What Is Sphagneticola trilobata? An Introduction to Its Benefits, Effects and Cultivation Methods

Sphagneticola trilobata, an evergreen herbaceous plant, blooms all year round, its round lotus-like form grows rapidly, its reproductive capacity is extremely strong, and it rarely suffers from pests or diseases. So what exactly is the “invasive species” Sphagneticola trilobata? What benefits and effects does it have? How is it cultivated?

1. What Is Sphagneticola trilobata

Sphagneticola trilobata was first introduced to Hong Kong, China in the 1870s to replace the traditional Chinese medicinal herb Wedelia chinensis. In southern China, Sphagneticola trilobata is often used as a ground cover plant. However, because of its vigorous spreading ability, it often overgrows into a dense ground cover, crowding out and preventing the regeneration of other plants and disrupting the balance of the ecosystem it occupies. It is widely distributed in southern China and threatens local species diversity, including on Hainan Island. Thanks to its rapid growth, Sphagneticola trilobata typically over-covers local vegetation in open areas disturbed by humans, such as roadsides, farmland, pastureland and abandoned land. Sphagneticola trilobata holds an absolutely dominant position over local vegetation, especially the herbaceous layer; once it becomes established locally, it inhibits the growth and regeneration of other plants. Therefore, Sphagneticola trilobata has become a harmful weed in China and has been listed as one of the “100 of the World's Worst Invasive Alien Species”.

2. The Main Value of Sphagneticola trilobata — Landscaping

Sphagneticola trilobata has emerald-green leaves and pale yellow flowers, and in the south it blooms almost all year round. It is easygoing in nature, has few pests and diseases, grows quickly, tolerates drought and damp, and propagates easily, so it is deeply loved by people. It is extremely widely used in landscaping, often as a ground cover plant to adorn wall corners and enrich the plant landscape, and as a slope-protection plant; it is an excellent flowering ground cover and slope-protection plant.

Experiments have shown that using Sphagneticola trilobata for vegetation restoration on steep cliffs, riverbanks, abandoned farmland, mines and landfills has fairly good results. Because its dense creeping community and its intricate root system and many adventitious roots form a network that consolidates the soil, its ecological benefit for soil and water conservation is significant. Sphagneticola trilobata also has a certain tolerance to urban landfill leachate and has a fairly good ability to purify and remediate soil polluted by leachate, so it can be used as a material for vegetation reconstruction at landfill sites.

3. The Pharmacological Effects of Sphagneticola trilobata

Research into the components of Wedelia chinensis has found that it mainly contains compounds such as triacontanoic acid and stigmasterol glucoside, and its main pharmacological effects are anticancer and antibacterial activity; studies show that it inhibits the activity of Corynebacterium diphtheriae, Staphylococcus aureus and beta-hemolytic Streptococcus.

Besides its good ornamental value, Wedelia chinensis also has considerable medicinal value, and medical works record quite a lot about it. Below, the editor introduces a few of the more common application prescriptions:

1. To treat diphtheria: 2 liang (about 100 g) of fresh Wedelia chinensis, 2 qian (about 6 g) of licorice, 5 fen (about 1.5 g) of ricepaper pith. Decoct in water and take as a concentrated decoction, 1 to 4 doses a day. Separately, pound fresh Wedelia chinensis and squeeze out the juice, add vinegar equal to one quarter of the amount of the liquid, dip a cotton swab in the liquid and apply it to the pseudomembrane, 2 to 3 times a day. (Fujian Chinese Herbal Medicine)

2. To prevent diphtheria: pound fresh Wedelia chinensis and squeeze out the juice, add vinegar equal to one quarter of the amount of the liquid, and spray it into the throat or use it as a mouthwash, 1 to 2 times a day for three consecutive days. (Fujian Chinese Herbal Medicine)

3. To treat dysentery: 30 g of Wedelia chinensis, 15 g each of goose-foot fern and Osbeckia chinensis. Decoct in water and take.

4. To treat pneumonia: 60 g each of Patrinia scabiosifolia and Polygonum chinense, 30 g each of Wedelia chinensis and Justicia procumbens. Decoct in water and take.

5. Precautions

(1) Although Wedelia chinensis can be used medicinally and is not particularly toxic, it should only be used under the guidance of an experienced physician.

(2) Wedelia chinensis is cool in nature, so people with a cold-deficient constitution should use it with caution.

4. Cultivation Techniques for Sphagneticola trilobata

1. Cultivation of Sphagneticola trilobata on abandoned coal mine land

Under natural conditions, Sphagneticola trilobata has the potential for vegetative reproduction throughout its entire growth period. Cutting experiments show that as long as there is a stem segment with a node, it has the potential to develop into a complete plant under suitable conditions. This reflects the growth pattern of Sphagneticola trilobata: after a creeping stem grows to a certain length, adventitious roots grow from its nodes and new young branches sprout. In this way, a Sphagneticola trilobata population can multiply and spread in large numbers within a relatively short time, continuously occupying new space, which helps accelerate the process of vegetation restoration.

