Begonia blancii — mottled form

A rock-dwelling Begonia from Palawan

Begonia blancii is known from forest near Bulalakaw Falls on Palawan in the Philippines. The mottled designation describes this cultivated foliage form.

In nature, the creeping plants cling directly to the shaded sides of small boulders beneath primary forest, often with almost no soil. Palawan has a marked dry season, and this rock-rooted habitat combines humid forest shade with exceptional drainage and little stored moisture around the roots.

Light and moisture for textured foliage care

Light

Give Begonia blancii, mottled form a position close to a clear east window or just outside the direct beam of a brighter south or west window. Very low light weakens growth, while stronger direct sun can scorch the leaves.

Watering

Begonia blancii, mottled form is ready for water after the upper third of the shallow mix has dried, before the fleshy leaves begin to soften. The fleshy leaves of Begonia blancii should remain firm between waterings.

Airflow and root care

Winter ventilation should not blow across damp roots or soft new leaves.

Humidity and airflow

Keep the humidity around Begonia blancii, mottled form steady. A steady moderate to high humidity supports clean growth, but saturated still air is unnecessary for the fleshy foliage.

Fertilising

Apply a very dilute complete foliage fertiliser to Begonia blancii only during active growth. Begonia blancii, mottled form grows best with light feeding.

Repotting

Give Begonia blancii, mottled form a new pot when rooted stems have filled the surface, water no longer wets the small root zones evenly or the organic fraction has broken down. The short roots tear easily when peeled from rock or coarse particles.

Common problems with Begonia blancii, mottled form

Natural mottling is joined by bleached patches

The light and dark marbling is inherited and remains firm. Sun scorch usually leaves a flat cream-tan patch on the exposed side. Disease usually begins as a glassy or dark lesion that keeps enlarging. Move a scorched plant into filtered light. Isolate the plant and remove a leaf only when a lesion continues to spread.

Paddle-shaped leaves wrinkle

The semi-succulent blades wrinkle when they lose water. Water thoroughly if the root ball is partly dry and the roots are firm. Persistent wrinkling or drooping in wet mix needs a check for brown, soft roots and better aeration.

Leaves become translucent and soft

Cold injury, prolonged wetness or rot can turn the compact leaves glassy before they collapse. Remove affected leaves and check the creeping base. If the rhizome is firm, allow the mix to drain and begin to dry and keep the plant warm and stable. Softness entering the rhizome is urgent: cut back to firm, healthy tissue and save a healthy leaf or tip.

Creeping rhizome darkens

Older rhizome skin may be brown, but it should resist gentle pressure. A wet section that gives under a finger or smells unpleasant is decaying beneath the compact foliage. Remove the whole soft area with a clean blade, then set the remaining firm piece at the surface of fresh, open mix.

Scarred or misshapen compact leaves

Check the centre and leaf undersides for thrips, broad mites and mealybugs. Feeding scars cross the natural mottling and may be accompanied by black specks, cottony deposits or hardened growth. Isolate the plant before treatment and use a gentle, labelled product; the small semi-succulent leaves can be marked by strong contact sprays.

Begonia blancii, mottled form is toxic to people and pets

• Keep this plant away from children, cats and dogs.
• The roots and rhizomes contain the highest levels of soluble oxalates, and the sap can irritate skin.
• Chewing may cause mouth irritation, drooling, vomiting or stomach pain. Contact a veterinarian or medical professional if symptoms develop.

Where does the name Begonia blancii come from?

Begonia honours Michel Bégon. The epithet blancii honours French botanist and plant specialist Patrick Blanc.

Carl Linnaeus established the genus Begonia in 1753 in Species Plantarum, page 1056.

Mark Hughes and Ching I. Peng first described Begonia blancii in 2011 in Botanical Studies (Taipei), volume 52, page 204.