# Hop Trefoil (*trifolium campestre*) Hop Trefoil is a charming annual herbaceous plant belonging to the legume family, Fabaceae. It is widely recognized for its cheerful, bright yellow flower heads that closely resemble miniature hops, which gives the plant its distinctive common name. Native to Europe and Western Asia, this resilient clover has successfully naturalized in many other regions worldwide, including North America and Australia. It plays a valuable ecological role by forming symbiotic relationships with soil bacteria to fix nitrogen, enriching the surrounding soil while providing nutrient-rich forage for livestock and a vital source of nectar for local pollinators. - **Category:** [Plants](https://www.snappit.app/explore/categories/plant) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Snaps:** 2 - **Habitat:** Typically found in open, sunny environments such as dry pastures, grassy fields, roadsides, waste areas, and coastal dunes. ![Hop Trefoil](https://inaturalist-open-data.s3.amazonaws.com/photos/73248929/medium.jpg) Photo: Kevin Thiele, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/73248929) ## Appearance This low-growing plant typically reaches heights of 10 to 30 cm, featuring slender, reddish-brown, hairy stems that can be upright or trailing. Its leaves are alternate and trifoliate, with three small, oblong leaflets; crucially, the central leaflet has a distinct short stalk, separating it from the side leaflets. The tiny, bright yellow flowers are clustered in spherical or egg-shaped heads about 8 to 15 mm wide. As they mature, the flowers turn light brown, dry up, and droop downwards, taking on a papery appearance resembling hops. ## Taxonomy - **Kingdom:** Plantae - **Phylum:** Tracheophyta - **Class:** Magnoliopsida - **Order:** Fabales - **Family:** Fabaceae - **Genus:** Trifolium ## Interesting facts - The dried flower heads closely resemble real hops used in beer brewing, which is how it earned its common name 'Hop Trefoil'. - The species name 'campestre' is Latin for 'of the fields', pointing directly to its favorite grassy and meadow habitats. - Unlike many other common clovers where all three leaflets branch from the exact same point, Hop Trefoil's central leaflet has its own distinct petiolule (leaf stem). ## Special abilities - **Nitrogen-Fixing Nodules:** Formulates a symbiotic partnership with rhizobia bacteria in its roots, allowing it to convert atmospheric nitrogen into a usable organic form, which enriches the soil. - **Seed Longevity:** Produces hardy seeds with a tough outer coat that can remain dormant and viable within the soil seed bank for several years until growing conditions are optimal. - **Nyctinastic Sleep:** Folds its leaflets together downwards at night to reduce water loss through transpiration and protect delicate surfaces from overnight chill. ## Measurements & details - **Length:** 10-30 cm - **Lifespan:** 1 years ## Diet & Feeding As an autotrophic plant, Hop Trefoil produces its own food through photosynthesis using sunlight, carbon dioxide, water, and essential mineral nutrients absorbed from the soil. - **Primary Foods:** Sunlight, Carbon dioxide, Water, Soil nitrogen, Phosphorus ## Ecological connections - **Mutualism:** Western Honey Bee (*Apis mellifera*) — Provides nectar and pollen to pollinating insects in exchange for pollination. - **Host plant:** [Clouded Sulphur](https://www.snappit.app/explore/clouded-sulphur) (*Colias philodice*) — Serves as a larval host plant where caterpillars feed on the leaves. - **Competitor:** [White Clover](https://www.snappit.app/explore/white-clover) (*Trifolium repens*) — Competes for soil space, light, and nutrients in pastures. ## Safety **Danger:** 1/5 · Very low No special safety notes yet. ## Frequently Asked Questions ### How to identify Hop Trefoil? Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details. ### How long is Hop Trefoil? 10-30 cm ### How long does Hop Trefoil live? 1 years ### What does Hop Trefoil eat? As an autotrophic plant, Hop Trefoil produces its own food through photosynthesis using sunlight, carbon dioxide, water, and essential mineral nutrients absorbed from the soil. ### Where is Hop Trefoil usually found? Typically found in open, sunny environments such as dry pastures, grassy fields, roadsides, waste areas, and coastal dunes. ## Where to spot - [Americus Historic District](https://www.snappit.app/guides/places/americus-historic-district) — Georgia, US · Historic District - [Cedarmere-Clayton Estates](https://www.snappit.app/guides/places/cedarmere-clayton-estates) — New York, US · Historic District - [Fletcherville Historic District](https://www.snappit.app/guides/places/fletcherville-historic-district) — Georgia, US · Historic District - [Mobile Botanical Gardens](https://www.snappit.app/guides/places/mobile-botanical-gardens) — Alabama, US · Botanical Garden - [Thomasville Commercial Historic District](https://www.snappit.app/guides/places/thomasville-commercial-historic-district) — Georgia, US · Historic District [View all places to see Hop Trefoil](https://www.snappit.app/guides/where-to-see/hop-trefoil) ## More Plants - [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*) - [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*) - [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*) - [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*) --- Source: [Hop Trefoil: Facts & Places to See — Snappit](https://www.snappit.app/explore/hop-trefoil)