Friday, June 05, 2009

Lagunaria patersonii

Lagunaria patersonii | Norfolk Island Hibiscus

Lagunaria is a small genus from from Norfolk and Lord Howe Islands in the South Pacific, and the coastal and inland areas of north Queensland. Until recently, Lagunaria was regarded as a monotypic species. It is believed its closest relative is Howittia, a monotypic Australian genus.

Lagunaria is known by a variety of common names, including Queensland Pyramid Tree, Cow Itch Tree, Norfolk Island Hibiscus, Whitewood, and Primrose Tree. It is a pyramidal-shaped tree, growing to 15m in height. The leaves are gray-green with flowers ranging from a pale pink to an almost purple color. There is a named variety 'Royal Purple' which has rosy-purple flowers. Caution: After flowering, Lagunaria produces bristly seed capsules that cause eye and skin irritation. Lagunaria has been introduced into the United States and can be found along the California coast as well as the inland valleys. Lagunaria tolerates reduced watering once established.

Until recently Lagunaria was regarded as monotypic with Lagunaria patersonii being the sole member of the genus, but with two recognised subspecies: ssp. patersonia and ssp. bracteatus. The Queensland population has recently been re-classified (2006) as a separate species Lagunaria queenslandica, however, until it become more clear as to whether this re-classification will be generally accepted, the earlier classification is retained here.

Lagunaria patersonii ssp. patersonia is confined to Lord Howe and Norfolk Islands. This subspecies is more robust in habit and has larger, scaly leaves and is generally found in rainforest.

Lagunaria patersonii ssp. bracteatus occurs in Queensland, generally found in non-rainforest areas often along rivers and creeks. All Lagunaria patersonii plants in mainland New South Wales were introduced.

As far as the specific name Lagunaria, there is some disagreement as to the correct spelling. For the most part, Australians refer to this species as Lagunaria patersonia, however I support the spelling Lagunaria patersonii, frequently used in Europe and the US. Over the last 2 centuries, Lagunaria has undergone several name changes, and a quick search of the IPNI website reveals several names associated with it. It appears that in August of 1831, G. Don published the name Lagunaria patersonii and cited Hibiscus patersonius Andrews and Lagunaea patersonia Sims as synonyms. This was later "corrected" to Lagunaria patersonia, perhaps in deference to Lagunaea patersonia Sims. However, the name Lagunaea patersonia seems unlikely on two counts: first, the defunct genus Lagunea consisted of mostly herbaceous species (like Hibiscus lobatus) that were later merged into Hibiscus. Second, based on the rules of botanical Latin, patersonia should have been rendered patersonii. According to "Botanical Latin" by William T. Stearn, "The International Code of Botanical Nomenclature recommends that when a new specific or infraspecific epithet is taken from the name of a man it should be formed in the following manner: When the name ends in a consonant, the letters ii are added (thus ramondii from Ramond), except when the name ends in er, when i is added (thus kerneri from Kerner). When epithets taken from the name of a man have an adjectival form they are formed in a similar way, e.g. Geranium robertianum, Tulipa gesneriana, Asarum hayatanum." Thus, even if the name was to have taken an adjectival form it would have been rendered Lagunaria patersoniana.

Likewise, the current International Code of Botanical Nomenclature (ICBN) states:
"Article 60C.1. b If the personal name ends with a consonant (except -er), substantival epithets are formed by adding -i- (stem augmentation) plus the genitive inflection appropriate to the sex and number of the person(s) honoured (e.g. lecard-ii for Lecard (male), wilson-iae for Wilson (female), verlot-iorum for the Verlot brothers, braun-iarum for the Braun sisters, mason-iorum for Mason, father and daughter)." Thus, if for the sake of argument, Paterson was female, it whould have been rendered Lagunaria patersoniae.

It seems from the beginning, Lagunaria patersonii has been plagued with misapplied or misspelled binomials. Thankfully, the current RULES AND RECOMMENDATIONS of the ICBN code allow for correction: CHAPTER V. REJECTION OF NAMES Article 51.1. A legitimate name must not be rejected merely because it, or its epithet, is inappropriate or disagreeable, or because another is preferable or better known (but see Art. 56.1)

Historical Information: The genus was named in honour of Andres de Laguna (d. 1560), a Spanish botanist (and physician to Pope Julius III), and the species in honour of a Colonel W. Paterson who first sent the seeds of the species to England.

Historical Reference: The tree is very shapely and ornamental in appearance, and is worthy of being planted far more extensively than it is. Any Sydney nurseryman can supply it. It should do well in all our sea-coast suburbs,such as Waverley, llandwick, and the Illawarra suburbs. The Manly Municipal Council has one or two in the Reserve near the jetty, but I cannot call to mind many about Sydney. In Adelaide I noticed a large number planted by the sides of the road, on the North Terrace. They were planted alternately with other trees, and were healthy-looking and ornamental. I have not at all a doubt they would do even better for street-planting in Sydney, for we have a more humid climate and a more saline atmosphere than has that beautiful city of our sister State.

   The Forest Flora of New South Wales
   By Joseph Henry Maiden, 1912