Bolboschoenus maritimus

leaf Main Plant Information

Genus

Bolboschoenus

Species

maritimus

Hawaiian Names with Diacritics

  • Kaluhā
  • Makai

Hawaiian Names

  • Kaluha
  • Makai

Common Names

  • Bulrush
  • Makai sedge
  • Saltmarsh bulrush

Synonyms

  • Schoenoplectus maritimus

leaf Plant Characteristics

Distribution Status

Indigenous

Endangered Species Status

No Status

Plant Form / Growth Habit

  • Non-Woody, Clumping

Mature Size, Height (in feet)

  • Grass-like, Tall, Greater than or equal to 2.5

Mature Size, Width

Each plant spreads by rhizomes out to two or more feet into an indistinguishable mass of vegetation.

Life Span

Short lived (Less than 5 years)

Landscape Uses

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

Additional Landscape Use Information

Kaluhā grows with a soil pH of 6.0-9.0 in fine clay, silty loam, or sand and is tolerant of alkaline and saline soils. The roots form a thick interwoven mass that helps with soil erosion in wetlands sites and filters waste products from the water. [1]

This sedge is an excellent for reconstructing natural Hawaiian wetlands and provides a food source and shelter for native waterfowl. [1]

Kaluhā naturally grows with other sedges such as makaloa (Cyperus laevigatus) and can be used likewise in water features in the landscape. [David Eickhoff, Native Plants Hawaiʻi]

Source of Fragrance

  • No Fragrance

Plant Produces Flowers

Yes

leaf Flower Characteristics

Flower Type

Not Showy

Flower Colors

  • Brownish

Additional Flower Color Information

Plants have from three to numerous pale brown flower spikelets.

Blooming Period

  • Year Round
  • Sporadic

Additional Blooming Period and Fruiting Information

In Hawaiʻi, after kaluhā sending up foliage, flowers and setting fruits, it then dies back partially or completely year round, unlike those in the continental USA which die back during winter months.

Kaluhā will reseed on site.

The seeds can also be gathered and stored in the refrigerator for future sowing. Use caution when harvesting seeds as they have small hairs that irritate the skin, inducing a rash-like sensation and appearance. [David Eickhoff, Native Plants Hawaiʻi]

leaf Leaf Characteristics

Plant texture

  • Coarse

Additional Plant Texture Information

Kaluha leaves range from one to 5 feet in length.

Leaf Colors

  • Light Green
  • Medium Green

leaf Pests and Diseases

Additional Pest & Disease Information

Kaluhā can attract ants, scale, thrips, mealy bugs and aphids.

leaf Growth Requirements

Fertilizer

If planted in containers that hold water, some fertilizer are appreciated. But be cautious of too much nitrogen, which will likely produce excessive nitrogen levels to greatly increase green algae content in water, especially during the summer months.

No fertilizers are necessary in large water features such as fish ponds because the plants will receive their nutrient needs from the watery habitat.

Never apply fertilizer to any natural wetlands sites. [David Eickhoff, Native Plants Hawaiʻi]

Pruning Information

Prune dead foliage and spent seed stalks as needed or allow seeds to drop into water for natural reseeding.

Water Requirements

  • Moist
  • Wet

Additional Water Information

Kaluhā grows naturally in and at the edge of water features such as ponds, lakes, shorelines, and estuaries in fresh, brackish and saline water. This hardy sedge can tolerate extremes, from being completely submerged in water to periods of drought. During droughts they will die back to the ground into a dormancy. In the landscape it is therefore recommended to keep the plants moist to very wet at all times so as not to initiate dormancy.

Soil must be well drained

No

Light Conditions

  • Full sun
  • Partial sun

Additional Lighting Information

This sedge performs best in full sun but will tolerate some shade.

Spacing Information

Kaluhā has a spreading rhizome root structure, so plant them at least one foot apart.

Tolerances

  • Waterlogged Soil
  • Drought
  • Brackish Water
  • Wind
  • Salt Spray

Soils

  • Clay
  • Sand
  • Organic

Limitations

Kaluhā are naturally perennial but sometimes perform more like annuals. Though the plants can survive occasional periods of drought, they will die back if the ground dries out, but will appear with the next rain or flooding.

Use caution if collecting seeds as the seed heads have tiny prickles that lodge in the skin, acting as an irritation. The prickles can be removed with good lighting and tweezers. [David Eickhoff, Native Plants Hawaiʻi]

leaf Environmental Information

Natural Range

  • Niʻihau
  • Kauaʻi
  • Oʻahu
  • Molokaʻi
  • Maui
  • Hawaiʻi

Natural Zones (Elevation in feet, Rainfall in inches)

  • Less than 150, 0 to 50 (Dry)
  • Less than 150, 50 to 100 (Mesic)
  • Less than 150, Greater than 100 (Wet)

Habitat

  • Aquatic
  • Terrestrial

Additional Habitat Information

Kaluhā occur in moist to very wet coastal sites, in fresh or brackish water up to 3 feet deep.

leaf Special Features and Information

General Information

The native sedges comprise nearly sixty native species, many of which are endemic, in the Sedge family (Cyperaceae).

Etymology

Bolboschoenus is from the Greek bolbos, swelling or bulb, and schoinos, rush in reference to the ligneous (woody) tubers at the culm (aerial part of the plant) bases.

The specific epithet martinus, growing by the sea, is in reference to its brackish-freshwater habitat.

The former subspecies name, paludosus, marshy or swampy, refers to the type of habit these rushes are found in.

Background Information

 

Early Hawaiian Use

This indigenous sedge is not known to be used by early settlers in the Hawaiian Islands.

However, in other parts of the world the seeds were used as a food source [1] and the leaves were used in making baskets [2], mats, sandals, and clothing. [1]

Additional References

[1] http://www.plantzafrica.com/plantab/bolbomari.htm [Accessed 10/7/09]

[2] http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357004 [Accessed 10/7/09]

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