pointedleaf ticktrefoil

Desmodium glutinosum

Description:

Pointedleaf ticktrefoil (Desmodium glutinosum) is a herbaceous perennial plant native to North America. Below is a breakdown of its morphology and ecology:

Morphology (Physical Characteristics)

1. Leaves:
   • Compound with three leaflets (trifoliate).
   • The leaflets are ovate to lance-shaped with pointed tips, giving the plant its common name.
   • Upper leaf surface is usually smooth or slightly rough, while the underside can be more hairy.
2. Height:
   • Grows between 1 to 3 feet (30–90 cm) tall.
3. Flowers:
   • Small, pea-like flowers in light pink to purple shades.
   • Blooms in mid to late summer (July through September).
   • Flowers are arranged in racemes along the upper part of the stem.
4. Fruit:
   • Produces flat, segmented pods (loments) that break apart easily.
   • Each segment contains a single seed and is covered in tiny hooked hairs, helping it attach to animals (a mechanism known as epizoochory).
5. Stems:
   • The stems are sticky or covered with glandular hairs, giving the plant a “glutinous” feel (which aligns with its species name, glutinosum).

Ecology (Habitat and Role in Ecosystem)

1. Habitat:
   • Found primarily in woodlands, forests, and shady clearings, especially in rich, moist soils.
   • Thrives in both deciduous forests and along forest edges, preferring partial to full shade.
2. Distribution:
   • Native to the eastern and central United States and parts of southeastern Canada.
3. Pollination:
   • Pollinated by a variety of insects, particularly bees that are attracted to the nectar and flowers.
4. Seed Dispersal:
   • The plant uses epizoochory (dispersal by attaching to animal fur or human clothing) to spread its seeds.
5. Ecological Role:
   • Nitrogen fixation: Like other legumes, pointedleaf ticktrefoil forms symbiotic relationships with nitrogen-fixing bacteria, improving soil fertility.
   • Wildlife support: Provides food and habitat for bees and other insects. The seeds are consumed by some small mammals and birds.
6. Adaptations:
   • Sticky pods aid in seed dispersal, increasing the plant’s reach.
   • Tolerance for low-light conditions allows it to thrive under forest canopies where competition for light is high.

This plant plays a key role in forest ecosystems by contributing to soil health and supporting insect populations.

Details:

pointedleaf ticktrefoil

References:

1. Integrated Taxonomic Information System – Amphicarpaea bracteata
2. USDA Plants Database – Amphicarpaea bracteata
3. WisFlora Database – Amphicarpaea bracteata