Psydrax odorata
Rubiaceae or Coffee family
Synonyms: Canthium lucidum, Canthium odoratum, Coffea odorata, Plectronia kohenua var. kohenua, Plectronia kohenua var. latifolia, Plectronia marquesensis var. acuta, Plectronia marquesensis var. marquesensis, Plectronia odorata
Alaheʻe
ʻŌheʻe, Walaheʻe
Lamboto, Shiny-leaved canthium
Natural Range & Environment
Psydrax odorata is indigenous to the Society, Marquesas, and Hawaiian Islands, Micronesia, and the South Pacific from the New Hebrides and New Caledonia east to the Tuamotu Islands. In the Hawaiian Islands, it grows wild on all the main islands except Ni‘ihau and Kaho‘olawe [Flora of the Hawaiian Islands]. In Hawai‘i, alahe‘e is found in dry shrublands and dry to mesic forests, and apparently in wet forest on Mount Ka‘ala, O‘ahu, from 10 to 860[-1,160] m (33 to 2,822[-3,806] ft) [Wagner et al. 1990].
Alahe‘e flowers collectively produce a sweet citrusy fragrance that one can smell a considerable distance from the tree. Closeup of ripe black fruits (Note moth larvae damage [holes] to the two fruits on the left). Cultivated shrub-like alahe‘e in bloom. Alahe‘e hedge (Photograph courtesy of Greg Koob ©). Two cultivated alahe‘e trees.
Description
Psydrax odorata, with a lifespan well beyond five years, has smooth pale-gray bark and hard durable off-white wood. Hawai‘i populations differ little in leaf, flower, or fruit morphology, but considerably in stature and shape. For example, near Akaluaiki in West Maui, there is a stand of dwarf alahe‘e that are only about three feet (1 m) tall. And, on O‘ahu, you can find shrubby mature alahe‘e about six feet (2 m) tall growing in open shrubland, while much taller trees (30 ft; 10 m) can be seen in closed dry forests. Some of this variation is undoubtedly the result of the plant's environment, but some too is very likely genetically based (and, we'll just have to wait for the proper scientific study to tell us how much). Therefore, if you buy your alahe‘e, be sure to ask the grower what the parent plant looks like so you can avoid trying to grow a shade tree from the seedling of a shrubby parent alahe‘e.
The elliptical leaves of alahe‘e are one to two inches (2.5 to 5 cm) long, arranged in opposites along their stems, and have a glossy upper surface and dull lower surface; the leaves remain shiny even during periods of drought. In Hawai‘i, it's easy to confuse the commonly cultivated alien mock orange (Murraya panculata) with the less commonly cultivated alahe‘e since both have similar-looking leaves, bark, and flowers. In fact, this similarity is why locals sometimes refer to mock orange as alaheʻe haole (foreign alahe‘e). However, while visually similar, the two plants are actually unrelated to each other, with alaheʻe being a member of the Coffee family (Rubiaceae) while Murraya panculata belongs to the Rue or citrus family (Rutaceae). If you find yourself in doubt about what you are looking at, alahe‘e or mock orange, there is a way to tell the difference by looking closely at the leaves (see photographs and caption below); there are also differences between the flowers (or fruits) but these are not always present.
Psydrax odorata produces clusters of small fragrant (see Hawaiian Name below) perfect (bisexual) white flowers once a year, usually during the spring; cultivated trees may have an extended flowering and fruiting season. En masse, the blooms can light up a dark green alahe‘e like a Christmas tree. Pollinated flowers develop into small round green fruits that soften and turn dark purple to black when ripe. Inside each fruit are two (sometimes one) wrinkled half-moon-shaped brown seeds.
Alahe‘e (Psydrax odorata) leaves (left) compared to a mock orange (Murraya panculata) compound leaf with leaflets (right). Don't be distracted by color differences, which can vary in both species. Rather, note the tiny bud at the tip of the alahe‘e stem, absent from the mock orange leaf, and the opposite arrangement of the leaves in alahe‘e versus the alternate arrangement of leaflets in mock orange. (Photograph of alahe‘e leaves courtesy of airish11 CC BY-NC 4.0; photograph of mock orange leaf courtesy of 東山國小50115施詠嵐 CC BY-NC 4.0.)
Growth Requirements
General
Psydrax odorata is a versatile plant in the landscape. Depending on the variety (see Description above) and how much you are willing to prune, alahe‘e can be used as an accent or screen (little to no pruning), shade tree (some pruning), or hedge (regular pruning). Alahe‘e can also be kept in a container. For screens and hedges, space your alahe‘e three to six feet (1 to 2 m) apart. If your plan is to create shade, consider planting a cluster of three to five alahe‘e spaced about ten feet (3 m) apart from each other, since a single tree will not produce a lot of shade. Also, as the trees grow, begin removing the trees' lower branches and gradually prune your way up in order to create an open shaded ground space beneath the trees.
