Artemisia australis
Asteraceae or Sunflower family
Synonyms: Artemisia australis var. eschscholtziana, Artemisia australis f. menziesioides, Artemisia australis var. microcephala, Artemisia australis f. pauciflora, Artemisia australis f. skottsbergii, Artemisia eschscholtziana, Artemisia hillebrandii, Artemisia microcephala
ʻĀhinahina
Hinahina, Hinahina kuahiwi
Oʻahu wormwood
Natural Range & Environment
Artemisia australis is endemic to all the main Hawaiian Islands, where it primarily grows on exposed cliff faces from near sea level to 1,065 m (3,494 ft) [Wagner et al. 1990].
ʻĀhinahina with flowers (Photograph courtesy of G.D. Carr ©.). Close-up of silvery leaves. Wild O‘ahu plant in its typical habitat — a rocky cliff face (Photograph courtesy of Andrew Evens [awevans99] CC BY-NC 4.0.). A cluster of small and one large Maui ʻāhinahina planted in two gardens, respectively, along with other native Hawaiian plants (Photographs courtesy of Forest & Kim Starr CC BY 3.0 US.). Generally, ʻāhinahina on O‘ahu are greener than those on Maui.
Description
Artemisia australis is a small to medium-sized shrub with a lifespan greater than five years. ʻĀhinahina vary in leaf shape and color. While all ʻāhinahina have finely divided leaves (see photographs above), some forms, such as those found on Ni‘ihau, Moloka‘i, and Lāna‘i, have leaves divided into broader segments than ʻāhinahina growing on the other Islands [Wagner et al. 1990]. The amount of leaf pubescence (hairiness) can also vary with location for wild plants and with environmental conditions for cultivated plants (e.g., less light or more water tends to yield less pubescent — greener — plants). From our observations, ʻāhinahina from O‘ahu tend to be less pubescent and, therefore, greener than plants from Kaua‘i or Maui; we are unable to comment on the pubescence of ʻāhinahina from the other Islands.
ʻĀhinahina leaves are faintly to strongly aromatic, particularly when crushed or rubbed, and have a sage- or anise-like (or, for locals, lychee-like) fragrance. The raw leaves also have a very bitter taste.
ʻĀhinahina has small yellow to brown daisy-like compound flowers with outer female and inner perfect (bisexual) florets [Wagner et al. 1990] that develop on branched spikes that peek up above its foliage. Each pollinated floret develops into a brown ribbed achene (single-seeded fruit). Artemisia australis might possibly hybridize with other Artemisia species, both native (e.g., A. mauiensis [Wagner et al. 1990]) and non-native in Hawai‘i; the naturalized mugwort (A. vulgaris) has been successfully crossed with other Artemisia species [James et al. 2000] and even with a chrysanthemum [Deng et al. 2010]. Therefore, if you intend to collect and sprout seeds from your ʻāhinahina, first look around your neighborhood for other Artemisia species and chrysanthemums, and then consider bagging and hand-pollinating your plant to be extra safe. ʻĀhinahina cuttings root relatively easily, making it the safest way to generate new plants.
Growth Requirements
General
Artemisia australis requires little care and is a striking addition to any landscape. Use it as either an accent or, spaced about three feet (1 m) apart, as a hedge. ʻĀhinahina is an excellent replacement for the popular and non-native Dusty Miller (Senecio cineraria). ʻĀhinahina can also be kept in a container; gradually increase the pot size as your plant grows until it is the size you want.
Wild ʻāhinahina are most often seen growing directly out of cracked rocks (i.e., cliff faces). Let this be your guide for soil or media selection. In the ground, if your soil is mostly clay and/or drains water poorly, consider creating a mound of cinder or lava rock and planting your ʻāhinahina on top. If you intend to keep your ʻāhinahina in a container, fill the container with black cinder and a bit of sphagnum peat moss (i.e., 50% or more cinder).
Water your new ʻāhinahina about once a week until it is established in the ground (i.e., for one to two months) and is putting out new growth. Then, cut back dramatically on your watering and only water enough to prevent wilting of the plant's leaves. The surface soil surrounding your ʻāhinahina should be dry most of the time.
ʻĀhinahina does best in a site with full sun for most of the day. Those placed in a shady location will grow slowly (or not at all) and will be less silvery. Too much water or fertilizer will also decrease the silvery color of their foliage.
ʻĀhinahina don't grow super fast, so be patient if you want a large shrub; typically they increase in height and width by about one foot (30 cm) per year until they reach their mature size (3 to 6 ft; 1 to 2 m). Trying to speed your plant's growth with fertilizer can result in less silvery leaves, so use any type of fertilizer sparingly. ʻĀhinahina can tolerate heat, drought, strong winds, and some salt spray. Plants are also tolerant of hand-pruning. Do so either to remove the occasional dead branch or maintain a desired shape or size. Since ʻāhinahina flowers are not as attractive as its silvery leaves, you may want to prune them away as well to direct more of the plant's energy to leaf growth. See Description above for advice on collecting seeds and rooting cuttings.
Pests and Diseases
In our experience, most pests seem to avoid ʻāhinahina, with the exception of spittlebugs, maybe because of its aromatic leaves. Refer to the Pests & Diseases page for how to deal with this pest.
Uses
Ancient Hawaiian
According to Ka‘aiakamanu & Akina [1922],ʻāhinahina, mixed with other plant ingredients, was used to treat asthma, lung problems, and high fevers.
Modern
ʻĀhinahina is occasionally used in lei and flower arrangements.
Special Features and Information
General
Asteraceae is a very large family of mostly herbaceous plants with about 32,000 species within 1,900 genera with a subpolar to tropical worldwide distribution. Nearly all Asteraceae have what appears to be a single "daisy"-type flower that is actually a composite of several much smaller flowers [WikipediA:Asteraceae]. There are also about 250 native and non-native Asteraceae in Hawai‘i [Flora of the Hawaiian Islands].
There are about 500 species in the genus Artemisia worldwide. Well-known non-Hawaiian Artemisia species include: Absinth wormwood (Artemisia absinthium) used to infuse absinthe and other spirits; tarragon (A. dracunculus) used in food; several species of the ubiquitous sagebrush of the American West [WikipediA;Artemisia]; and the common mugwort (A. vulgaris) used in Korean cooking to flavor rice cakes, soups, and other dishes.
There are three native species of Artemisia endemic to the Hawaiian Islands: A. australis found on all the main islands, A. kauaiensis found on Kauaʻi, and A. mauiensis found on Haleakalā, Maui.
Hawaiian Name
ʻĀhinahina comes from ʻāhina, which means "gray, gray- or white-haired," referring to the plant's color. Hina also means "gray," with hinahina meaning "very gray." The added kuahiwi, which means "mountain," refers to the plant's montane habitat [Pukui & Elbert 1986].
Etymology
The genus name, Artemisia, is derived from Dioscorides’ name for Artemis (Diana), wife of Mausolus of Caria in Asia Minor [Gledhill 2008]. The species name, australis, means "southern or pertaining to the south" [Gledhill 2008], possibly a contrast to better-known northern Artemisia species? In fact, the Boreal sagebrush or Northern wormwood (Artemisia campestris subsp. borealis) is one of the northernmost species of Artemisia, thriving in the tundra of the Arctic [Artemisia campestris].
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