Homalomena rubescens ‘Black Emerald’

Origin of Homalomena rubescens ‘Black Emerald’

‘Black Emerald’ is a dark-leaved horticultural selection of Homalomena rubescens. The species occurs naturally from Sikkim through Assam and Bangladesh to Myanmar, where it grows in wet tropical habitats.

Growing Homalomena rubescens ‘Black Emerald’

• Light: Give medium to bright filtered light and protect the leaves from strong direct sun.
• Water: Rewater as the surface starts to dry while the pot still holds some moisture deeper down. Soak the mix evenly and let it drain completely.
• Potting mix: Use an airy mix with bark and perlite or pumice that holds some moisture around the roots.
• Growth and repotting: The upright clump is naturally self-supporting. Repot into a slightly larger container once roots circle the pot or new growth from the base fills the surface.
• Room climate: Keep established plants warm with stable temperatures and average to moderately high humidity.
• Feeding: Give a light, regular feed while the plant is producing new leaves. Feed less often when growth slows.
• Propagation: Separate well-rooted sections from a mature clump.

Common issues with Homalomena rubescens ‘Black Emerald’

• Fine pale dots or webbing appear on the dark leaves: Spider-mite damage can stand out clearly against the dark foliage. Check the leaf undersides, isolate the plant and use a labelled mite treatment at the stated repeat interval.
• Dry brown margins build across several leaves: Check whether the potting mix is drying completely, the leaves are receiving hot direct sun, or the plant is exposed to warm dry airflow. Correct whichever condition applies.
• Yellowing is paired with soft roots or bases of the leaf stalks: The potting mix may be staying wet for too long. Cut rot back to firm healthy tissue with a clean tool, discard the damaged material and repot in fresh, airy potting mix.
• Sticky residue, hard bumps or cottony patches appear around the leaf stalks: Check for scale or mealybugs. If you find them, isolate the plant, remove visible pests and use a treatment labelled for the pest, repeating it at the interval stated on the label.

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.