Sphagneticola trilobata has strong morphological plasticity and a highly divergent, adaptable nature. It has fairly broad ecological tolerance or plasticity, with plastic responses to variable conditions. In poor coal gangue soil habitats, individual plants are short and compact with short internode spacing, yet they can complete vegetative and reproductive growth normally and flower and set seed abundantly. Sphagneticola trilobata can adapt to growth in poor coal gangue soil environments, showing strong tolerance and broad adaptability.

Sphagneticola trilobata grows well under both semi-shade and full-sun conditions; it tolerates drought and damp, the plants grow quickly, and its ecological niche is extremely broad. The plants tolerate poor soil but especially like environments with good water and nutrient conditions. In addition, surveys of the distribution of Sphagneticola trilobata and its main communities show that the population has the greatest niche breadth in terms of ecological factors such as slope, soil thickness, soil water content, soil pH value and light intensity, indicating that its requirements for environmental conditions are not high and that it can broadly adapt to various habitats. Through comparative planting experiments, there was no obvious difference in biomass between the two groups. Therefore, Sphagneticola trilobata is a preferred plant for vegetation reconstruction on abandoned coal mine land.

Sphagneticola trilobata grows rapidly. Experimental results show that as long as water and soil conditions are suitable, Sphagneticola trilobata can grow and reproduce rapidly in both fertile loam and poor coal gangue soil. During hot, humid seasons the plants grow faster, and short-term rainfall benefits plant growth.

In summary, Sphagneticola trilobata can grow normally in coal gangue; the plants are relatively short, flower abundantly and grow relatively slowly, and after a period of growth and reproduction they can form a community, which is beneficial for soil and water conservation and vegetation restoration, so it can definitely be applied to vegetation restoration on abandoned coal mine land. 

2. Cultivation of Sphagneticola trilobata on abandoned rare earth mine land

Factors affecting the growth of Sphagneticola trilobata under laboratory conditions

(1) Humidity: Sphagneticola trilobata likes a slightly humid climate and requires the relative air humidity of its growing environment to be 50%-70%. Humidity can be increased by misting the cuttings, 1 to 3 times a day.

(2) Temperature: The optimum temperature for rooting Sphagneticola trilobata cuttings is 18-25°C. Below 18°C, rooting of cuttings is difficult and slow; above 25°C, the cut ends of the cuttings are easily infected by pathogens and rot, and the higher the temperature, the greater the proportion that rot.

(3) Light: Cutting propagation cannot do without sunlight, but the stronger the light, the higher the temperature inside the cuttings, the more vigorous the transpiration inside the stems, and the more water is consumed, which is not conducive to the survival of the cuttings.

Factors affecting the growth of Sphagneticola trilobata under field cultivation conditions

Besides the factors above, under field growth conditions water is the main limiting factor for the growth of Sphagneticola trilobata. Sphagneticola trilobata is a shade-loving plant, and ensuring ample watering in the early planting stage can make it grow quickly.

3. Management of Sphagneticola trilobata after field cultivation

The volatile compounds of Sphagneticola trilobata can produce allelopathic effects on neighbouring plants, possibly by reducing the chlorophyll content of the receptor plants through these volatiles, leading to a lower net photosynthetic rate, and the plant's self-protection mechanism is also relatively reduced, so that the root length, seedling height and fresh weight of the receptor plants decrease and the plants become shorter. Therefore, after cuttings are planted in abandoned rare earth mining areas, corresponding management should be carried out to prevent Sphagneticola trilobata from growing rampantly, for example by cultivating it together with Ageratum conyzoides. Because Ageratum conyzoides has a fairly good remediation effect on Cd, Zn and Mn pollution in tailings soil, and has strong adaptability, fast growth and a large overall biomass, it can also be selected as a remediation plant for mining area soil. 

4. Pests and diseases

Sphagneticola trilobata has relatively few insect pests, but it is sometimes harmed by pests such as red spider mites, aphids and cutworms. Omethoate at 200 times dilution or 40% acephate-methyl parathion emulsion can be used for control. There are two common diseases: powdery mildew and leaf spot. Because it grows too vigorously, rotting leaves easily form at the base of its rhizomes, causing poor ventilation and high humidity, which makes it prone to powdery mildew. In the early stages of infection, the leaves and young shoots of the plant show powdery white mottling, or are covered with a white powdery layer. Leaf spot is caused by the pest-related fungus Corynespora cassiicola and causes the leaves to wither. Diseases of Sphagneticola trilobata should be prevented mainly through prevention. Attention should be paid to using a brush cutter or carrying out regular manual pruning to remove rotten branches; in the summer peak growing season, prune once every 10-15 d. In hot, humid environments, when this symptom appears, apply a certain amount of carbendazim, a 50% wettable powder at 1000-1500 times dilution, spraying once every 7-10 d for 2-5 consecutive sprays, and spray again after rain.