North America Native Plant

Green Caskfruit

Botanical name: Doliocarpus olivaceus

USDA symbol: DOOL

Life cycle: perennial

Habit: vine

Native status: Native to Puerto Rico  

Green Caskfruit: A Mysterious Native Vine from Puerto Rico If you’re looking for a conversation starter in your garden, you might have just found it! Green caskfruit (Doliocarpus olivaceus) is one of those plants that even seasoned gardeners probably haven’t heard of. This perennial climbing vine is a true Puerto ...

Green Caskfruit: A Mysterious Native Vine from Puerto Rico

If you’re looking for a conversation starter in your garden, you might have just found it! Green caskfruit (Doliocarpus olivaceus) is one of those plants that even seasoned gardeners probably haven’t heard of. This perennial climbing vine is a true Puerto Rican native that’s as intriguing as it is elusive.

What Exactly is Green Caskfruit?

Green caskfruit is a twining, climbing plant that develops woody stems over time. Think of it as nature’s version of a living rope – it loves to wind its way up trees, fences, or whatever sturdy support it can find. As a member of the Dilleniaceae family, it’s related to some pretty interesting tropical plants, though it tends to fly under the radar compared to its showier cousins.

Where Does It Call Home?

This vine is exclusively native to Puerto Rico, making it a true island endemic. You won’t find wild populations anywhere else in the world, which makes it pretty special if you think about it. In Puerto Rico, it grows naturally in the island’s diverse ecosystems, though specific habitat details are surprisingly scarce in botanical literature.

Should You Grow Green Caskfruit?

Here’s where things get interesting – and a bit challenging. While green caskfruit has the appeal of being a unique native plant, it’s also what you might call a mystery vine. Very little information exists about its cultivation requirements, growth habits, or even what it looks like when it flowers and fruits.

The Reality Check

If you’re considering adding green caskfruit to your garden, you should know that you’d essentially be pioneering its cultivation. Here’s what we do and don’t know:

What We Know:

  • It’s a perennial climbing vine
  • It develops woody stems
  • It’s native to Puerto Rico
  • It belongs to the Dilleniaceae family

What Remains a Mystery:

  • Specific growing conditions and soil preferences
  • USDA hardiness zones (though likely tropical/subtropical)
  • Flower and fruit characteristics
  • Wildlife and pollinator benefits
  • Propagation methods
  • Growth rate and mature size

Alternative Native Climbing Options

If you’re drawn to the idea of a native climbing plant but want something with more reliable growing information, consider looking into other native vines from your region. For tropical and subtropical gardens, there are many well-documented native climbers that can provide similar structure and habitat benefits with much more predictable results.

The Bottom Line

Green caskfruit represents one of those fascinating gaps in our horticultural knowledge. While its native status makes it ecologically valuable, the lack of cultivation information makes it a challenging choice for most gardeners. If you do manage to encounter this plant or find seeds, consider yourself lucky – you might just be helping to unlock the secrets of successfully growing this Puerto Rican endemic.

For now, green caskfruit remains more of a botanical curiosity than a practical garden addition. But who knows? Maybe you’ll be the gardener who figures out how to grow it successfully and shares that knowledge with the rest of us!

Green Caskfruit

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Dilleniales

Family

Dilleniaceae Salisb. - Dillenia family

Genus

Doliocarpus Roland. - caskfruit

Species

Doliocarpus olivaceus Sprague & R.O. Williams ex Standl. - green caskfruit

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