Santalum ellipticum
Santalaceae or Sandalwood family
Synonyms: Santalum album var. ellipticum, Santalum cuneatum, Santalum cuneatum f. gracilius, Santalum cuneatum var. gracilius, Santalum cuneatum var. laysanicum, Santalum ellipticum var. gracilius, Santalum ellipticum var. littorale, Santalum ellipticum f. physophora, Santalum freycinetianum var. cuneatum, Santalum freycinetianum var. ellipticum, Santalum freycinetianum var. littorale, Santalum littorale
ʻIliahialoʻe
‘Aoa, ʻIliahi aloʻe, Lāʻau ʻala
Coast sandalwood, Coastal sandalwood
Natural Range & Environment
Santalum ellipticum is known (i.e., reported) from Laysan (Kauō) and all the main Hawaiian Islands except Ni‘ihau. However, it is now extirpated from Laysan and Kaho‘olawe, and is rare on Kauaʻi. While not recorded from Niʻihau, many botanists think it grew there at one time [Stemmermann 1990]. Wild Santalum ellipticum have been found on ridges, slopes, and in gulches, often on ā‘ā lava or rocky sites, in dry shrublands and forests, often persisting in areas invaded by exotics, from the coastline to 560[-945] m (1,837[-3,100] ft) [Wagner et al. 1990].
The leaves of cultivated plants (top) can sometimes look different (e.g., thinner and darker) from those of wild plants (bottom). A cultivated coastal form of ʻiliahialoʻe and a pruned montane form. Compare these to this larger wild tree in upland Maui. (Photographs of cultivated and wild plants courtesy of Forest & Kim Starr CC BY 3.0 US).
Description
Wild Santalum ellipticum vary dramatically in stature, leaf morphology, and even flower color depending on where they are found. We are still waiting for a common garden experiment to determine how much of this morphological variation is genetically based and how much is the result of different environmental conditions. However, generally, wild ʻiIiahialoʻe very near the ocean are prostrate or sprawling and have blue-green leathery leaves. As you move inland, the ʻiliahialoʻe you see get taller, first being very bushy shrubs, and then eventually becoming undeniable trees in the uplands (see photographs above). ʻIliahialoʻe's leaves also change, becoming less and less leathery, and more and more green and droopy (as they hang from the branches). And, while most ʻiliahialoʻe have greenish- or yellowish-white flowers, there are some places like Nānākuli Valley where some ʻiIiahialoʻe have flowers with a reddish tint or red throat; this red flower color may be evidence of a Santalum ellipticum x S. freycinetianum hybridization.
ʻIIiahialoʻe are long-lived (greater than five years) plants with a fragrant heartwood. According to Joseph Rock [1974], "The older and bigger the tree the more valuable it becomes, as its fragrance increases with age...in small and young trees the roots only are fragrant." ʻIIiahialoʻe flowers develop in clusters, are mild to very fragrant, and perfect (have both male and female parts). Blooming seems to be sporadic (but more common in spring and summer) in the wild and more continuous in cultivation. Pollinated flowers develop into reddish or dark purple drupes (fleshy fruits with a single seed) with either shiny or dull skin. Birds, particularly red-vented bulbuls in the lowlands, are attracted to the ripe fruits. Therefore, if you wish to harvest seeds for future propagation, you should pick them as soon as they turn color, or protect the still-green fruits with a party-favors net bag until they ripen. Do not harvest still-green fruits because the seeds inside will not (normally) germinate.
Growth Requirements
General
Coastal Santalum ellipticum are usually prostrate to short shrubs with succulent leaves, while more inland ʻiliahialoʻe tend to be taller shrubs or trees with more papery leaves. Therefore, you should inquire about the origin of your ʻiliahialoʻe to determine if it is the right type for your location (e.g., Do you live in a beach house or upland getaway?), and decide where to plant it in your landscape. Short ʻiliahialoʻe can be used to create an informal (i.e., lightly pruned) hedge, while treelike forms, with a little pruning, can be made into a nice shade tree.
