturbed sites

May to September

Sources

2, 3, 4, 5, 7, 22, 28, 29, 30.

Native to Europe and Asia. Introduced and naturalized in North America.

Common

Several of the Trifolium species that occur in Minnesota have had two or more subspecies and/or varieties described. For all of these species, the infrataxa are recognized by GRIN but not by ITIS or USDA PLANTS.

Two subspecies have been described. Only the nominate subspecies, ssp.aureum, occurs in North America.

The common name hop clover refers to the appearance of the flower heads. After maturity they turn brown and hang downward, resembling hops.

Plants

Inflorescence

Flower Head

Flowers

Leaves