Native Plants of Hawai‘i - Brighamia rockii

Brighamia rockii

Campanulaceae or Bellflower family

Synonyms: Brighamia remyi. Brighamia rockii f. longiloba

Pua ʻala

Hāhā, ʻĀlula

Cabbage-On-a-Baseball-Bat, Cabbage-On-a-Stick

Natural Range & Environment

Brighamia rockii is critically endangered (IUCN) and endemic to windward seacliffs from sea level to 470 m (1,540 ft) in Kalauapapa to Hālawa valleys, Hāʻupu Bay, and a few offshore islands on Molokaʻi, such as Huelo Rock [USFWS 1996]. It is extinct on Maui and Lānaʻi. Manual of the Glowering Plants of Hawaiʻi comments that "St. John (1969a) based Brighamia remyi on a single specimen (Rémy 309 bis, P) collected on Maui in the early 1850s. Rock (1919a) observed an inaccessible Brighamia at Maunalei Valley. Lānaʻi, which may also be referable to this species" [Wagner et al. 1990].

Wild Brighamia rockii (Photograph courtesy of Kenneth R. Wood (NTBG) CC BY-NC 4.0.). A nearly five-foot cultivated pua ʻala growing from a cement pot with abundant fragrant flowers.

Description

Pua ʻala is a succulent with a lifespan greater than five years and a mature height typically of 3-16 ft [USFWS 1996]. It most often grows as a single thick and fleshy central trunk with few, if any, side branches. Its bright lime to dark green semi-succulent leaves are clustered in a rosette at the top of the plant and range from 5–8 inches long. The roots extend into rocky crevices, while the swollen bases of the plants enable them to sway gracefully in the strong winds [Kimura & Nagata 1980].

Pua ʻala white five-point tubular flowers are arranged in clusters of 3-8 flowers [USFWS 1996] and have a sweet honeysuckle- or citrus-like fragrance. Early botanist George Munro describes the fragrance "like violets" [Munro 2007].

From photos of wild plants, it blooms in February, August, September, and November. Cultivated plants can bloom at any time of the year, usually begin when two to three years old, but can start as little as nine months [USFWS 1996]. Having lost its natural pollinators, which may have been birds [Pratt 2005] as well as insects, wild (and cultivated) plants must be hand-pollinated for fruit/seed development. Each pollinated flower develops into a sticky fruit (capsule) about ½-inch long containing many tiny seeds.

Growth Requirements

General

Pua ʻala can be challenging to grow unless certain things are observed under cultivation. For one thing, it is a magnet for spider mites, especially during the hot weather. Introduced African snails and slugs are serious pests and can destroy an otherwise healthy plant overnight. Without addressing both of the needs, you will likely find it very challenging to grow and flower them successfully! It does best in a terra cotta or cement container, or a black pot with extra black cinder. Pua ʻala can endure full sun, but I (Eickhoff) have found it grows better with a morning sun and avoiding the afternoon sun, which can scorch the leaves, especially in the hot summer months.

Pua ʻala should be grown as a succulent and requires dry to slightly moist media or soil. It has a thick succulent stem, helping it survive periods of drought. I (Eickhoff) prefer to let it dry to where the leaves are just beginning to droop before giving it a large drink of water. Overwatering will cause root or stem rot and quickly kill your pua ʻala or cause a fungal infection. However, in a container, it can be watered frequently if the media mix allows immediate drainage (e.g., a high % of black cinder). It can also tolerate strong winds and salt spray. The container should have sufficient weight to counterbalance the top-heavy crown of leaves and flowers.

It does well with monthly applications of half-recommended-strength foliar fertilizer or biannual applications of a slow-release fertilizer. The is no reason to prune pua ʻala, except to remove old yellow or brown leaves for a cleaner look.

Pests and Diseases

Carmine spider mites (Tetranychus cinnabarinus) frequently infest pua ʻala, causing leaf loss. Leaf-miners, too, can be an occasional pest. Snails and slugs, as well as rats and mice, can be serious pests, particularly for plants kept outside. African snails, especially, can quickly devour all the plant's leaves and stem tips and kill it. Overwatering and/or poor-draining media or soil can result in fungal rot of stems and roots, leading to death. Refer to the Pests & Diseases page for treatments for all the above.

Uses

Ancient Hawaiian

Charles Gaudichaud (1819) states that Hawaiians "used all fragrant plants, all flowers and even colored fruits" for lei making. Red, yellow, and purple flowers or fruits were often used to identify divine or chiefly rank. Therefore, with their place in oral tradition, it's possible the fragrant yellow flowers of pua ʻala were used for lei by early Hawaiians even though there are no written records [McDonald & Weissich 2003].

Hawaiians of former times in Wailau Valley (Molokaʻi) cultivated pua ʻala around their homes to enjoy the sweet, fragrant flowers [McDonald & Weissich 2003]. Otto Degener notes that the residents of Kalaupapa are said to still cultivate pua ʻala in their gardens and use the leaves as an edible vegetable, and adds that "Brighamia, called by various natives puaala, alula, ohaha, was eaten raw as a supposed remedy for consumption and various other diseases" [Degener 1973].

Modern

Special Features and Information

General

There are only two species in the endemic Hawaiian genus Brighamia, B. insignis and B. rockii, which are in the Campanulaceae or Bellflower family. Worldwide, there are approximately 2,000 species in 70 genera in Campanulaceae, with about 130 species found only in the Hawaiian Islands. The other native Hawaiian lobelioids are Clermontia, Cyanea, Delissea, Lobelia, and Trematolobelia — all endemic genera except for Lobelia.

Side-by-side, the two species of Brighamia are nearly indistinguishable. However, Brighamia rockii differs from B. insignis, which is endemic to Kauaʻi and Niʻihau, where it is now extinct in the wild, in that it has white flowers, while B. insignis has yellow flowers and tends to be a bit bigger, especially at the base [USFWS 1995]. Both species can grow to the amazing height of 16 feet! They are both perfectly designed for their windy habitat on steep coastal cliffs, where their roots penetrate crevices and hold tight, while their swollen, flexible trunk allows them to bend in strong winds. Unfortunately, both species have lost their natural pollinators and today require hand-pollination or native insects for fruit and seed production.

Hawaiian Name

Pua ʻala means fragrant, sweet-smelling, perfumed (ʻala) + flower (pua) [Hawaiian Dictionaries]. Another name for this species, Ālula, is sometimes spelled as ʻĀlula or Alula with or without diacritics ʻokina (glottal stop) or kahakō (macron). We have chosen to use Ālula for this website as it appears to be the commonly spelled in the majority of reliable references, including Manual of the Flowering Plants of Hawai‘i [Wagner et al. 1990]. The name Hāhā is also used for the two species of Brighamia, and Clermontia arborecens in the same family, Campanulaceae, as well as the Kauaʻi name for ʻapeʻape (Gunnera kauaiensis) [Hawaiian Dictionaries], but applies to both endemic Gunnera spp. [Flora of the Hawaiian Islands].

Etymology

The genus Brighamia is named in honor of William Tufts Brigham (1841–1926), geologist, botanist, and the first Director of the Bernice P. Bishop Museum, Honolulu, Hawaiʻi [WikipediA;William Tufts Brigham]. The specific epithet rockii is named for Joseph Frances Charles Rock (1884-1962), an Austrian-American botanist who did much to help our current understanding of native Hawaiian plants [USFWS 1996].

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