Family: Cyperaceae

ʻUki is a non-woody clumping sedge with short rhizomes. This large perennial sedge can grow up to 1-4 feet tall and 3 feet wide. Leaves are light green, rigid, and wedge-shaped. They do not have a midrib, can be up to 4 feet in length, and 1 inch wide. ʻUki flowers all year round and on top of that, its flowering parts are long-lasting and showy. Dark brown flowers are arranged in spikelets of 3-6 flowers in a panicle inflorescence that can be over 1.5 feet long. ʻUki will produce yellow-brown achene fruits that have an ellipsoid shape and are slightly winged.

Machaerina angustifolia belongs to the Cyperaceae family, which also includes the endemic Machaerina mariscoides or ‘ahaniu. Though they look very similar, the leaves of the ‘ahaniu have a silvery-gray hue and you can find them at lower elevations (>150 feet) compared to ʻuki (>1000 feet).

Habitat & Uses

ʻUki is commonly found in wet ecosystems across the Main Hawaiian Islands from 1380-6790 feet elevation. Habitat includes wet forests, mid-elevation woodlands, bogs, wet lava and cinder fields. Therefore, ʻuki prefers moist conditions, can tolerate high winds, and enjoys full sun. You will typically find ʻuki growing amongst ʻōhiʻa, uluhe, ʻōlapa, hāpuʻu, and pūkiawe. This indigenous plant can also be found in other areas of the Pacific like Papua New Guinea and the Society Islands. Unfortunately, feral pigs will feed on the leaf bases of ʻuki, which makes this plant harder to find in infested areas.

ʻUki is a wonderful ornamental with other added values. The flowering stalks of ʻuki have bracts that remain on the stalks indefinitely, which makes them perfect for dried floral arrangements.  Their shiny dark stalks and stark flower clusters provide beautiful contrast against the more common green and red plant hues. This makes ʻuki an important cultural plant for lei-making, ritual attire, and hula adornments. Historically in Hawaiʻi, ʻuki leaves were used in lashing for thatching houses, cordage, and temporary mats/bedding. There is also evidence for ʻuki being used for erosion control and as food. The pale white base of its leaves tastes similar to artichoke hearts.

Landscaping

ʻUki is a tall bullrush, which makes an excellent and unique accent plant for landscaping. However, it can be challenging to establish if not provided enough sun and moisture. ʻUki prefers continuously moist soils, so it may not be suited for leeward and low elevation areas. In the right climate and sun, this plant is easy to care for. Some common pests include ants that farm mealybugs, scales, and aphids. This plant is a great substitute for the invasive New Zealand flax, which looks similar to ʻuki except for the indicative orange coloring on the flowering stalk and leaves.

Cultivation

ʻUki is not a commonly cultivated plant in the nursery trade, but it would be a great addition! Machaerina angustifolia is known to be easy to cultivate and propagate. Propagation is best done through division or by seed. Division is best done in the Spring or Fall when the plant is actively growing. To do this, dig up under the clumping sedge to expose underground stems and then cut off a section/clump. Keep the cutting moist and the cut the leaves in half until ready to pot. You should begin to see new foliage in one to two months.

If propagating by seed, sow in a moist well-draining soil mix (3 parts perlite to 1 part potting mix) until germination.  To collect seeds, gather brown dry flowering stalks, let them air dry at room temperature, and remove the seed coating by rubbing fruits together to dislodge seeds. Collected seeds can be stored up to eight years. You can surface sow seeds and allow water to move below the surface. Germination requires watering every other day and you should see the plant emerging anywhere from two weeks to three months. New seedlings can be transplanted into 2-4 inch pots filled with a well-draining soil mix (amend with cinder). Once established, these plants need water only in times of prolonged drought.

Name Origins

The ʻŌlelo Hawaiʻi ʻuki is a word for multiple native sedges including the native ʻukiʻuki, ʻahaniu, and Cladium jamaicense. Machaerina can mean bent dagger or sword, which refers to how its leaves behaves. This is especially evident once leaves get long and bend from the weight. The species name angustifolia means narrow leaved, which refers to its particularly slender and pointy leaves.

Plant Uses:

• Cultural significance
• Cut flower
• Edible
• Erosion control
• Lei flower
• Ornamental

Plant Dangers:

• No dangers