Digitaria horizontalis

NAME: Digitaria horizontalis

FAMILY: Poaceae (Grass family)

COMMON NAMES: Creeping crabgrass, Summer grass

LOCAL NAMES: Shama grass (India), Tokouso (West Africa)

MORPHOLOGICAL DESCRIPTION: Digitaria horizontalis, commonly known as creeping crabgrass, is a warm-season annual grass that spreads by creeping stolons. It typically grows in dense mats with wiry, thin stems that can reach up to 50 centimeters in height. The leaves are slender, linear, and arranged alternately along the stem. The inflorescence consists of numerous tiny spikelets arranged in branched, digitate clusters. The spikelets contain small, grain-like seeds.

USEFUL PART(s): The entire plant, including the leaves, stems, and seeds, can have various uses.

GENERAL USES:

  1. Forage: Digitaria horizontalis is often used as forage for livestock due to its high nutritional content. It provides a valuable source of food for grazing animals.

  2. Erosion control: The dense mat-like growth of creeping crabgrass helps stabilize soil and prevent erosion in areas with disturbed or bare soil.

  3. Lawn grass: In some regions, creeping crabgrass is cultivated as a lawn grass due to its ability to tolerate heat and drought conditions.

  4. Medicinal uses: In traditional medicine, some cultures use Digitaria horizontalis for its purported medicinal properties, such as in the treatment of digestive disorders and skin ailments.

GEOGRAPHIC DISTRIBUTION: Digitaria horizontalis is native to tropical and subtropical regions, and it has a wide distribution across different continents. It can be found in parts of Africa, Asia, the Americas, and Australia. It thrives in warm and humid environments, often growing in disturbed areas, cultivated fields, lawns, and along roadsides.

WHY IS IT GREEN? Like other plants, Digitaria horizontalis appears green due to the presence of chlorophyll in its cells. Chlorophyll is a pigment that plays a vital role in photosynthesis, the process by which plants convert sunlight into energy to fuel their growth. Chlorophyll molecules absorb light from the red and blue regions of the electromagnetic spectrum and reflect green light, giving plants their characteristic green color.

ENVIRONMENTAL IMPACT:

  1. Invasive potential: Digitaria horizontalis can sometimes become invasive, spreading rapidly and outcompeting native plant species. It can colonize disturbed areas, agricultural fields, and gardens, reducing biodiversity and affecting ecosystem dynamics.

  2. Weed pressure: Creeping crabgrass can be a problematic weed in lawns and agricultural fields, as it competes with desired plants for resources such as nutrients, water, and sunlight.

  3. Erosion control: On the positive side, Digitaria horizontalis can contribute to erosion control by stabilizing soil with its dense mat-like growth, particularly in areas prone to soil erosion.

FUN FACT:

Digitaria horizontalis is known as "crabgrass" due to its habit of growing low to the ground and spreading horizontally, resembling the creeping movement of crabs. Despite its reputation as a weed, creeping crabgrass has adapted to survive in diverse environments and has found useful applications in different cultures around the world.

FURTHER READING:

  1. "Weeds of North America" by Richard Dickinson and France Royer - This comprehensive guide provides information on various weeds, including Digitaria horizontalis, and their identification, ecology, and control.

  2. "Plant Invaders: The Threat to Natural Ecosystems" by Quentin C.B. Cronk and Janice L. Fuller - This book explores the impacts of invasive plant species on natural ecosystems, including the ecological implications of Digitaria horizontalis.

  3. "Grasses: Versatile Partners for Uncommon Garden Design" by Nancy J. Ondra and Saxon Holt - Although not specifically focused on Digitaria horizontalis, this book provides valuable insights into the world of ornamental grasses, including their selection, cultivation, and design uses.

  4. Research articles: You can search for scientific articles on Digitaria horizontalis in online databases such as Google Scholar or PubMed. Topics to explore can include its ecological impacts, physiological adaptations, genetic diversity, or ethnobotanical uses.