Acalypha hispida: Structure and Function

Acalypha hispida is distinguishable by its fuzzy, bright red, and long flowers. It is commonly called the "chenille" plant, which is the french word for caterpillar. This plant is dioecious, which means that it produces both male and female flowers on separate plants, although only the female plants grow the iconic red flowers shown above. 

Despite its bright color, which is usually meant to attract bird or mammal pollinators, the plant is predominately pollinated by wind. The plant grows best in hot, humid climates, and it can flower at any time of year as long as the temperatures are warm enough. Although the plant is safe for house-pets, its sap is actually mildly toxic to humans.

Acalypha hispida: Evolutionary Relationships

The chenille plant originates from the South Pacific and thrives in moist and tropical climates. It is part of the Euphorbiaceae family, which is characterized by having unisex flowers and milky sap. Specifically, this sap is what causes skin irritation and indigestion in humans, and it likely evolved as a defense mechanism against animals that try to eat its flowers before the plant can produce and disperse seeds. This defense mechanism is also effective against most pests, except for spider mites--which are the biggest danger to this plant if it becomes too dry. However, although its red flowers are extremely distinguishable to humans, they cannot be easily seen by insects, which may be another evolutionary measure to help the chenille plant evade most pests.

Acalypha hispida: Ecology

Fortunately, the chenille plant is very common, especially because of its popularity as a houseplant. Since it depends on wind to pollinate, climate is the biggest factor limiting is dispersal and distribution. As a tropical plant, it grows best in hot, humid, and bright climates. If cared for as a houseplant, it thrives in temperatures over 60°F and should not be left to dry out completely, otherwise it is vulnerable to pests such as spider mites. 

Despite its mildly toxic sap, the chenille plant does provide ecosystem services to humans, which is any positive benefit that the natural environment provides to us. Studies have shown that its leaf extracts have significant anti-inflammatory activity and demonstrate antioxidant potential (Siraj et. al 2016).

Siraj MA, Shilpi JA, Hossain MG, Uddin SJ, Islam MK, Jahan IA, Hossain H. Anti-Inflammatory and Antioxidant Activity of Acalypha hispida Leaf and Analysis of its Major Bioactive Polyphenols by HPLC. Adv Pharm Bull. 2016 Jun;6(2):275-83. doi: 10.15171/apb.2016.039. Epub 2016 Jun 30. PMID: 27478793; PMCID: PMC4961989.