When acquiring or planting your ʻiliahialoʻe, it's important to remember that it is a hemiparasitic plant, dependent (at least when young) on a companion host plant and that its roots, and therefore its health, will be connected to the host plant for years; research and observations on how long this dependency lasts are currently inconclusive. In our experience, ʻiliahialoʻe seedlings without a host plant will live for about one year. If possible, try to get/buy an ʻiliahialoʻe seedling that is already sharing its pot with a host plant. If this isn't possible, then either, (1; preferred) repot it with a host plant and keep the two together for a while before planting them out together in your landscape, or (2) plant your ʻiliahialoʻe in your landscape near an established host plant. Fortunately, ʻiliahialoʻe doesn't seem to be too picky about the species when it comes to host plants. While we cannot provide you with a complete list (because we just don't know), we can recommend planting upland ʻiliahialoʻe near ‘āweoweo, koai‘a, or naio, and planting coastal ʻiliahialoʻe near ‘ākulikui, ‘ilima, or pōhinahina; look for a new webpage soon at A Native Hawaiian Garden on the results of a host plant experiment I (Koebele) am currently conducting.
ʻIliahialoʻe does best in a site with full sunlight for all or most of the day, but can tolerate a bit of shade. Just after planting, keep a daily watch on your seedling to see how it is faring. If it shows any signs of water-stress such as wilting, give it a drink and consider constructing a temporary "umbrella" to shade it. You will know it has established itself in your landscape when it starts to rapidly put out a flush of new leaves. These new leaves will be tinted bluish-red, red, or purple, in contrast to the pale green leaves of the pre-host seedling.
After your ʻiliahialoʻe is established and growing, water it approximately once a month during the dry months of the year. Do not overwater an established ʻIliahialoʻe since this can kill it; black sooty mold on its leaves is a good indicator you are overwatering. ʻIliahialoʻe can tolerate extreme heat, drought, and strong winds. Coastal types are tolerant of salt spray. ʻiliahialoʻe don't seem to be fussy about soil type and will grow in sandy and coralline soils, lava/cinder, clay, and even heavily degraded or eroded soils.
Both ʻiliahialoʻe seedlings and established in-the-ground plants seem to need iron. And often, the natural soil provides enough iron and other nutrients that established in-the-ground ʻiliahialoʻe do not require fertilizers. However, if your ʻiliahialoʻe is off-color (i.e., yellowing) or barely grows, try applying a balanced controlled-release fertilizer with minor elements (including iron), or monthly foliar feedings with an organic or inorganic water-soluble fertilizer diluted to ⅓ to ½ the recommended strength. A good source of iron is iron chelate, which you can buy in either a liquid or granular form. Apply the iron chelate two to three times a year as directed.
Avoid pruning ʻiliahialoʻe unless it is absolutely necessary, and then only prune by hand in stages over time. Additionally, make sure the host plant(s) does not over-shade your ʻiliahialoʻe and prune it if needed. Also, be careful using herbicides around ʻiliahialoʻe because of possible root connections between your ʻiliahialoʻe and the weeds you are trying to kill. The safest course of action is to always weed by hand around your plant. Merlin et al. [2005] recommend that "weeds within a radius of the tree equal to about twice its height should be" removed by hand or machine.
Pests and Diseases
ʻIliahialoʻe can resist most pest attacks, but may infrequently become infested by scale insects or whiteflies. Occasionally, insects such as cockroaches and sowbugs will chew on the stem/trunk at ground level. Snails and slugs too may also feed and potentially girdle seedlings. Refer to the Pests & Diseases page for ways to protect your ʻiliahialoʻe seedling and deal with these pests.
Uses
Ancient Hawaiian
The fragrant heartwood of ʻiliahi was pounded into a fine powder and then re-pounded into newly-made kapa to mask its bad odor, or mixed with coconut oil when waterproofing the kapa [Krauss 1972; Kepler 1985]. The wood was also sometimes fashioned into an ʻūkēkē (musical bow) [Buck 1964], or used as firewood [Wagner 1986]. The wood was favored for making the pola, the platform on a double-hulled canoe [Holmes 1981]. For dandruff and head lice, Hawaiians made a shampoo containing an infusion of ‘iliahi leaves [Krauss 1972].
According to Ka‘aiakamanu & Akina [1922], to treat some venereal diseases, ‘awa (Piper methysticum) was combined with wood shavings of ‘iliahi, nīoi (Eugenia reinwardtiana), ‘ahakea (Bobea spp.), and kauila (cf. Alphitonia ponderosa). And, to heal severe sores, ‘iliahi, manena (Melicope hawaiensis), and ‘ahakea shavings were combined with ‘awa, and ‘ōhi‘a ‘ai bark (Syzygium malaccense). Unfortunately, with so many other plant ingredients, it is difficult (impossible?) to verify that ‘iliahi was the active ingredient in these treatments.