Alahe‘e has wide temperature (equal to altitude here in Hawai‘i), light, and soil moisture tolerances. It will survive outside a hot beach house all the way up to a cool mountain retreat. And, while alahe‘e grows and flowers best in a site with full sunlight for all or most of the day, it can also grow in shade. However, alahe‘e planted in a deeply shaded site will be spindly, have fewer leaves, and may not flower. Alahe‘e is extremely drought tolerant but can also grow in areas with consistently moist (even wet) soil — provided that soil drains water well. Alahe‘e is not picky about soil type, and will grow in lava/cinder, clay, or organic-dominant soil, again, provided the soil drains well; a friend even got one to grow in the sandy soil outside his home.
When first placed in the ground, water your young alahe‘e regularly (i.e., about once a week) until it's established and starts putting out new stems and leaves. Then, cut back on your watering. In very dry locations, watering once or twice a month is normally best; in wetter locations, anywhere from once every couple of months to not at all will keep your alahe‘e "happy." Alahe‘e prefers long deep waterings rather than short showers, with the surface soil being dry most of the time. And, fortunately, alahe‘e is good at telling you if it needs more water as its leaves will begin to wilt or fall off before the plant dies.
Initially, newly-planted alahe‘e grow quite slowly, even when fertilized and watered. However, after about a year in the ground, your young tree should start growing at the rate of one to two feet (30 to 60 cm) per year. Flowers and fruits normally develop after reaching about three feet (1 m) tall. If you are impatient, you can often find a nursery that will sell you a good-sized (e.g. 3 to 4 ft) alahe‘e.
Generally, alahe‘e in the ground do not need much, if any, fertilizer. However, if you observe very slow growth or yellowing leaves, try applying either a balanced controlled-release fertilizer with minor elements every six months, or spraying the leaves monthly with a water-soluble foliar fertilizer diluted to ⅓ to ½ the recommended strength.
Pests and Diseases
Serious pests can be the coffee green scale (Coccus viridis), black twig borer, and root mealybugs; regularly check the base of your alaheʻe for these mealybugs. For each of the above pests, refer to the Pests & Diseases page for treatments.
If you plan to collect seeds, look for holes in the fruits (see photograph above). These are caused by the larvae of a native moth (Orneodes objurgatella) that feed on alahe‘e seeds. If the damage from this seed predator is extreme, consider bagging or repeatedly spraying the small immature fruits with a systemic insecticide.
Uses
Ancient Hawaiian
While kauila (Alphitonia ponderosa and Colubrina oppositifolia) and uhiuhi (Mezoneuron kavaiense) were preferred, Hawaiians often fashioned the hard wood of the more common alahe‘e into tools and fishing implements such as ʻōʻō (digging stick), composite shark hooks (makau manō), and fishing spears. (What could be better than a spear made of alahe‘e for he‘e spearfishing!) [Krauss 1993]. Alahe‘e wood was also fashioned into a type of adze to carve softer woods, such as wiliwili [Malo 1903].
A black kapa dye was made from alahe‘e leaves [Krauss 1993]. According to Ka‘aiakamanu (1998), walahe‘e was used to "cure heart illness" and "cleanse the blood."
While we could not find any reliable written records of ancient Hawaiians using the fragrant flowers of alahe‘e, it seems at least possible they found some use for them, maybe for adornment.
Modern
Special Features and Information
General
The large Coffee family (Rubiaceae) has about 14,100 species in about 580 genera with the most species diversity found in the tropics or subtropics. [WikipediA;Rubiaceae].
Hawaiian Name
We have heard different interpretations for the meaning of the name alahe‘e, but the one we prefer is from Heidi Bornhorst (2005). According to Heidi, the ala in alahe‘e is a corruption of ‘ala, which means "fragrance," while he‘e is the Hawaiian word for octopus. So, does this mean alahe‘e smells like an octopus? No. Rather, the fragrance of alahe‘e flowers is slippery — like an octopus. Long ago, Hawaiians discovered the best way to appreciate the fragrance of alahe‘e flowers was not to pick the flowers and bring them to your nose, but rather to stand downwind and let the scent come to and envelop you.
Etymology
The genus name, Psydrax, is from the Greek word, psydrax, for "blister or bump," possibly referring to the bumps on the upper leaf surface above the domatia or, alternatively, to the warty seeds of some species [Flora of Caprivia;Psydrax]. The species name, odorata, is the feminine form of the Latin word odoratus, meaning "sweet or pleasant fragrant," referring to the sweet-smelling flowers [Gledhill 2008].
BPK