TheNaturePlanet

In the diverse world of flowers, apart from their stunning blossoms, the root systems of moth orchids (Phalaenopsis) are equally intriguing. These roots, varying in form, are not only crucial for the plant's survival but also serve unique biological functions.

Moth orchid roots can be primarily divided into aerial roots and underground roots based on their appearance and function. However, as a typical epiphytic orchid, the underground roots of moth orchids are less noticeable in artificial cultivation. The most commonly observed and focused-on roots in daily care are the aerial roots.
Aerial Roots
Aerial roots are the most distinctive feature of moth orchids. They emerge from the stem and grow exposed in the air. Newly formed aerial roots are tender green in color, with smooth surfaces and translucent growth tips at their ends, exuding vitality. As they grow, these roots gradually turn white, their epidermis becomes rough, and they can extend to tens of centimeters or even longer. Curved and flexible like agile threads, these aerial roots stretch freely in the air, not only adding ornamental value but also reflecting the unique growth habits of moth orchids.
Key Functions of Moth Orchid Roots
Despite their unique morphology, moth orchid roots serve multiple important roles that are vital for the plant’s growth, development, and survival:
1. Water Absorption
Moth orchids are native to the trunks of rainforest trees or rocky surfaces, where air humidity is high but there is no fixed soil to supply water. The epidermis of aerial roots has a unique structure called the velamen, composed of multiple layers of loose cells that resemble a sponge. This allows them to quickly absorb moisture from the air, including fog, rainwater, and even artificially sprayed mist. After absorbing water, the velamen transports it to the vascular tissues inside the roots, which then distribute it to all parts of the plant to meet the water needs of physiological activities such as growth and blooming. In home cultivation, it is common to see aerial roots change from white to light green after absorbing water—a visual sign of their water uptake.
2. Nutrient Uptake
In natural environments, besides water, aerial roots of moth orchids can also absorb nutrients from the surfaces of host trees, organic particles floating in the air, and nutrients carried by rainwater. These nutrients include macronutrients like nitrogen, phosphorus, and potassium, as well as micronutrients like iron, zinc, and manganese. Root hairs on the surface of aerial roots collaborate with microbial communities to decompose and absorb these nutrients. In artificial cultivation, by regularly applying specialized orchid nutrient solutions, gardeners enable aerial roots to efficiently uptake nutrients, providing ample energy for the plant’s growth, flower bud differentiation, and blooming.
3. Plant Anchoring
As epiphytic plants, moth orchids rely on aerial roots to anchor themselves to surfaces like tree trunks or rocks. Aerial roots secrete mucus that enhances adhesion when in contact with the substrate. Meanwhile, the roots grow and twine along the surface of the substrate, gradually forming a firm anchoring structure. In potted home gardens, aerial roots twine around substrates like sphagnum moss or bark, keeping the plant stable in the pot, resisting external disturbances, and providing a stable foundation for normal growth and development.
4. Photosynthesis
Some young aerial roots contain chlorophyll in their epidermal cells, allowing them to perform photosynthesis under light. Although the organic matter produced by aerial roots through photosynthesis is relatively less than that by leaves, it can still provide extra energy and nutrients for the plant, helping to enhance its growth potential—especially during the early growth stage or when leaves are damaged.

The unique root types and powerful functions of moth orchids are key to their survival and reproduction. Whether in natural environments or artificial cultivation, these roots silently play essential roles in supporting the growth and beautiful blooming of the plant. When caring for moth orchids, we should not only admire their leaves and flowers but also pay attention to the health and vitality of their roots, providing them with a suitable growing environment.