Modern
ʻIIiahi and ʻiIiahialoʻe flowers, leaf-buds, and leaves are used in lei [McDonald & Weissich 2003], a likely ancient but unrecorded practice. The fragrant wood is valued for carving chests and other decorative boxes, furniture, and religious statues. The oil from the heartwood is used for cosmetics, perfumery, scented soaps, aromatherapy, and for medicinal purposes [Merlin et al. 2005].
Special Features and Information
General
There are about 1,000 species worldwide in the family Santalaceae [WikipediA;Santalaceae]. This includes several species endemic to Hawai‘i in the genera Santalum, Exocarpus, and Korthalsella. Currently, there are six endemic species of Santalum in Hawai‘i. [Flora of the Hawaiian Islands].
Both ʻiliahi and ʻiliahialoʻe are hemiparasitic. This means they derive some nutrients from another nearby plant through their roots, but are not totally dependent on the other plant. By contrast, the native hulumoa (Korthalsella spp.), kaunaʻoa (Cuscuta sandwichiana), and kaunaʻoa pehu (Cassytha filiformis), appear to be fully parasitic, meaning they are completely dependent on another plant for nutrients.
The Hawaiian Sandalwood Trade
(Our paraphrased summary of a more detailed account by Merlin & VanRavenswaay [1990].)
As with the other Hawaiian sandalwoods, ʻiliahialoʻe was harvested during the Sandalwood trade in Hawai‘i. The trade was fueled by greedy merchants in America, China, and Hawai‘i, as well as the Hawaiian monarchy.
In the late 1700s, due to China's (as well as a few other countries) insatiable demand for sandalwood, the white sandalwood (Santalum album), imported from India, was becoming scarcer and scarcer because of over-harvesting. With fewer imports from India, and with the aid of American fur traders, China turned its attention to Hawai‘i's endemic sandalwoods.
From the 1790s to the mid-1830s, ʻiliahi populations were devastated while the Hawaiian people who harvested the wood experienced incredible hardships. Thousands of Hawaiians, ordered by their aliʻi under Kamehameha I (the Great), left their homes and lo‘i (terrace gardens) to work upland cutting down and transporting sandalwood which they carried on their backs. Many of these makaʻāinana (commoners) died from exposure to the cold, exhaustion, malnutrition, or disease. And, with no one in the lo‘i growing food, Hawaiʻi suffered one of the worst famines in its history. Ali‘i, who initially profited from the harvested sandalwood, were soon in debt, exploited by foreign traders selling them exotic goods at vastly inflated prices. Meanwhile, in China, the Chinese began calling the Hawaiian Islands, Tang Heung Shan, or the "Sandalwood Mountains."
By the mid-1830s, the sandalwood supply was nearly exhausted in Hawai‘i and the remaining inferior wood was driving demand and prices down. It was around this time or perhaps somewhat later that merchants tried to sell naio (Myoporum sandwicense), which also has a fragrant wood, as genuine sandalwood for a second time with little success; there is a report of one unsuccessful attempt to sell naio to the Chinese around 1790. From this trade, naio acquired the sorry nickname "bastard sandalwood."
In 1839, King Kamehameha III (Kauikeaouli) finally placed a kapu (royal permission was required to harvest) on the remaining ʻiliahi, reserving two-thirds of it for himself. And by 1840, the Hawaiian sandalwood trade was over.
Fortunately, the Hawaiian people, the land, and the ʻiliahi have survived, but not without consequences. While not nearly as common as in the past, wild ʻiliahi and ʻiliahialoʻe can still be seen relatively easily in their native habitat; however, very large trees are still difficult to find.
Hawaiian Name
ʻIliahi is a reference to the reddish color of the plant's new leaves or the tree in general when it is in full bloom [Merlin & VanRavenswaay 1990]. Lāʻau ʻala translates as "fragrant wood" [Pukui & Elbert. 1986].
Etymology
Santalum comes from the Greek word santalon, which in turn is from the Arabic word sandal, for the Indian sandalwood (Santalum album) [Florabase]. The species name, ellipticum, is Latin and means "elliptic," [Latdict] in reference to the shape of the plant's leaves.
BPK