Native Plants of Hawai‘i - Wikstroemia uva-ursi var. uva-ursi

Wikstroemia uva-ursi var. uva-ursi

Thymelaeaceae or Daphne family

Synonyms: Diplomorpha uva-ursi, Wikstroemia foetida f. humilis, Wikstroemia foetida var. glauca, Wikstroemia monticola var. occidentalis

ʻĀkia

Aoaoa, Kauhi

Fish poison plant, Hillside false ʻōhelo

Natural Range & Environment

Wikstroemia uva-ursi var. uva-ursi is rare or scattered, dry ridges, open hillsides, ledges, windswept headlands, clay flats, ʻaʻa lava, coastal, and low, dry, open, alien vegetation on Oʻahu, Molokaʻi, and Maui, and reported from some inland localities such as ʻIao Valley, Maui, from about 10 to over 1,375 ft (3-420 m) [Wagner et al. 1990].

One of the most commonly seen and used urban plants, ʻākia has been used in the landscape for many years, usually as accent shrubs. Here are a few cultivated examples of many out there in our communities.

Description

Wikstroemia uva-ursi are densely branching shrubs, prostrate or sprawling shrubs up to 1.5 m (ca. 5 ft). Young branches may have dense gray, yellow or reddish-brown fuzz. Leaves are dark to grayish green on upper surfaces; lower surfaces are lighter, sometimes glaucous. The small (3.5-8 mm), yellow tube-like flowers are unisexual, sometimes perfect, as on Maui. Fruits, usually containing a single seed, are bright red to dark crimson, orange or yellow, ovoid or elliptic, and 5-10 mm in diameter [Wagner et al. 1990].

Growth Requirements

General

ʻĀkia is not difficult to grow and has been a part of native Hawaiian landscapes for decades. The low-growing shrubs look very nice as accent plants or alone in black or red cinder beds, against rock walls or next to large lava boulders. It does need well-draining soil and prefers full sun and sufficient air movement. Black sooty mold can be the first indication that it is getting far too much water. ʻĀkia is drought, wind, heat and salt-tolerant natives, which may explain why it is one of the most widely used native Hawaiian plants.

Pests and Diseases

Sometimes, spider mites can be problematic and infest the underside of leaves. Pests & Diseases page for treatments.

Uses

Ancient Hawaiian

The bark of the ʻākia tree was traditionally utilized as a valuable source of fiber material for crafting ropes [Wagner et al. 1990]. According to B. Peterson (1990) he says that “species of Wikstroemia have furnished one of the strongest Hawaiian fibers, used in making ropes and braids. It is also said to have been used in making kapa. Measurements made from fibers of branches desiccated for 6 months demonstrated that the density of Wikstroemia fibers was about the same as that of New Zealand flax (Phormium tenax) and ramie (Boehmeria nivea)" [Auwahi Forest Restoration Project]. Additionally, the wood of the ʻākia, particularly from larger species, was employed as ‘auamo, or carrying sticks [Bishop Museum Hawaiian Ethnobotany Online Database], and was also utilized as ceremonial firewood in ʻanaʻana magic, as documented by Kamakau in 1991 [Medeiros et al. 1998].

In traditional Hawaiian medicine, the sap of ʻākia, mixed with niu (coconut) and kō kea (white sugarcane), was ingested along with ‘uala (sweet potato) as a purgative. Additionally, a mixture of the leaves and leaf buds of ʻākia, along with the bark of the ‘ōhi‘a ‘ai or mountain apple (Syzygium malaccense) and ‘uhaloa (Waltheria indica) root, niu, and kō ‘aina kea, a sugarcane variety, was prepared by pounding the plant material, adding water, straining it, and then consuming the liquid internally to treat conditions such as wai‘ōpua pa‘a (leukorrhea) and nae kūlou (shortness of breath) [Bishop Museum Hawaiian Ethnobotany Online Database].

