Beach Naupaka, also known locally as “Hawaiian Half-Flower” (or simply “Naupaka”), is one of my favorite coastal plants. Its foliage and flowers are very attractive, and the plant itself is tremendously successful at colonizing its chosen environment. To say it is “ubiquitous” in the Hawaiian Islands is an understatement: it grows throughout the coastal zones of every one of the main islands and many of the tiny coral-and-rock islets of the Hawaiian Archipelago.
- The “Half Flower” of Beach Naupaka (Scaevola sericea). Kanaha Beach Park, north Maui.
Unfortunately, this admirable species has fallen victim to the confusion and contention of the botanical world’s “Taxonomy Wars”. As a result, Beach Naupaka may be assigned either of two competing scientific names, depending on the biased opinion of a particular author or researcher. But let’s save my “rant” on the subject of the taxonomic confusion surrounding this species for the end of this blog entry. First things first: Who, What, and Where is the Beach Naupaka?
Beach Naupaka or Naupaka Kahakai (Scaevola sericea) foliage and flowers, southeastern coast of Lana'i.
General Description
Beach Naupaka is native or endemic to most of the Pacific islands, including the Hawaiian Islands, occurring along beaches throughout the Pacific basin. It is a tall bush-like perennial shrub that commonly forms dense hemispherical mounds of light-green foliage, its branches taking root where they touch the ground. Although individual stands can grow to more than five meters in height, most are considerably wider than they are tall. The simple, smooth-margined leaves are 8-14 cm long, are broader at the tip than the base of the leaf, and their edges often curl back under themselves. They typically are crowded together at the tips of growing trigs. Beach Naupaka is sometimes called the “half-flower” because the flower heads have petals on just one side, making them appear to have been torn in half. The five petals are white or cream-colored, often with purple streaks. The flowers grow in small clusters from between the leaves at the stem tips and have a distinctively pleasant fragrance. The fruit is a fleshy spherical “drupe” 1.5-2 cm in diameter with sepal lobes persistent at the tip. The drupe turns from green to white when mature. Each fruit contains 2-4 seeds in a hard woody “stone” surrounded with corky tissue that allows the fruit to float in water.
Naupaka, Hala Trees, and Coconut Palms festoon the rocky shoreline of Pailoa Bay, Waianapanapa State Park, east Maui.
Habitat
Beach Naupaka is common in the hot, dry coastal areas of most of the Hawaiian Islands, with the exception of the smaller islets at the extreme northwestern end of the island chain. It grows naturally on sandy beaches, forming dense thickets on seaside cliffs and sand dunes. This adaptable species is also common on hillsides and lower mountain slopes, pasture lands, roadsides, and encroaching urban areas. It is able to survive in beach-front environments where the spray from breaking waves deposits large quantities of sodium salt on its leaf surfaces and high concentrations of sodium salt in its water source. It prefers sandy, well-drained soils. It is very drought tolerant and can withstand annual average air temperatures as low as -1 degree C; of course, temperatures in the plant’s natural habitat rarely are that low.
The fruit (or "drupes") of Beach Naupaka, Papaula Beach, north Maui.
Propagation and Invasive Qualities
Beach Naupaka is very adaptable and propagates quickly. In the state of Florida, it is considered an aggressively invasive weed, out-competing vulnerable native plant species. Its presence there was first reported in 1976, possibly introduced from Hawaii. This species’ most common method of propagation is from seed. The corky interior of the fruit allows it to float readily in water. The seeds are able to remain viable in salt water for more than a year, but they will only germinate in the presence of fresh water, as when washed up on a beach routinely subjected to moderate-to-heavy rainfall.
My rant: What’s In A Name?
Taxonomy is a field of study within the biological sciences that is devoted to the identification, naming, and classification of living things according to apparent common characteristics. It is also a field of study that attracts some of the world’s biggest egos and most anal-retentive personalities. The binomial system used to name individual species of plants and animals, while seemingly straight forward at first glance, can be so Byzantine in complexity that it perpetuates centuries-long struggles to give Latin names to simple creatures like Naupaka. To get an impression of just how complex the taxonomic naming process can be, go to the BIOLOGICAL CLASSIFICATION web page on Wikipedia (http://en.wikipedia.org/wiki/Biological_classification) and attempt to read through the section on Modern Systems of classification.
Fruit of Beach Naupaka (Scaevola sericea), Kanaha Beach, north Maui. Note the prominent sepal nodes on the tips of the mature drupes.
The following is an excerpt from the International Code of Botanical Nomenclature (ICBN) (Saint Louis Code, Electronic version), THE authoritative codex supposedly recognized by all the combatants in the field of taxonomy. This section of the code lays out how to publish a species’ name correctly. Note that this excerpt uses our own Naupaka as an example.
CHAPTER IV. EFFECTIVE AND VALID PUBLICATION
SECTION 2. CONDITIONS AND DATES OF VALID PUBLICATION OF NAMES
Article 33
33.2. If, for a presumed new combination, no reference to a basionym is given but the epithet of a previously and validly published name that applies to the same taxon is adopted, the new combination is validly published as such if, and only if, it would otherwise be validly published as the name of a new taxon (see also Art. 33.6(d)).
Ex. 3. Scaevola taccada was validly published by Roxburgh (1814) by reference to an illustration in Rheede (Hort. Malab. 4: t. 59. 1683) that appears to be its sole basis. As the name applies to the species previously described as Lobelia taccada Gaertn. (1788), it is treated as a new combination, S. taccada (Gaertn.) Roxb., not as the name of a new species, even though Gaertner is not referred to in Roxburgh’s protologue.
The following is the United States Department of Agriculture’s official plant profile for Naupaka.
USDA NRCS PLANT PROFILE
Scaevola sericea Vahl var. taccada (Gaertn.) Thieret & B. Lipscomb
Genus Scaevola – naupaka
Species Scaevola sericea Vahl – beach naupaka
Variety Scaevola sericea Vahl var. taccada (Gaertn.) Thieret & B. Lipscomb – beach naupaka
Alternative Botanical Names Scaevola taccada (most commonly used – incorrectly!!!)
Lobelia taccada Scaevola fauriei Scaevola frutescens Scaevola koenigii Scaevola plumerioides
Beach Naupaka (Scaevola sericea) colonizing the sand berm along a stretch of Kanaha Beach, north Maui.
So… did you notice that the USDA’s plant profile and the ICBN do not agree on the correct name for poor old Naupaka? If these two august and widely respected authorities cannot agree on a taxonomic designation, how can you expect anyone else to do so? This plant was first officially identified in 1683, but after almost 330 years, researchers, educators, and hobbyists still can’t agree on the scientific name!
Blame it on the Web?
Quite apart from the dueling egos in the academic world, controversies over taxonomic names is perpetuated by the prevalence of “Monkey-See-Monkey-Do” naming practices on the Web, and the ignorance, stupidity, and outright carelessness of webmasters who want to make it look like they actually researched the taxonomic issue but really didn’t. It’s a simple matter to trace the original source of a problematic species name back through all of the copycat websites by looking for repeated spelling errors and persistently incorrect genus/species attributions common to the original perpetrator and all his imitators. A little more diligent research on the part of the webmasters of botanical websites would go a long way to alleviating this problem, but “due diligence” is not practiced extensively on the Worldwide Web.
