Zantedeschia

Basic Information

Common Name: Zantedeschia
Scientific Name: Zantedeschia
Native Habitat: Primarily South Africa, encompassing regions from the Cape Provinces to the KwaZulu-Natal province. Specific species have adapted to varying conditions within this range, from wetland areas to drier slopes.

History / Discovery / Cultivator

The genus Zantedeschia, encompassing the popular calla lilies, carries a fascinating story entwined with botanical exploration and horticultural evolution. The plant’s story begins with the Italian botanist Giovanni Zantedeschi, a 19th-century figure in the realm of botany. The genus was later named in his honor, recognizing his contributions to the field of plant classification.

The discovery and initial documentation of various Zantedeschia species are attributed to European botanists and plant collectors, particularly those active during the 18th and 19th centuries. These explorers, drawn to the Cape region of South Africa, diligently collected specimens and cataloged new species, including the ancestors of the calla lilies that would become beloved worldwide. Their efforts paved the way for the eventual classification and study of these remarkable plants.

The propagation and cultivation of Zantedeschia species, particularly the Zantedeschia aethiopica, a well-known species, gained traction in the Victorian era. The plant’s elegant form and graceful white spathes resonated with the Victorian sensibilities. It quickly found favor as a decorative element, gracing gardens and greenhouses across Europe and North America.

While the precise origins of hybridisation are challenging to pinpoint, the desire to enhance Zantedeschia led to the development of various cultivars, extending beyond the original white form. Over time, plant breeders began introducing and stabilizing an array of colours, ranging from vibrant yellows and oranges to pinks, purples, and even near-black shades. These innovations expanded the appeal of Zantedeschia, transforming it from a simple garden plant into a sought-after ornamental.

The geographical origins of the various Zantedeschia species provide another significant dimension. The calla lilies are predominantly native to the southern parts of Africa, specifically to wetland regions and along the banks of streams, showcasing their adaptation to varied climates. The ability of the plant to thrive in climates ranging from cool to mild has assisted in its adoption throughout the world. This diversity is vital to understanding the plant’s care requirements.

Plant Care Summary

Botanical Insights

Adaptations

Zantedeschia plants exhibit fascinating adaptations that contribute to their survival in their native environments. The most noticeable adaptation is the presence of a rhizome, which is a modified underground stem that serves as a storage organ, allowing the plant to survive during unfavorable periods. The rhizome stores water and nutrients, helping the plant to re-emerge during the growing season. Another adaptation is the large, waxy leaves that help capture sunlight efficiently and regulate moisture loss. In addition, the plant’s flowers, with their colorful spathes (modified leaves), are designed to attract pollinators, ensuring successful reproduction. The different variations of these blooms and their varied colors demonstrate a high level of adaptation.

Propagation Methods

Zantedeschia can be propagated through several methods. Division is a common technique, involving the careful separation of the rhizomes during the dormant period. Each divided section should have at least one growing point. Another method is by seed, which is useful for creating new cultivars and hybrids. Germination typically requires a specific temperature range and consistent moisture. Finally, some Zantedeschia can be propagated through offsets, which are small, secondary plants that grow from the parent rhizome, offering an easy way to expand the plant collection.

Toxicology

Zantedeschia plants contain calcium oxalate crystals, which are irritating when ingested. If ingested by humans or pets, it can cause symptoms such as oral irritation, excessive salivation, and difficulty swallowing. In severe cases, it can cause swelling of the mouth and throat. It’s best to keep these plants out of reach of children and pets, and to seek veterinary or medical assistance if ingestion is suspected.

Common Problems

Pests:

• Aphids
• Spider mites
• Mealybugs

Diseases:

• Bacterial soft rot
• Rhizome rot
• Leaf spot

Other:

• Leaf yellowing and potential drop: Overwatering and poor drainage.
• Browning tips: Low humidity, lack of watering or fertilizer burn.
• Failure to bloom: Insufficient light, improper dormancy period, or lack of nutrients.

Rarity & Value

Rarity:

Certain Zantedeschia cultivars are considered rare due to various factors. Novelty in color or form often makes them more desirable. The propagation difficulty, slower growth rates of some cultivars, and the specific growing conditions required, can affect the supply. Furthermore, limited availability is frequently due to the small-scale nature of specialized breeding programs. Specific mutations and variegations can be difficult to stabilize, making the plants they appear on harder to find.

Value:

The market value of Zantedeschia specimens is influenced by several factors. Plant size, with larger plants often being valued higher, can drive a higher sale price. The quality and stability of the variegation play an important part in the sale price. Current collector trends and the rarity of specific cultivars also affect value, as does the maturity of a specimen. The provenance and reputation of the seller can affect the price, as well.