Phlogacanthus

Description

Phlogacanthus is a genus of flowering plants in the family Acanthaceae. The genus consists of about 20 species of evergreen shrubs and small trees that are native to Southeast Asia, India, and China. These plants are known for their beautiful flowers that bloom in shades of pink, red, and purple. The name Phlogacanthus is derived from the Greek words “phlogein” meaning “to burn” and “akantha” meaning “thorn,” referring to the thorn-like structures on the stems of these plants.

Taxonomic Information

Domain	Eukaryota
Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Lamiales
Family	Acanthaceae
Genus	Phlogacanthus

Appearance

Phlogacanthus plants have glossy, dark green leaves that are arranged in opposite pairs along the stems. The flowers are borne in clusters at the tips of the stems and are tubular in shape, with five petals that flare out at the end. The flowers are typically pink, red, or purple and are quite showy, making these plants a popular choice for gardens and landscaping. The plants can grow up to 10 feet tall and 6 feet wide, so they need plenty of space to thrive.

Care Guide

Water: Phlogacanthus plants prefer moist but well-drained soil. Water deeply once a week during the growing season, and reduce watering in the winter.

Fertilization: Fertilize with a balanced fertilizer once a month during the growing season.

Soil: These plants prefer rich, well-drained soil. Amend the soil with compost before planting.

Sunlight: Phlogacanthus plants prefer partial shade to full sun.

Hardiness Zones: Phlogacanthus plants are hardy in USDA zones 9 through 11.

Common Pests & Diseases

Phlogacanthus plants are generally healthy and disease-resistant, but they can be susceptible to spider mites, whiteflies, and mealybugs. If you notice any signs of infestation, treat the plants with an insecticidal soap or neem oil spray. These plants are also susceptible to root rot if they are overwatered or planted in poorly-drained soil.

Habitat

Phlogacanthus plants are native to Southeast Asia, India, and China. They are often found growing in tropical and subtropical forests, in areas with high humidity and rainfall.

Question and Answer

Q: How often do I need to water Phlogacanthus plants?

A: Water deeply once a week during the growing season, and reduce watering in the winter.

Q: What kind of soil do Phlogacanthus plants prefer?

A: These plants prefer rich, well-drained soil. Amend the soil with compost before planting.

Q: Can Phlogacanthus plants be grown in full sun?

A: Yes, these plants can be grown in full sun, but they also do well in partial shade.

Q: Are Phlogacanthus plants hardy?

A: Yes, these plants are hardy in USDA zones 9 through 11.

Related Plants

• Acanthus mollis
• Acanthus montanus
• Justicia carnea
• Ruellia

References

• “Phlogacanthus.” The Plant List, www.theplantlist.org/1.1/browse/A/Acanthaceae/Phlogacanthus/.
• Wong, S.-Y., et al. “Floral Biology of Phlogacanthus curviflorus Nees (Acanthaceae).” Journal of Tropical Forest Science, vol. 21, no. 2, 2009, pp. 116-120.
• Yamazaki, J., et al. “Two New Species of Phlogacanthus (Acanthaceae) from Thailand.” Kew Bulletin, vol. 73, no. 2, 2018, pp. 1-10.