The common name “Star Grass” refers to two distinct botanical groups: highly productive tropical and subtropical grasses, and a group of small, star-flowered perennial herbs. These groups are utilized for fundamentally different purposes, ranging from large-scale commercial forage production and turf management to traditional medicine. Understanding the specific identity of the plant is necessary to recognize its role in agriculture, landscaping, or health practices.
Clarifying the Identity of “Star Grass”
Plants known as Star Grass fall into two main botanical groups. One group consists of species from the genus Cynodon, which are true grasses closely related to Bermuda grass. These robust, perennial plants spread aggressively using thick, above-ground runners called stolons and sometimes underground stems called rhizomes. The stems (culms) of these forage types can grow between 30 and 100 centimeters high, forming dense, expansive mats.
The second major group belongs to the genus Hypoxis, which are not true grasses despite their common name. These low-growing herbaceous perennials are easily identified by their small, bright yellow, star-shaped flowers that typically feature six tepals. They develop from a bulb-like underground storage organ called a corm or rhizome. The leaves are narrow, strap-like, and grow from the base of the plant, often bearing scattered white hairs.
Star Grass in Agriculture and Turf Management
The agricultural and turf applications of Star Grass focus on Cynodon species, such as African Star Grass, which thrive in tropical and subtropical climates. These warm-season grasses are prized for their vigorous growth and high yield, making them a primary forage crop for grazing livestock and hay production. Certain varieties can produce significant dry matter yields, sometimes reaching 2 to 2.5 tons per acre within 60 days of planting.
The grass is propagated vegetatively using stolons or sprigs, allowing for rapid establishment of a dense stand. It is drought-tolerant and recovers quickly from heavy grazing or cutting. This dense, fast-growing habit is beneficial in turf management for creating durable sports fields and pastures. Maintaining quality forage requires a rotational system, typically allowing a rest period of four to five weeks between grazing or cutting to maximize yield.
Ethnobotany and Traditional Medicinal Applications
Traditional medicinal interest focuses almost entirely on the Hypoxis varieties, particularly Hypoxis hemerocallidea, often called African potato. Extracts from the corms and rhizomes are used in African traditional medicine to treat a variety of ailments. Traditional preparations address conditions such as inflammation, urinary infections, and immune support.
Scientific study has identified several unique phytochemicals responsible for their efficacy. The most significant compound is hypoxoside, a norlignan diglucoside, concentrated in the underground storage organs. When ingested, hypoxoside is metabolized into rooperol, which has drawn attention for its potential anti-neoplastic properties. Additionally, the corms are a source of phytosterols, such as beta-sitosterol, marketed for their supportive role in immune function and in addressing benign prostate hypertrophy.
Ecological Spread and Management
The robust growth habit of Cynodon species contributes to their ecological spread and potential invasiveness. These types are highly competitive, spreading rapidly via woody stolons, allowing them to outcompete other grasses and weeds. This aggressive propagation and tolerance for a wide range of soil types have made many Cynodon species widespread throughout tropical and subtropical regions.
Intentional cultivation leverages this spreading nature for ground cover and erosion control. However, once established, the dense network of vegetative runners makes eradication difficult, often requiring persistent manual removal of the rhizomes and stolons. Proper management, such as maintaining a recommended stubble height during grazing, is required to ensure the cultivated stand remains persistent.