Giant Taro

Basic Information

Common Name: Giant Taro

Scientific Name: Alocasia macrorrhizos ‘Borneo Giant’

Native Habitat: Tropical rainforests of Southeast Asia, particularly Borneo.

History / Discovery / Cultivator

Alocasia macrorrhizos, commonly known as Giant Taro, Elephant Ear, or Cunjevoi, has a history deeply intertwined with the tropical regions of Southeast Asia and Australasia. While the exact origins of the ‘Borneo Giant’ cultivar are less precisely documented than the species itself, its lineage traces back to the wild Alocasia macrorrhizos, a plant long valued and utilized by indigenous communities for both food and medicinal purposes.

The ‘Borneo Giant’ cultivar, as its name suggests, likely originated from the island of Borneo. Borneo, a biodiversity hotspot, harbors an incredible variety of flora, including numerous Alocasia species and cultivars. The ‘Borneo Giant’ is distinguished by its exceptionally large leaves, even compared to other Alocasia macrorrhizos variants, making it a prized ornamental plant. It’s reasonable to assume that local horticulturalists or plant collectors in Borneo, recognizing the unique size and appeal of certain Alocasia macrorrhizos individuals, selectively propagated them, eventually leading to the emergence of the ‘Borneo Giant’ cultivar.

The history of Alocasia macrorrhizos itself is much older and more extensively documented. The plant has been cultivated in the tropics for centuries. Archaeological evidence suggests that taro-like plants were among the earliest crops cultivated by humans, dating back thousands of years. While Alocasia macrorrhizos isn’t true taro (which belongs to the genus Colocasia), it shares a similar edible corm when properly prepared, although it requires careful cooking to remove calcium oxalate crystals that can cause intense irritation.

The ‘Borneo Giant’s’ journey from the rainforest floor to global gardens is a more recent phenomenon. As interest in tropical foliage and exotic plants surged in the late 20th and early 21st centuries, plant collectors and nurseries actively sought out unusual and visually striking specimens. The ‘Borneo Giant’, with its dramatic size and architectural presence, quickly gained popularity. Its propagation and distribution were facilitated by advancements in plant tissue culture and international plant trade.

Today, the ‘Borneo Giant’ is cultivated worldwide in tropical and subtropical climates, as well as indoors as a houseplant in cooler regions. Its dramatic foliage makes it a focal point in gardens and a statement piece in indoor collections. While the specific individual or nursery responsible for the initial propagation and distribution of the ‘Borneo Giant’ may remain unknown, its success is a testament to the enduring appeal of impressive and unusual plant forms. Its continued popularity ensures that the ‘Borneo Giant’ will remain a celebrated cultivar within the Alocasia family for years to come.

Plant Care Summary

Botanical Insights

Adaptations

Alocasia macrorrhizos ‘Borneo Giant’ showcases several remarkable adaptations that contribute to its survival and thriving. Its enormous leaves are a primary adaptation to the shaded understory of rainforests. These broad leaves maximize light capture in dimly lit environments. The plant also possesses thick, fleshy stems (corms) that serve as storage organs for water and nutrients, enabling it to withstand periods of drought or nutrient scarcity. Furthermore, Alocasia species have evolved specialized structures called hydathodes on their leaf tips. These hydathodes allow the plant to release excess water through a process called guttation, helping to regulate internal water pressure in humid environments. The plant’s toxicity, stemming from calcium oxalate crystals, serves as a deterrent to herbivores. Finally, its ability to reproduce both sexually (through seeds) and asexually (through corm offsets) enhances its resilience and propagation potential.

Propagation Methods

Alocasia macrorrhizos ‘Borneo Giant’ can be effectively propagated through several methods. The most common method is division of the corm. This involves carefully separating offsets (smaller plants growing from the main corm) and potting them individually. Another method involves propagating from stem cuttings. Cut a healthy stem into sections, ensuring each section has at least one node. Allow the cut ends to callous over for a few days before planting in moist potting mix. Maintaining high humidity is crucial for successful propagation. While leaf cuttings are sometimes attempted, they are generally less reliable for Alocasia propagation. Seed propagation is also possible, but it’s a slower and less predictable process, often resulting in variations from the parent plant.

Toxicology

Alocasia macrorrhizos ‘Borneo Giant’ contains calcium oxalate crystals throughout its tissues, making it toxic to both humans and pets if ingested. These microscopic crystals are needle-shaped and cause intense irritation upon contact with mucous membranes. In humans, ingestion typically results in immediate burning sensations in the mouth and throat, excessive drooling, difficulty swallowing, and potential swelling of the tongue and airways. Contact with skin can also cause irritation and a rash. In pets, such as cats and dogs, the symptoms are similar: oral irritation, drooling, vomiting, and difficulty swallowing. While ingestion is rarely fatal, it can be extremely uncomfortable and may require medical attention, especially for young children or pets. It’s essential to keep this plant out of reach of children and pets and to wear gloves when handling it to avoid skin irritation.

Common Problems

Pests:

• Spider mites
• Aphids
• Mealybugs

Diseases:

• Root rot (due to overwatering)
• Fungal leaf spot

Other:

• Leaf yellowing (due to overwatering or nutrient deficiency)
• Browning tips (due to low humidity or inconsistent watering)
• Drooping leaves (due to underwatering or insufficient light)

Rarity & Value

Rarity:

While Alocasia macrorrhizos itself is not particularly rare, the ‘Borneo Giant’ cultivar, with its exceptionally large leaves, can sometimes be considered less common than other Alocasia varieties. Its rarity is often tied to its slower growth rate compared to other common houseplants and the fact that achieving its full potential size requires providing optimal growing conditions. Furthermore, consistent availability can be influenced by propagation success rates at nurseries, which in turn affect market supply. The demand for large, statement plants also contributes to its perceived rarity among collectors.

Value:

The value of an Alocasia macrorrhizos ‘Borneo Giant’ specimen is primarily influenced by its size and overall health. Larger plants with well-established root systems typically command higher prices. The condition of the leaves is also a crucial factor. Plants with pristine, undamaged foliage are more valuable than those with blemishes or imperfections. The maturity of the plant also plays a role, as older plants tend to have more developed corms and a more robust overall structure. Finally, current trends in the houseplant market influence demand, which in turn affects pricing. A surge in popularity of tropical foliage plants can drive up the value of desirable specimens like the ‘Borneo Giant’.