Mauna Loa (=Ka'u) silversword (Argyroxiphium kauense)

Listing Status: Endangered

Where Listed: WHEREVER FOUND

General Information

Argyroxiphium kauense is a rosette shrub, usually single-stemmed, its vegetative stems about 3 to 70 cm (1 to 24 in) long, and flowering stems about 0.7 to 2.5 m (2 to 8 ft) long. The leaves are very narrowly sword-shaped, 3- to 4-angled in cross section, about 20 to 40 cm (8 to 16 in) long and 0.5 cm (0.2 in) wide at the middle, nearly covered with dense, silky, silvery gray hairs. The flowering stalk as many branches, each with a flowering head of 3 to 11 ray flowers each about 1 cm (0.4 in) long, and 50 to 200 disk flowers each about 0.6 cm (0.2 in) long. The fruits are dry and black.
Current Listing Status Summary

» Range Information

Current Range
Last Updated: 06-17-2021 - Wherever found
Zoom in! Some species' locations may be small and hard to see from a wide perspective. To narrow-in on locations, check the state and county lists (below) and then use the zoom tool.
Want the FWS's current range for all species? Click here to download a zip file containing all individual shapefiles and metadata for all species.
* For consultation needs do not use only this current range map, please use IPaC.

Current range maps are only shown within the jurisdictional boundaries of the United States of America. The species may also occur outside this region.

  • Wherever found

    Listing status: Endangered

    • States/US Territories in which this population is known to or is believed to occur: Hawaii
    • US Counties in which this population is known to or is believed to occur: View All
    • USFWS Refuges in which this population is known to occur: 

» Candidate Information

No Candidate information available for this species.

No Candidate Assessments available for this species.

No Candidate Notice of Review Documents currently available for this species.

No Uplisting Documents currently available for this species.

» Federal Register Documents

Federal Register Documents

» Species Status Assessments (SSAs)

Species Status Assessments (SSAs)

No Species Status Assessments (SSA's) are currently available for this species.

Special Rule Publications

No Special Rule Publications currently available for this species.

» Conservation Plans

Safe Harbor Agreements (SHA): (learn more)

» Petitions

No Petitions currently available for this species.

» Biological Opinions

To see all FWS Issued Biological Opinions please visit the BO Report.

» Life History

Habitat Requirements

Argyroxiphium kauense is endemic to the south slopes of Mauna Loa on the island of Hawaii. It occurs primarily in moist forest openings or bogs at about 1,600 to 2,320 m (5,300 to 7,600 ft) elevation, although plants also occur on well-drained substrates and in relatively dry sites. The substrate is aa or pahoehoe lava, sometimes with wet humus, on flat to steep and irregular ground. The vegetation is most typically dry scrub or scrub forest dominated by the native plant Metrosideros polymorpha (ohia) with such associates as Leptecophylla tameiameiae (pukiawe), Coprosma ernodeoides (alakanene), Dodonaea viscosa (aalii), Geranium cuneatum (nohoanu), and Vaccinium reticulatum (ohelo). The open bog site shares those associates but is dominated by native sedges (Oreobolus furcatus, Rhynchospora chinensis ssp. spiciformis (kuolohia), and Carex montis-eeka).

Reproductive Strategy

The plant increases in rosette diameter and stem height for a number of years, and then produces a single, tall inflorescence (flowering part of plant) with hundreds of capitula (flower heads), each containing up to 200 florets (small flowers that are part of a dense cluster). After fruit set, the entire plant dies (monocarpic). The white or yellow to wine-red flowers bloom in August and September. This species probably reproduces only by seed; there is no evidence of vegetative reproduction. The low seed set found for certain individuals also indicates that this species is at least partially self-incompatible; however, some plants are capable of setting a small quantity of seed by self-fertilization. Fruit dispersal is probably restricted to areas immediately surrounding parent plants. Fruits are shed from September to October. Seeds do not exhibit long-term dormancy and probably germinate in late winter and early spring during periods of high rainfall.

Other

It differs from Argyroxiphium sandwicense ssp. sandwicense and ssp. macrocephalum primarily by having the vegetative rosette of leaves elevated on an erect stem, longer and thinner leaves which are triangular rather than flat in cross-section, somewhat sparser leaf pubescence (hairs) appearing silver-gray rather than silver-white, and fewer ray flowers per head.

» Other Resources

NatureServe Explorer Species Reports-- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports-- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video." +

Loading...