Cyperus trachysanthos

leaf Main Plant Information





Hawaiian Names with Diacritics

  • Kaʻa
  • Puʻukaʻa (Niʻihau)

Hawaiian Names

  • Kaa
  • Puukaa (Niihau)

Common Names

  • Sticky flatsedge
  • Sticky galingale


  • Cyperus trachysanthus

Names with Unknown Sources

  • Puʻu kaʻa

leaf Plant Characteristics

Distribution Status


Endangered Species Status

Federally Listed

Plant Form / Growth Habit

  • Non-Woody, Clumping

Mature Size, Height (in feet)

  • Grass-like, Medium, 1 to 2.5

Mature Size, Width

Puʻukaʻa has a spread up to 12 inches.

Life Span

Long lived (Greater than 5 years)

Landscape Uses

  • Accent
  • Container
  • Ground Cover
  • Specimen Plant
  • Water Features

Additional Landscape Use Information

Puʻukaʻa can be used as a specimen plant or en masse. This handsome native sedge is an excellent alternative choice for the non-native and greatly over used umbrella sedge (Cyperus alternifolius).

Puʻukaʻa is non-invasive and a beautiful addition to Japanese-style gardens, especially when surrounded by river rock or black cinder.

Plant Produces Flowers


leaf Flower Characteristics

Flower Type

Not Showy

Flower Colors

  • Brownish
  • Yellow

Additional Flower Color Information

Puʻukaʻa has 8 to 20 pale yellowish-brown to pale reddish-brown flowers. [1]

Blooming Period

  • Year Round

Additional Blooming Period and Fruiting Information

These rare sedges are perennials.

leaf Leaf Characteristics

Plant texture

  • Coarse

Additional Plant Texture Information

Puʻukaʻa leaves range from 6 to over 18 inches long. Leaves are leathery and covered with a waxy, sticky coating. The degree of stickiness is apparently influenced by the heat; those growing in more sheltered, hotter locations seem stickier than those growing elsewhere. [1] The leaves are remotely toothed and not as sharp as some other native sedges.

Leaf Colors

  • Medium Green

leaf Pests and Diseases

Additional Pest & Disease Information

Puʻukaʻa is prone to ants, scale, mealy bugs, root mealy bugs and aphids.

leaf Growth Requirements


Puʻukaʻa are not heavy feeders. Use well rotted compost or a weak application of soluble or organic fertilizers once a year.

A light foliar feeding with fish or kelp emulsion at one-third to one-fourth the recommended strength monthly or every other month produces good results. [David Eickhoff, Native Plants Hawaiʻi]

Water Requirements

  • Wet

Additional Water Information

Plants can tolerate both moist and wet conditions. Puʻukaʻa can also be planted directly in the water or in areas with periodic flooding. [David Eickhoff, Native Plants Hawaiʻi]

Soil must be well drained


Light Conditions

  • Full sun
  • Partial sun

Additional Lighting Information

Puʻukaʻa can tolerate some shading but will not grow to its full potential.

Spacing Information

Plants should be spaced 12 to 18 inches apart.


  • Waterlogged Soil
  • Drought
  • Salt Spray


  • Clay
  • Sand


Puʻukaʻa does not do well in extremely windy areas because the leaves dry out and make the plant less attractive.

leaf Environmental Information

Natural Range

  • Niʻihau
  • Kauaʻi
  • Oʻahu
  • Molokaʻi
  • Lānaʻi

Natural Zones (Elevation in feet, Rainfall in inches)

  • Less than 150, Greater than 100 (Wet)
  • 150 to 1000, Greater than 100 (Wet)


  • Terrestrial

Additional Habitat Information

Puʻukaʻa is known to grow in wet sites such as margins of ponds, wet slopes, mud flats, or wet clay soil. [2] Plants are found in dry regions in locations that are moist to flooded at least during the winter wet season. [Joel Lau, Botanist]

It is now found only on Kauaʻi, Oʻahu and possibly Niʻihau (Mokouia Valley).

leaf Special Features and Information

General Information

There are fourteen species in the genus Cyperus that are native to the Hawaiian Archipelago, with eight that are endemic, or found exclusively, here. Cyperus belong to the Sedge Family (Cyperaceae) consisting of some 4,000 species in about 70 genera.

Famous, or infamous, non-native relatives include papyrus (Cyperus papyrus), the source of the Egyptian writing material and the origin of the English word paper; piripiri or cañita (Cyperus giganteus) used in parts of Mexico for plaiting sleeping mats and sambreros; and the ever-present noxtious lawn weed nutsedge or "nutgrass" (Cyperus rotundus) that keep homeowners busy and gardeners employed, but also used in Kampō (traditional Japanese/Chinese medicine). [4]


The generic name Cyperus comes from the kyperos, the Greek word for sedge.

The specific epithet trachysanthos is from the Greek trachy, shaggy or rough, and santhos, flowered.

Hawaiian Names:

Puʻukaʻa is a Niʻihau name and the one used most locally. This Hawaiian name is also used for the Fragrant flatsedge (Cyperus odoratus [syn. Torulinium odoratum subsp. auriculatum]), a rare indigenous sedge found in the Hawaiian Islands.

Another seldom used name is Kaʻa. [3]

Background Information

Of the fourteen species of native sedges in the genus Cyperus, puʻukaʻa is certainly one of the rarest and is federally listed as an endangered species.

Early Hawaiian Use

Medicinally, this sedge was "stewed until completely cooked." Then, used in bathing "until the very small and fine lumps (puʻu) fall off." [5]

Modern Use

The attractive flowering spikes can be used in cut flower arrangements [Linda Bard, Waimea Valley].

They can also be used in haku or wiliwili style lei. [Rick Barboza, Hui Kū Maoli Ola]

Additional References

[1] "Flora Hawaiiensis" by Otto Degener, Family 48: Cyperus Trachysanthus
[2] "Recovery Plan for the Muli-Island Plants" by USFWS, pages 67, 68.
[3] "A Chronicle and Flora of Niihau" by Juliet Rice Wichman and Harold St. John, page 68.

[4] [accessed 10/12/09]

[5] "Native Hawaiian Medicine--Volume III" by The Rev. Kaluna M. Kaʻaiakamanu, page 90.



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