Homalomena rubescens ‘Black Emerald’

Origin and habitat

Homalomena rubescens has a broad native range from the eastern Himalaya through southern China to mainland South-East Asia. It grows on the floor of warm tropical and subtropical forest in moist, humus-rich ground. Loose organic matter keeps air spaces open around the roots even while the ground remains damp.

Light and moisture for aroid care

• Position and light: Use medium to bright indirect light and keep the plant out of strong direct sun. A persistently dim position slows growth.
• Warmth and humidity: A steady indoor warmth and moderately humid to humid air suit this plant. Protect it from cold airflow and direct sources of heat.
• Watering: Water when the upper layer has dried while the centre remains lightly moist. Soak the complete root ball and let the surplus drain; do not allow the fine roots to dry hard or sit in a permanently saturated pot.
• Nutrients: Provide dilute feed in response to active growth rather than the calendar. When leaves continue developing in winter, continue at a lower frequency.
• Container and roots: Move up only one container size when the root ball and basal growth become crowded. Preserve the existing planting level.

Troubleshooting Homalomena rubescens ‘Black Emerald’

A new leaf opens greener than the older foliage: Fresh leaves can deepen in colour as they harden. Wait until the leaf has fully matured before treating the difference as a problem.

A yellow leaf begins to soften at the stalk: Wet, cool substrate may be damaging the roots or crown. Check drainage immediately and inspect the base for soft tissue.

Pale specks appear on the dark leaves: Spider mites can shelter beneath overlapping leaves and around petiole junctions, producing a fine dull stipple. Keep the plant apart, treat the lower surfaces, petiole bases and emerging rolls, and repeat only at the interval stated for the pest found.

Homalomena rubescens ‘Black Emerald’ is toxic to people and pets

• Keep this plant away from children, cats and dogs.
• Its leaves and stems contain insoluble calcium oxalate crystals, which can irritate the mouth, throat, skin and eyes.
• Chewing may cause burning pain, drooling, swelling, vomiting or difficulty swallowing. Contact a veterinarian or medical professional after exposure, especially if swelling or breathing problems occur.

Who first published Homalomena rubescens, and what does the name mean?

Homalomena combines Greek homalos, meaning flat, with mene, meaning moon. Rubescens means becoming reddish and refers to the red-toned petioles.

Heinrich Wilhelm Schott established the genus Homalomena in 1832 in Meletemata Botanica, page 20.

William Roxburgh first described it as Calla rubescens in 1832 in Flora Indica, 1832 edition, volume 3, page 515. Karl Sigismund Kunth later placed it in Homalomena as Homalomena rubescens in 1841 in Enumeratio Plantarum, volume 3, page 57.