Philodendron callosum · Plant reference

About

Philodendron callosum is an epiphytic aroid of wet forests in northern South America. Its glossy, leathery leaves have made it a houseplant.

Pet safety: Toxic to cats, dogs and horses: insoluble calcium oxalate crystals cause mouth pain and swelling, drooling, difficulty swallowing and, in cats and dogs, vomiting (ASPCA, for philodendrons). General guidance for the genus
People: Harmful if eaten: calcium oxalate crystals cause pain and swelling of the mouth, lips, tongue and throat; the sap can irritate skin. General guidance for the genus

Light: Bright indirect light; direct sun can scorch the leaves. General guidance for the genus
Water: Keep the soil evenly moist but never waterlogged; overwatering leads to root rot. General guidance for the genus
Humidity: Prefers high humidity but adapts to average indoor levels; a humidifier or pebble tray helps in dry rooms. General guidance for the genus
Temperature: About 18–29 °C (65–85 °F); keep away from cold draughts. General guidance for the genus
Soil: Moist, well-drained mix rich in organic matter. General guidance for the genus
Propagation: Stem cuttings or layering. General guidance for the genus
Hardiness: Frost-tender; grown outdoors only in USDA zones 10a–12a, elsewhere as a houseplant. General guidance for the genus

“General guidance for the genus” marks advice sourced for the genus as a whole rather than this species.

Leaves are leathery and glossy.

Wet forests of northern South America, growing as an epiphyte.

Its inflorescences release scent compounds, including dihydro-β-ionone, that attract its pollinators, scarab beetles of the genus Cyclocephala.

Grown as a houseplant for its shiny, tough foliage.

Difficulty: Not recorded
Temperature: About 18–29 °C (65–85 °F); keep away from cold draughts.
Humidity: Prefers high humidity but adapts to average indoor levels; a humidifier or pebble tray helps in dry rooms.