I’m puzzled why olena (Curcuma longa) is not more widely cultivated in our Hawaii gardens.

Olena has beautiful leaves, an ethereal flower and underground stems (rhizomes) that deliver exceptional culinary and health benefits. In other areas of the globe, olena is known as turmeric (a major component of curry powder) and belongs to the ginger family.

Olena journeyed to Hawaii as one of the canoe plants brought by the early Polynesian settlers.

The word "olena" also means "yellow" in Hawaiian. The orange rhizomes provided a dynamic yellow dye for kapa bark cloth. Young rhizomes exuded a lustrous yellow, while older rhizomes produced a profound golden-yellow. The comprehensive book "Hawaii Dye Plants and Dye Recipes," by Val Frieling Krohn-Ching, states, "Cut the fresh olena tubers into thin slices and soak overnight in two cups of water. Add 10 more cups of water and boil for one hour. Remove tubers and immerse wet, heated wool in dye bath. Stir for the first few minutes. Simmer for 30 minutes. Cool yarn in dyebath. Rinse, and dry in shade."

There is no true stem above ground for olena. The plant is deciduous. Clustered, stalked leaves emerge in the spring and start browning and disappearing in the fall before entering into winter dormancy. A cylindrical flower spike arises from the center. White to pale-green, pouch-curved bracts exhibit two or more blanched-yellow blossoms, except at the top of the stalk.

Pharmacological analysis has established anti-inflammatory, antioxidant, anticoagulant and anti-cancer properties of olena and its ingredient curcumin.

Early Hawaiians administered olena medicinally for growths in the nostrils, stuffy nose, sinus ailments, earaches and as a blood purifier.

In a Hawaiian cultural purification ritual, rhizomes of olena were infused into salt water, and a kahuna used a frond of limu kala (seaweed) to sprinkle the purifying fluid on people, objects or places.

The Hawaii Agriculture Research Center conducted studies of what specialty crop might thrive as the understory to koa forest farming and concluded, "Olena appears to be an excellent understory crop for koa tree farms owing to its high tolerance for shade. … Harvest of the ornamental bracts for flower arrangements could also serve as another source of income."

Olena thrives in well-nourished, moist soil. Propagation is from the buds on the rhizome nodes, which will sprout into keiki olena.

Olena deserves a more prominent habitat and ornamental focus in our Hawaii landscape.

Duane Choy is a native Hawaiian plant specialist. Reach him at HanaHou@ecologyfund.net.