The Flowering Plants of Hawaii
Part 12 Celastraceae - Ceratophyllaceae - Chenopodiaceae
Celastraceae are a primarily tropical family of 1,300 species in 100 genera (Mabberley, p, 163). The genus of interest to us here is Perrottetia which consists of 17 species with representatives in China, Malesia, Australia, Central America, the Solomon Islands and the Hawaiian Islands. The sole Hawaiian species is P. sandwicensis (see image), known in Hawaiian as olomea, pua`a olomea, and, on Maui, waimea. This small tree grows in wet forests on all of the islands except Ni`ihau and Kaho`olawe, which lack the wet habitat required. The photograph was taken in Kalöpä Park on the northeastern coast of the Big Island. The combination of shiny green leaves and red pigmented petioles and veins make this attractive tree easy to identify.
Sticks of olomea, along with pieces of kukui (Aleurites moluccana) wood, constituted the fire-making kit of early Hawaiians. A pointed piece of the softer olomea wood was rubbed rapidly in a groove of the harder kukui wood creating enough friction to light the fine particles of olomea that were worn off in the rubbing. Shreds of dry niu (coconut husk) were used to capture the flame from the smoldering olomea (Abbott, p. 93).
This small, cosmopolitan family consists of the single genus Ceratophyllum with species numbers ranging from two to as many as 30 (Mabberley, p. 169). The family is represented in the Hawaiian Islands by one species, Ceratophyllum demersum (see image), which is apparently known only from ponds on Maui and on the Big Island (Manual). It is known commonly as hornwort or coontail. This plant is often used as decorative and oxygen-producing greenery in aquaria. Casual disposal of aquarium water is a likely source of this plant in areas where it does not occur naturally.
As historically constituted, Chenopodiaceae, the pig-weed family, comprised 1,500 species in 100 genera (but see note below). The family is cosmopolitan in distribution with a large percentage of its members occupying severe habitats, e.g., deserts and regions of highly saline soil. Many are widespread weeds, such as the Russian thistle (Salsola kali subsp. ruthenica) the tumbleweed of the dry interior of North America. The family is also home to familiar edible plants, e.g., beets and Swiss chard (subspecies of Beta vulgaris ) and spinach (Spinacia oleracea).
The Manual lists five genera of chenopods in the islands with a total of 13 species; only one of which is endemic, Chenopodium oahuense (see images), known in Hawaiian as `äheahea, `ahea, and `ähewahewa, among others. This species, which is the only woody member of the genus, occurs on all of the main islands, except Kaho`olawe, as well as on several of the leeward islands. Leaves of `äheahea have a slight ammonia-like aroma. The plant in the photograph was seen in the open area just below Hale Pohaku (Okizaki Astronomy Center) on the Big Island.
Leaves of `äheahea were eaten in times of scarcity after being wrapped in ti leaves and cooked in an underground oven or on hot coals (Pukui and Elbert, p. 7). Branched pieces of wood were used in the construction of shark hooks. After Europeans introduced cattle and a variety of ungulates to the islands some native Hawaiians capitalized on the availability of sharpened horns and antlers for the construction of composite hooks such as that in the illustration (see image). The featured hook was made by Paul Elia, a Moloka`i craftsman who has since departed to join his `aumakua. In this example the wood is probably koa (Acacia koa).
Genera historically constituting Chenopodiaceae are now placed in Amaranthaceae (2,000 species in 175 genera) (Soltis et al., loc. cit.). Amaranthus, a well known genus within the historical Chenopodiaceae, was elevated to family status on the basis of molecular genetic data, which placed it in a basal (early evolutionary) position among the collection of genera.