North America Native Plant

San Lorenzo Milkvine

Botanical name: Matelea borinquensis

USDA symbol: MABO3

Life cycle: perennial

Habit: vine

Native status: Native to Puerto Rico  

San Lorenzo Milkvine: A Rare Puerto Rican Native Worth Discovering If you’re passionate about native plants and happen to garden in Puerto Rico, you might want to get acquainted with San Lorenzo milkvine (Matelea borinquensis). This perennial herb represents one of Puerto Rico’s unique botanical treasures, though it’s certainly not ...

San Lorenzo Milkvine: A Rare Puerto Rican Native Worth Discovering

If you’re passionate about native plants and happen to garden in Puerto Rico, you might want to get acquainted with San Lorenzo milkvine (Matelea borinquensis). This perennial herb represents one of Puerto Rico’s unique botanical treasures, though it’s certainly not the showiest plant you’ll encounter on the island.

What Makes San Lorenzo Milkvine Special

San Lorenzo milkvine is a forb herb, meaning it’s a non-woody perennial plant that dies back to ground level each year but returns from its root system. Unlike the towering trees that dominate Puerto Rico’s landscape, this humble plant stays close to the ground, lacking the thick, woody stems of shrubs and trees.

As a member of the milkvine family, this plant gets its name from the milky sap that flows when stems or leaves are damaged. This characteristic white latex is typical of plants in the Apocynaceae family.

Where You’ll Find It Growing Wild

San Lorenzo milkvine is exclusively native to Puerto Rico, making it a true island endemic. This means if you’re growing it anywhere else in the world, you’re essentially serving as a botanical ambassador for Puerto Rican flora.

Should You Grow San Lorenzo Milkvine?

Here’s where things get a bit tricky – and honestly quite intriguing. San Lorenzo milkvine is one of those mysterious native plants that hasn’t received much attention from gardeners or researchers. While we know it exists and where it comes from, detailed information about its appearance, growth habits, and cultivation requirements remains limited.

This rarity in cultivation makes it both challenging and potentially rewarding for the adventurous gardener who wants to grow something truly unique.

Growing Conditions and Care

Based on what we know about related milkvine species and Puerto Rico’s climate, San Lorenzo milkvine likely thrives in:

  • USDA hardiness zones 10-11 (essentially tropical and subtropical climates)
  • Well-draining soils that don’t stay waterlogged
  • Areas with some humidity, typical of Puerto Rico’s climate
  • Locations with partial shade to full sun exposure

As a perennial herb, you can expect it to return year after year once established, though it may die back during cooler or drier periods.

The Reality of Growing Rare Natives

Let’s be honest – San Lorenzo milkvine isn’t going to be the star of your landscape design. As a forb herb, it’s more likely to play a supporting role, contributing to biodiversity rather than commanding attention with showy blooms or dramatic foliage.

If you’re specifically interested in this plant, you’ll need to source it responsibly. Since detailed information about its conservation status isn’t readily available, it’s crucial to work with reputable native plant nurseries or botanical institutions if you want to add it to your garden.

A Plant for the Truly Dedicated

San Lorenzo milkvine represents the kind of plant that appeals to serious native plant enthusiasts – those who value ecological authenticity over instant gratification. If you’re someone who gets excited about preserving Puerto Rico’s unique botanical heritage and doesn’t mind a bit of gardening mystery, this could be the plant for you.

Just remember that with rare natives like this one, patience and research are your best friends. You might need to do some detective work to find reliable sources and growing information, but that’s all part of the adventure of growing something truly special.

San Lorenzo Milkvine

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

Asclepiadaceae Borkh. - Milkweed family

Genus

Matelea Aubl. - milkvine

Species

Matelea borinquensis Alain - San Lorenzo milkvine

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