North America Native Plant

Kamanomano

Botanical name: Cenchrus agrimonioides var. agrimonioides

USDA symbol: CEAGA

Life cycle: perennial

Habit: grass

Native status: Native to Hawaii  

Kamanomano: Hawaii’s Rare Native Grass Worth Protecting Meet kamanomano (Cenchrus agrimonioides var. agrimonioides), one of Hawaii’s most precious and endangered native grasses. This little-known perennial grass holds a special place in Hawaiian ecosystems, but its rarity makes it both fascinating and concerning for native plant enthusiasts. A True Hawaiian Native ...

Rare plant alert!

Region: Conservation status by state

Status: S1T1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Kamanomano: Hawaii’s Rare Native Grass Worth Protecting

Meet kamanomano (Cenchrus agrimonioides var. agrimonioides), one of Hawaii’s most precious and endangered native grasses. This little-known perennial grass holds a special place in Hawaiian ecosystems, but its rarity makes it both fascinating and concerning for native plant enthusiasts.

A True Hawaiian Native

Kamanomano is exclusively native to Hawaii, making it a true endemic species found nowhere else on Earth. This perennial grass represents part of Hawaii’s unique botanical heritage that evolved in isolation over millions of years. As a grass-like plant, it belongs to the diverse family of graminoid species that once dominated many of Hawaii’s natural landscapes.

Currently, kamanomano is found only in Hawaii, where it clings to existence in increasingly limited habitats.

Why This Grass Matters (And Why You Should Be Cautious)

Here’s the important part: kamanomano carries a Global Conservation Status of S1T1, which indicates it’s critically imperiled. This means the species is at extremely high risk of extinction, with very few populations remaining in the wild.

If you’re considering growing kamanomano, please note:

  • Only obtain plants or seeds from reputable native plant nurseries
  • Ensure any material is ethically and legally sourced
  • Never collect from wild populations
  • Consider this plant only if you’re committed to conservation efforts

Garden Role and Landscape Use

Due to its extreme rarity, there’s limited information about kamanomano’s specific garden performance. However, as a native Hawaiian perennial grass, it would likely be most appropriate for:

  • Native Hawaiian plant gardens
  • Conservation-focused landscapes
  • Educational or botanical garden settings
  • Restoration projects (with proper permits and guidance)

Growing Conditions and Care

Specific cultivation information for kamanomano is scarce due to its rarity. As a Hawaiian native grass, it likely thrives in:

  • USDA hardiness zones 10-12 (tropical conditions)
  • Well-draining soils typical of Hawaiian environments
  • Conditions similar to its native habitat requirements

Because detailed growing information is limited, anyone attempting to cultivate this species should consult with Hawaiian native plant experts or botanical institutions.

A Plant for Conservation, Not Casual Gardening

Kamanomano isn’t your typical garden grass recommendation. Its critically imperiled status means this plant is more suited for serious conservation efforts than casual landscaping. If you’re passionate about Hawaiian native plants and committed to conservation, this species represents an opportunity to participate in preserving Hawaii’s botanical heritage.

For most gardeners interested in native Hawaiian grasses, consider working with local native plant societies to find more common native alternatives that can provide similar ecological benefits without the conservation concerns.

The Bottom Line

Kamanomano stands as a reminder of what we stand to lose when native ecosystems face pressure. While it may not be the right choice for most home gardens, its story highlights the importance of protecting and preserving Hawaii’s unique native plant communities. If you do choose to grow this rare grass, make sure you’re doing so as part of broader conservation efforts and always source responsibly.

Kamanomano

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Cenchrus L. - sandbur

Species

Cenchrus agrimonioides Trin. - kamanomano

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