Pāpala kēpau (Ceodes brunoniana; formerly Pisonia brunoniana) — Origin of a Name?


    Until recently, I never thought too much about the Hawaiian name of this species (or the other four closely related species with the same Hawaiian name). I just assumed early Hawaiians thought that pāpala kēpau looked similar to another native species group, Charpentiera (also with five native species) called pāpala, except for their very sticky fruits (Charpentiera do not have sticky fruits), hence the adjective kēpau which translates as gum, pitch, tar, resin, or lead. But now, I am wondering how the name pāpala kēpau came to be.

    You see, unlike the five pāpala species which are all endemic, three of the five pāpala kēpau species are indigenous, including Ceodes brunoniana as well as the more widespread Pisonia grandis. Why then didn't early Hawaiians recognize these species and use the presumably older indigenous names, parapara from New Zealand for C. brunoniana or pu‘atea from Tahiti for P. grandis? Perhaps they did since all three names start with a "p". Did language evolution transform parapara (or pu‘atea) into pāpala?

    Unfortunately, I am out of my depth here and have exhausted my research attempts via Google. I was educated and trained as a biologist, not a linguist. However, I am hoping there is someone reading this who is a linguist, and is curious enough to research the origins of the names of our many native plants, particularly the indigenous species which undoubtedly have/had names in places outside of Hawai‘i. (Please, if you do, contact me at koebele@nativehawaiiangarden.org, and let me know what you discover. I would love to amend this introduction.)

Habitat & Appearance: A large shrub or small tree, native to Kermadec, Norfork, and Lord Howe islands, Australia, New Zealand, and the Hawaiian Islands. In Hawai‘i, Ceodes brunoniana grows in mostly mesic areas, but can also be found less often in dry and wet sites, on O‘ahu, Moloka‘i, Lāna‘i, Maui, and Hawai‘i.

    Pāpala kēpau wood is soft and brittle, and the bark is light gray. Leaves are elliptical to ovate, a few to several inches long, and often glossy. Unlike the other four species of pāpala kēpau, C. brunoniana (usually) has perfect (i.e., bisexual) flowers. These are small, clustered on a semi-open cyme, white or greenish, and sometimes tinted red or purple. Fruits are about an inch long, longitudinally ribbed, turning from green to black when ripe, and covered with an extremely sticky resin. Each fruit contains one elongate seed.

(Top to Bottom) Ripe and unripe fruits (photograph courtesy of Kahuroa ©). Sticky fruit (photograph courtesy of G.D. Carr ©). Seedlings. Mature tree (photograph courtesy of Karl Magnacca ©; some rights reserved). (Header photograph of flowers courtesy of G.D. Carr ©.)

Pāpala kēpau in Hawaiian Culture: Kia Manu (Hawaiian bird catchers) used the sticky fruits of pāpala kēpau, smeared onto branches of non-pāpala kēpau trees, to catch native birds for their feathers which were then fashioned into 'ahu'ula [cloaks], mahiole [war helmets], kāhili [standards] and lei. Birds such as 'ō'ō and mamo were plucked of their few yellow feathers and set free to grow more for the next season. However, not all native birds were as lucky. ʻIʻiwi, ʻamakihi and ʻapapane were often plucked of all their red or green feathers and then eaten.

   The milky sap of pāpala kēpau was used for cuts, and the leaves were cooked and used to cure pāʻaoʻao (a childhood disease) and for lepo paʻa (constipation). Hawaiians also used the adhesive gum for repairing bowls.

Collecting Seeds: On O‘ahu, pāpala kēpau fruits ripen during the fall, turning from green to very dark brown or black and becoming very sticky. Collect them directly from the plant or from the ground beneath. (I have often found an entire inflorescence with many ripe fruits on the ground directly beneath a tree.) Fruits from the ground, and even those still on the plant, are usually covered with dirt and dead or dying insects like ants. Back at home, wash them in soapy water as best you can. Or, carefully remove each seed from its fruit, and instead very gently wash the extracted seeds.        

Growing from Seed: Perhaps because they don't want to handle the sticky fruits, some native Hawaiian plant horticulturists simply sow the entire pāpala kēpau fruit in propagation media. This works, but in my experience, germination is faster and more reliable if you first remove the seeds from their fruits. Do this by using your fingernail or a blade to cut through the fruit at one end — being careful not to damage the seed within which is only protected by a thin paper-like seedcoat. You can then peel away the fruit in strips, like peeling a ripe banana, to expose and extract the elongate seed. Gently rinse or wash the seeds, and immediately sow them horizontally in moist media to prevent them from drying out. (While rinsing, you will notice that any non-viable seeds will float and should be discarded.) I normally sow pāpala kēpau seeds using either Method One or Two. However, if you choose Method One, quickly transplant the seedlings to deeper individual pots before they produce their first true leaves because they rapidly develop a deep taproot. With both Methods, sprouting takes 1-2 weeks.

    I have never tried to store pāpala kēpau seeds for more than a few weeks. However, based on a 2019 study conducted by Chau et al. (Seed freeze sensitivity and ex situ longevity of 295 species in the native Hawaiian flora), it looks like the seeds remain viable for less than a year in storage.

    For 1-3 weeks, seedlings, with their two large cotyledons, appear to grow little (although I suspect they are busy elongating their taproots). They then start to develop their first true leaves and begin growing about 1-2 inches taller each month. During this time, they are sometimes attacked by sap-sucking insects such as aphids, mealybugs, and scale insects. Refer to Enemies in the Garden for ways to combat these pests. You should also be watchful for snails and slugs that can consume an entire seedling in one night. Use copper barriers, traps, or baits if these molluscs become a problem.   

Growing from Cuttings: I have never tried to root pāpala kēpau cuttings, but I am told it's not too difficult. Kerin Lilleeng-Rosenberger (2005) recommends: (1) collecting semi-hard to hardwood cuttings, (2) using rooting powder, and (3) placing the cuttings in perlite or black cinder under a misting system. They should then root in about 2-3 months. 

Growth in the Garden: I have seen pāpala kēpau in dry forests. However, these trees were always at or near the bottom of a gulch, suggesting that pāpala kēpau, unlike many other dry forest trees like alahe‘e, kauila and lama, are not very drought tolerant. With this in mind, I have always planted my pāpala kēpau in a shaded site, and have never let the surface soil completely dry out, in contrast to something I often do for many other dry forest plants.

    Ceodes brunoniana is the smallest of Hawai‘i's pāpala kēpau (up to 53 feet tall, but I have never seen one more than 20), and doesn't grow very fast — about one to two feet per year. It can, however, start flowering and fruiting when it is still quite young and small. (One of my plants started flowering when it was only three years old!)  

Diseases & Pests: When small, pāpala kēpau are vulnerable to snails and slugs, so remain wary. Occasionally, I have seen both small and large pāpala kēpau infested by scale insects, almost always with a colony of ants protecting them from predators. The infestation was never life-threatening and sometimes disappeared without treatment. Other times, I have intervened by eliminating the scale insects or the ants (refer to Enemies in the Garden for treatments). 

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