Part 1 Acanthaceae - Aizoaceae
We start off with a family represented in the islands by 14 naturalized, ornamental species. [A naturalized species is an alien that has become established in the islands and undergoes normal reproduction.] Representatives of two genera are shown here. The first is Asystasia gangetica, known commonly as the Chinese violet or as coromandel, a native of southeastern Asia, India, and parts of Africa.
This is an attractive plant that has escaped from cultivation and now occupies extensive areas in disturbed lowlands on all islands in the archipelago and on Midway Atoll. I have seen Asystasia along the pathway to Oneloa Beach (sometimes called Big Beach) in the Mäkena area of Maui; at Honolua Bay, a popular snorkeling beach on Maui's northwestern tip; and in the Hälawa Bay area in northeastern Molokaÿi where it typically forms a spreading mat of vegetation.
The second example is Justicia betonica whose common names include white shrimp plant and squirrel's tail. Photo 2 features a grove of this plant growing beside the trail leading to Pololü Valley on the Big Island's northeastern coast. A close-up of the attractive flowering head is shown in Photo 3. This species also hales from southeastern Asia, and is considered a potentially invasive weed in the Hawaiian Islands.
Readers who have visited California's southern coast may have seen a member of this family planted in dunes as a sand stabilizer: Mesembryanthemum crystallinum, better known as the ice plant. The Hawaiian Islands, and most other islands in the Pacific Basin, are home to their own beach plant, although it is not nearly as showy as the ice plant, unless one can get very close (Photo 4). The plant is Sesuvium portulacastrum, sea purslane in English, ÿäkulikuli in Hawaiian. This species is salt-tolerant and can be found growing on sandy substrates (Photo 2) or on lava (Photo 3); it occurs on all main islands plus several of the islands of the Northwestern Hawaiian Islands (or Leeward Islands; Papahänaumokuäkea in Hawaiian).
The second member of this family on the islands, familiarly called New Zealand spinach, is Tetragonia tetragonoides (Photo 6). This species serves as a substitute for spinach in areas where it is too hot to grow the real thing, hence its common name. It is native to New Zealand, Tasmania, Australia, Japan, and southern South America. According to Mabberley (p. 849), Captain James Cook fed this plant to his sailors, one of several green leafy vegetables useful against dietary deficiency diseases. It has been cultivated in the Hawaiian Islands and has escaped. It can be found growing in disturbed coastal habitats on most islands.
Mabberley, D. J. 2008. Mabberley's Plant-Book, 3rd Edn. Cambridge University Press, Cambridge.
October 24, 2011