Distribution

Native to Central and South America and the Caribbean, it is considered an exotic weed in many areas. Jiang Muyan pointed out in 2001 that P. parviflora was introduced to Southeast Asia in the late 1950s for the development of soil and water conservation cover plants, and subsequently spread to tropical Asia, Oceania and northern Australia.

Ecology

It is suitable for growing in areas where the annual average temperature is above 20 degrees Celsius; its plants grow vigorously when the soil moisture content is above 15%. It is basically a plant that loves moisture and has strong phototaxis. In 2000, Kong Guohui and others pointed out that P. floribunda grows particularly rapidly in growing areas with moist, loose soil, rich in organic matter and sufficient sunshine, but it is not tolerant of shade, dry and poor soil.

Others

In the early days of Malaysia, it was used as a ground cover, planted in landfills and barren places, but later it spread and caused disasters. It is known as "ecological killer" or "green cancer".

Morphology of the plant

1. Root :No special introduction

2. Stem :Stems are slender, creeping or climbing, multi-branched, pubescent or nearly hairless, green when young, nearly cylindrical, old stems are light brown with multiple ribs.

3. Leaf :The leaves in the middle part of the stem are triangular to ovate, 4 to 13 cm long and 2 to 9 cm wide. The base is heart-shaped, nearly halberd-shaped, the apex is acuminate, the edges have several coarse teeth or shallow wavy circular serrations, and both sides are hairless. , with 3 to 7 veins at the base, and the petiole is 2 to 8 cm long; the upper leaves become smaller and the petioles are shorter.

4. Flower :There are many flower heads, which are often arranged in a corymb shape at the branch ends. The peduncle is slender. The flowers on the top of the flower bloom first and then gradually open downward. The flower head is 0.45~0.6 cm long and contains 4 florets. All are strong bisexual flowers. There are 4 involucral bracts, narrow and oval in shape, apex acuminate, part acute, green, 0.2~0.45 cm long, and there are linear oval bracts (outer bracts) at the base of the involucre, 0.1~0.2 cm long. The flowers are fragrant; the corolla is white, tubular, 0.3~0.4 cm long, with a bell-shaped eaves and 5-toothed lobes.

5. Seed :No special introduction

6. Fruit :Achenes are 0.15~0.2 cm long, black, hairy, with 5 ribs and glands. The pappus is composed of 32~40 stinging hairs, white, 0.2~0.4 cm long.