Furthermore, the roots, bark, leaves, and stems of ʻākia were utilized by early Hawaiians as a method to stupefy fish known as hola. The plant parts were crushed, placed in a porous container, and submerged in saltwater pools to catch the fish. It is important to note that the ʻākia plant is not toxic to warm-blooded creatures, making the fish safe to consume after being caught using this traditional fishing technique [Neal 1965].

Is ʻĀkia Poisonous or Not?

There has been much debate surrounding the toxicity of ʻākia, a plant known for its alkaloids. Historically, ʻākia was used in ancient Hawaiʻi as a form of punishment for those who broke kapu, with the guilty party being forced to consume the plant's juice, resulting in seizures [Lincoln 2009]. Botanist Otto Degener (1945) mentioned that criminals were executed using a deadly drink made from ʻākia roots and bark. However, conflicting information exists, with some sources claiming that no parts of ʻākia are poisonous to mammals, including humans [Crowl 2007]. Experiments have shown that some species of Wikestroemia, the genus to which ʻākia belongs, may not be toxic. Handy and Handy (1972:239) distinguished between two types of ʻākia: a bitter variety and a mild variety. The bitter ʻākia, known as ʻākia ʻawa, was described as deadly poisonous, while the mild variety, ʻākia manalo, was said to be non-toxic and even used as a narcotic [Medeiros et al. 1998].

Given the conflicting information, it is advisable to err on the side of caution and refrain from ingesting any parts of ʻākia until more definitive research is available.

Modern

The fruits of this species can be used to create beautiful lei. Additionally, ethanol extracts from this plant have demonstrated anti-tumor properties. In terms of toxicity, How to Plant a Native Hawaiian Garden (Kenneth M. Nagata) notes: "In Hawaii, only the toxicity of Wikstroemia pulcherrima Skottb. has been studied extensively by Dr. Frank Tabrath. W. pulcherrima has caused mice to go to sleep. The toxicity of W. pulcherrima varies from high to zero toxicity even in the same plant at different times. Many people have eaten the berries for years without ill effects" [Nagata 1992].

Special Features and Information

General

Wikstroemia belongs to the Daphne family (Thymelaeaceae), where there are a dozen species endemic to the Hawaiian Islands. There are two varieties of Wikstroemia uva-ursi, the featured species on this page, and a second species, var. kauaiensis, endemic to Kauaʻi. It can be very difficult to distinguish the two varieties apart [Wagner et al. 1990].

One of its close relatives is the East Maui species, Wikstroemia monticola, which is similar to W. uva-ursi. However, a key distinction between the two is that W. monticola typically grows as a small tree, while W. uva-ursi is more of a sprawling shrub.

The common name "false ʻōhelo" is given to the ʻākia plant due to its fruits resembling the orange or red ʻōhelo berries of the Vaccinium species. Additionally, ʻākia is also known as the "fish poison plant" in some contexts.

Hawaiian Name

Botanist William Hillebrand (1888) identified the Hawaiian names for the genus as "akia" or "akea." He also suggested that the root of the word may be derived from the Fijian name for the genus, mati, and that the native name for the genus in Tahiti is ovao. Alternate names for this species include aoaoa and kauhi. The name ʻākia is also another name for Solanum nelsonii, a small endemic shrub in the Solanaceae or Nightshade family.

In addition to its botanical meanings, ʻākia also signifies fermentation and extreme sourness, as seen in some poi. For example, ʻai ʻākia refers to sour poi [Hawaiian Dictionaries]. The exact relationship between these names remains uncertain. Distinctive varieties of this genus include lau nui, mānalo, and pehu [Hawaiian Dictionaries].

Etymology

The genus is named for Johan Emanuel Wikström (1789-1856), a Swedish botanist and author of several papers on Thymelaeaceae [Gledhill 2008]. The specific and varietal name uva-ursi is from the Latin uva, grape or berry, and ursi, bear, literally "bear's grape" or bearberry [Gledhill 2008]. The varietal name kauaiensis, with -ensis added, will form a geographical epithet [Gledhill 2008], to the island of Kauaʻi, where it is endemic.

DWE