North America Non-native Plant

Thollon’s Strophanthus

Botanical name: Strophanthus thollonii

USDA symbol: STTH4

Native status: Not native but doesn't reproduce and persist in the wild

Thollon’s Strophanthus: A Mysterious African Native If you’ve stumbled across the name Thollon’s strophanthus (Strophanthus thollonii), you’re likely encountering one of the more elusive members of the plant kingdom. This African native belongs to the Strophanthus genus, a group known for their distinctive twisted flower petals and interesting botanical properties. ...

Thollon’s Strophanthus: A Mysterious African Native

If you’ve stumbled across the name Thollon’s strophanthus (Strophanthus thollonii), you’re likely encountering one of the more elusive members of the plant kingdom. This African native belongs to the Strophanthus genus, a group known for their distinctive twisted flower petals and interesting botanical properties.

What We Know About This Mysterious Plant

Thollon’s strophanthus is part of the Apocynaceae family, which includes many tropical and subtropical flowering plants. While its botanical relatives are better documented, this particular species remains somewhat of an enigma in horticultural circles.

The plant appears to be native to tropical regions of Africa, though specific geographical details about its natural distribution are limited in available literature.

The Challenge of Growing Unknown Species

Here’s where things get tricky for gardeners: there’s remarkably little documented information about successfully cultivating Strophanthus thollonii. Unlike many popular garden plants, this species hasn’t made its way into common cultivation, which means we lack the usual growing guides and care instructions.

What we can infer from related Strophanthus species is that these plants typically prefer:

  • Warm, tropical or subtropical climates
  • Well-draining soil
  • Protection from harsh winds
  • Consistent moisture during growing season

Should You Try Growing It?

The honest answer is that growing Thollon’s strophanthus presents significant challenges for most gardeners. Without clear information about its specific needs, hardiness zones, or even reliable sources for obtaining the plant, it’s not a practical choice for typical home gardens.

If you’re drawn to African native plants with similar characteristics, consider these better-documented alternatives:

  • Adenium species (Desert Rose) for succulent-like tropical appeal
  • Plumeria species for fragrant tropical flowers
  • Catharanthus roseus (Madagascar Periwinkle) for continuous blooms

A Plant for Specialists

Thollon’s strophanthus might be better suited for botanical gardens, research institutions, or very experienced collectors who specialize in rare African flora. These settings have the resources and expertise to experiment with growing conditions and potentially contribute to our understanding of this mysterious species.

The Bottom Line

While Thollon’s strophanthus certainly piques botanical curiosity, the lack of available growing information makes it impractical for most gardeners. Sometimes the most honest advice is to admire a plant from afar and choose better-understood species for your garden adventures.

If you’re passionate about African native plants, focus on well-documented species that will give you the best chance of success while still providing that exotic appeal you’re seeking.

Thollon’s Strophanthus

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Gentianales

Family

Apocynaceae Juss. - Dogbane family

Genus

Strophanthus DC. - strophanthus

Species

Strophanthus thollonii Franchet - Thollon's strophanthus

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA