North America Non-native Plant

Calycose Mille Graines

Botanical name: Oldenlandia lancifolia

USDA symbol: OLLA2

Life cycle: annual

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Pacific Basin excluding Hawaii âš˜ Non-native, reproduces and persists in the wild in Puerto Rico  

Synonyms: Hedyotis commutata Schult. & Schult. f. (HECO29)  âš˜  Hedyotis lancifolia Schumach. (HELA17)   

Calycose Mille Graines: A Delicate Tropical Ground Cover Looking for a fine-textured ground cover for your tropical garden? Meet calycose mille graines (Oldenlandia lancifolia), a dainty annual herb that brings subtle charm to warm-climate landscapes. This petite plant might not be the showstopper of your garden, but it has its ...

Rare plant alert!

Region: Conservation status by state

Status: S2?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Calycose Mille Graines: A Delicate Tropical Ground Cover

Looking for a fine-textured ground cover for your tropical garden? Meet calycose mille graines (Oldenlandia lancifolia), a dainty annual herb that brings subtle charm to warm-climate landscapes. This petite plant might not be the showstopper of your garden, but it has its own quiet appeal for those who appreciate delicate textures and naturalized plantings.

What is Calycose Mille Graines?

Calycose mille graines is a small annual forb – basically a soft-stemmed plant that completes its entire life cycle in one growing season. Originally from tropical regions of Africa and Asia, this plant has found its way to various Pacific islands and territories. You might also see it listed under its synonyms Hedyotis commutata or Hedyotis lancifolia in older gardening references.

Where Does It Grow?

Currently, you’ll find calycose mille graines established in Guam, Palau, and Puerto Rico, where it reproduces on its own in the wild. As a non-native species in these locations, it has adapted well to tropical and subtropical conditions.

Garden Appeal and Design Role

This isn’t a plant that will stop traffic, but calycose mille graines offers:

  • Delicate white flowers that add subtle texture
  • Fine, lance-shaped foliage that creates a soft groundcover effect
  • Low-growing habit perfect for filling in naturalized areas
  • Self-seeding capability for effortless coverage

It works well in informal garden settings, naturalized landscapes, and areas where you want a soft, meadow-like appearance without high maintenance.

Growing Conditions and Care

Calycose mille graines is surprisingly easy-going once you understand its preferences:

Climate Requirements: This plant thrives only in USDA hardiness zones 10-12, making it suitable exclusively for tropical and subtropical regions. If you’re in a cooler climate, this one isn’t for you.

Light and Soil: Provide full sun to partial shade and well-draining soil. Like many tropical plants, it doesn’t appreciate waterlogged conditions but needs consistent moisture during the growing season.

Maintenance: As an annual, it will complete its life cycle in one year, but don’t worry – it readily self-seeds in favorable conditions. Simply allow some flowers to go to seed if you want it to return next year.

Pollinator and Wildlife Benefits

The small white flowers attract tiny pollinators like small bees and flies. While not a major pollinator magnet, every little bit helps in creating a diverse ecosystem in your garden.

Should You Plant It?

Here’s where things get a bit complicated. Calycose mille graines has a conservation status of S2?, which indicates some uncertainty about its population status. Additionally, as a non-native species, it’s worth considering whether it’s the best choice for your garden.

If you’re interested in growing it: Source plants or seeds responsibly from reputable suppliers, and be mindful of its self-seeding nature.

Consider native alternatives instead: Before choosing calycose mille graines, explore native ground covers in your area. Native plants typically provide better support for local wildlife and are better adapted to your specific climate conditions.

The Bottom Line

Calycose mille graines can be a charming addition to tropical gardens for gardeners who appreciate subtle beauty and low-maintenance plants. However, given its non-native status and uncertain conservation status, consider it carefully. If you do choose to grow it, source it responsibly and maybe dedicate some space to native alternatives too – your local pollinators and wildlife will thank you for the variety!

Remember, the best gardens often combine different types of plants thoughtfully, creating spaces that are both beautiful and ecologically beneficial.

Calycose Mille Graines

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

Rubiales

Family

Rubiaceae Juss. - Madder family

Genus

Oldenlandia L. - oldenlandia

Species

Oldenlandia lancifolia (Schumach.) DC. - calycose mille graines

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