POSTED: 1:30 a.m. HST, Dec 13, 2010
The whimsical and primeval appearance of alula (Brighamia insignis) makes it one of my favorite endemic Hawaiian plants. Other Hawaiian names include olulu, pua ala, haha, ohaha and pu aupaka.
Alula belongs to the family of Campanulaceae. It's named in honor of William Tufts Brigham (1841-1926), the first director of the Princess Bernice Pauahi Bishop Museum. Brigham, a geologist and botanist, gathered copious collections of native Hawaiian plants, including the initial scientific description of alula. The Latin "insignis" aptly means "remarkable" or "distinguished."
The succulent, stout, usually unbranched stem of alula is about 3 to 6 feet but can rise up to 15 feet. The base of alula is bulbous. Fleshy, shiny to dark-green leaves create a compact rosette at the end of the stem. Leaves are wider at the tip. Softly perfumed tubular flowers in cream to yellow erupt in clusters of three to eight. The tiny green fruit capsules produce pale, oval-shaped seeds.
The shape of alula gives it the unflattering nicknames of "cabbage on a stick" or "cabbage on a baseball bat." I picture alula as a "green lotus on a stalk," which is more consistent with its Latin description.
Habitat for alula ranged from arid, coastal grasslands and shrublands to rocky embankments with minimal soil to precipitous sea cliffs on the Na Pali coast of Kauai. Alula tolerated drought because of its stem's water-storage capabilities and by growing smaller leaves. Horizontal roots enable alula to secure a foundation in the meager soil of crevasses in sloped terrain.
In 1994 alula was listed for protection under the Endangered Species Act. Aggressive, invasive plant species, feral animals (especially goats), landslides, fires, hurricanes and removal by humans have all contributed to the decimation of alula. The introduced carmine spider mite (Tetranychus cinnabarinus) inflicts leaf destruction. The presumed loss of a historic insect pollinator, a hawk (sphingid) moth, was a devastating blow.
Alula populations on Haupu Ridge on Kauai — devastated by the combined ravages of Hurricanes Iwa and Iniki — and in the headlands of Hoolulu and Waiahuakua valleys along the Na Pali shores are now gone. Another alula grouping on Kaali Cliff on Niihau has not been sighted since 1947. With the death of these alula communities, genetic variation is diminished, leading to shrinking reproductive vitality and declining adaptation to evolving environmental factors. Extinction is a precarious reality.
Prevailing research indicates there might be only a solitary alula surviving in the wild on Kauai.
Regeneration of alula is a direct result of laborious hand pollination and seed collection by botanists and horticulturists, later propagating alula in specialized greenhouse facilities. The state Division of Forestry and Wildlife has outplanted alula into the Kalepa and Nounou forest reserves on Kauai. Through seed distribution from Hawaii, alula is now also thriving in botanical gardens around the world.
Culturally, ancient Hawaiians consumed raw portions of alula to treat consumption (tuberculosis) and other ailments. Pulverized leaves were infused with sea salt and applied to cuts and infections.
Alula delivers a sensational visual when landscaped into a xeriscape or rock garden. Its riveting structure makes it superb as a potted plant.
Overwatering is the ruination of alula. In the words of Kerin E. Lilleeng-Rosenberger, from her landmark book, "Growing Hawai'i's Native Plants": "Treat the alula like a succulent; giving it partial sun, a well-aerated soil mix, a little water, and lots of tender loving care."
Duane Choy is a native Hawaiian plant specialist. Reach him at HanaHou@ecologyfund.net.