Argyroxiphium grayanum

Common Names

Greensword, Hana Forest Silversword, Silversword

Summary

Greensword, Hana Forest Silversword, is a Maui-endemic perennial shrub in the Asteraceae family that forms an erect, single-stemmed monocarpic rosette up to 2 m tall with green, narrowly elliptic-ligulate leaves that are 5–11-nerved. Native to montane bogs at 1,200–2,050 m elevation, it thrives in high-moisture, low-light, cool environments. The inflorescence is long (1–10 dm) and wide (6–40 cm), bearing 0–10 pale yellow ray florets and 100–300 disk florets, with wind-dispersed fruits (achenes and pappus) and pollination by native Hymenoptera and Diptera.

Conservation status is globally G1 and Hawaii S1, with endangered designation under state law; threats include feral pigs and goats, invasive weeds, habitat loss, and climate-change-driven hydrological shifts. Conservation actions include fencing Greensword Bog, ex situ propagation in greenhouses, outplanting, weed control, and monitoring. Propagation is possible via seeds (mature seeds collected, stored cool/dry) or vegetative methods such as stem cuttings, division, or tissue culture, and the plant is bog-adapted, requiring high moisture, low light, and cool temperatures.

Lifecycle

Perennial (monocarpic in unbranched forms; polycarpic when branched).

Height

less than 12 inches – about 6 ft 7 in

Sunlight Requirements

Ideally partial shade.

Soil Type

Bog soil, very moist, waterlogged, acidic with high organic content

Soil Drainage

Poor drainage

Soil pH

5.5-6.5, Acidic soils.

Bloom Color

Yellow

Bloom Time

Summer

Foliage Color

Green

Fall Foliage Color

Green

Leaf Lifecycle

Evergreen broadleaf

Seasons of Interest

Summer, Fall, Winter

Propagation Methods

Seed propagation, stem cuttings, division, tissue culture

Attracts Wildlife

Bees, Other pollinators (flies, hoverflies), Birds (apapane occasionally visit for nectar)