Native Plants of Hawai‘i - Bonamia menziesii

Bonamia menziesii

Convolvulaceae or Morning glory family

Synonyms: Bonamia menziesii var. rockii, Breweria menziesii, Perispermum albiflorum, Perispermum menziesii

No known ancient Hawaiian name

(see Hawaiian Name below)

Hawaiian bonamia, Hawaiʻi lady's nightcap, Menzies' nightcap

Natural Range & Environment

Bonamia menziesii is a critically endangered liana endemic to all the main Hawaiian Islands except N‘ihau and Kaho‘olawe, but is now presumed extirpated from Molokaʻi [Flora of the Hawaiian Islands]. It grows primarily in dry to mesic forests and rarely in wet forests from 351 to 1,415 m (1,152 to 4,642 ft). USFWS estimated there were fewer than 175 wild plants when the species was federally listed in 1994. Since then, wild number estimates have fluctuated, primarily because of inadequate surveying. In their last 5-Year Review (2021), USFWS estimated that there are approximately 100 wild plants statewide. Fortunately, a few thousand seeds have been collected and stored by botanical gardens and government agencies [USFWS;ECOS]. Additionally, Bonamia menziesii is one of the few endangered native Hawaiian plants that is occasionally available for sale at local plant sales and garden shops.

Bonamia has dull green leaves and greenish white flowers. The ripe dry fruit capsules of Bonamia resemble those of the non-native baby woodrose. This mature plant looks great in addition to providing shade.

Description

Bonamia menziesii is an endangered endemic vine or liana (woody vine), with a lifespan of five or more years, that can grow to as much as 50 feet (15 m) in length. Its elliptic to ovate leaves can be silvery-gray to dull green, 1 to 3 inches (2.5 to 7.6 cm) long, and are often thick or leathery. Young leaves are normally covered with a soft silvery or yellowish-brown fuzz. As they mature, the leaves often become glabrous (without hairs) or nearly so, at least on their upper surface. Interestingly, seedlings grown under artificial light are glabrous, suggesting it is the spectrum or heat of true sunlight that induces the development of these hairs.

Small greenish-white funnel-shaped non-fragrant perfect (bisexual) flowers bloom sporadically year-round (in cultivation) and are often hidden by the leaves. While sparsely blooming plants are not particularly showy, a plant with many flowers can be quite spectacular! Pollinated flowers develop into dry tan capsules that look much like those of the non-native (introduced from India) Hawaiian Baby Woodrose, Argyreia nervosa. Each capsule contains 1 to 2 ovoid seeds, covered with a black pulp.

Growth Requirements

General

Bonamia menziesii is a climber. Take advantage of this by planting it near a fence, trellis, lamppost, or tree (see photograph above). It can also be kept as a container plant.

Bonamia grows best in a site with full sun for most of the day but can tolerate some shading, and seems to grow more quickly if it has something to climb. Once established, this vine requires little to no watering except during prolonged dry periods and is tolerant of drought, strong winds, and high temperatures. It will grow in lava/cinder, clay, organic-dominant, or mixed soils provided the soil drains well. (We have not tried to grow it in sand or coralline soil.)

In cultivation, Bonamia menziesii often grows quickly and begins flowering in about a year. Potted plants or those planted in nutrient-poor soil will benefit from the application of a controlled-release fertilizer with minor elements every 3 to 6 months. Alternatively, you can spray your plant with an organic or inorganic water-soluble fertilizer diluted to ⅓ to ½ the recommended strength.

Bonamia menziesii is a frequently-branching vine and, therefore, should be given plenty of room to spread out as it climbs. If necessary, you can tame or direct your plant with modest hand-pruning. However, remember this vine, unlike other native vines like hunakai or pā‘ū-o-Hi‘iaka, normally has a single main stem connected to all its roots. Therefore, do not cut or damage this main stem while pruning.

Pests and Diseases

Bonamia menziesii is occasionally attacked by black stink bugs; these can be removed by hand. Too frequent watering or a shady planting site can promote infestations of sap-sucking pests such as mealybugs, scale insects, and whiteflies, as well as the growth of a black sooty mold on the leaves and stems. These pests are often imported, farmed, and protected by ants. Refer to the Pests & Diseases page for treatments to control these pests.

Uses

Ancient Hawaiian

No ancient Hawaiian name or cultural use has yet been discovered for Bonamia menziesii. However, it is unlikely this native vine would have gone unnoticed by early Hawaiians, and, therefore, it's probable that both the name and any ancient uses for this plant were lost over time.

Special Features and Information

General

Convolvulaceae (Morning glory family) has about 1,600 species within 59 genera distributed in tropical to temperate regions throughout the world. Most species are vines or herbs [Britannia;Convolvulaceae].

Bonamia menziesii is related to some popular local food plants such as ʻuala or sweet potato (Ipomoea batatas) and ung-choi or swamp cabbage (Ipomoea aquatica).

In addition to Bonamia menziesii, other native Hawaiian Convolvulaceae include: the indigenous makihi (Cressa truxillensis); the endemic kaunaʻoa (Cuscuta sandwichiana); the indigenous hunakai (Ipomoea imperati), koali ʻawa (I. indica), whiteflower beach morning glory (I. littoralis), and pōhuehue (I. pes-caprae subsp. brasiliensis); the endemic Hawaiian moon flower (I. tuboides); and the endemic pāʻu-o-Hiʻiaka (Jacquemontia sandwicensis).

Hawaiian Name

No ancient Hawaiian name or cultural use has yet been discovered for Bonamia menziesii. Within this website, we will use the name Bonamia since this is the (shortened) name we most often hear others using for the species.

Etymology

The genus, Bonamia, is named for François Bonami (1710–1786), a French physician and botanist [Wagner et al. 1990]. The species name honors Archibald Menzies (1754–1842), a Scottish surgeon and naturalist, and the first non-Hawaiian to collect the species during his visit to the Hawaiian Islands [100 Princes Street].

BPK