Native Plants of Hawai‘i - Abutilon eremitopetalum

Abutilon eremitopetalum

Malvaceae or Mallow family

Synonyms: Abortopetalum eremitopetalum, Abutilon cryptopetalum

No known ancient Hawaiian name

(see Hawaiian Name below)

Hidden-petaled abutilon, Hidden-petaled ʻilima

Natural Range & Environment

Abutilon eremitopetalum is an extremely rare and endangered abutilon. It is only found in shrublands and dry forests from 210 to 520 m (689 to 1,706 ft). It is endemic to eastern Lānaʻi (Kānepuʻu, Kehewai, and Kalulu and Maunalei valleys), but was also previously recorded from Kaʻā (northwest), Mahana (east), and Pāwili (northeast) [Munro 2007, Wagner et al. 1990]. The plants at Kānepuʻu were introduced by George Munro, with at least some of these originating from Kalulu [USFWS 1995]. A new population of about 60-70 plants was discovered in Kehewai Gulch in 1987 [Wagner et al. 1990].

Abutilon eremitopetalum flowers can be variable. Three examples are seen here with the calyxes being narrow or round, hirsute (hairy) (Courtesy of G.D.Carr) or having short hairs (downy), shades of green or flushed with red. The "hidden petals," with the calyx removed and parts identified, expose lime green-color petals. The fresh flowers, green and ripe fruit with a brown calyx covering the fruit, containing seeds, are often obscured by the large leaves of the shrubs.

Description

Abutilon eremitopetalum is a sprawling, pubescent shrub that typically grows 2–10 ft (0.6–3 m) tall. The leaves are simple, alternate, heart-shaped (cordate-ovate) blades, measuring 7–12 cm long with toothed margins and are grayish-green and covered in soft hairs.

The flowers are solitary or paired and appear in leaf axils. The name "eremitopetalum" translates to "hidden petal," referring to the lime green petals, which are shorter than the cup-shaped, 1–1.5 cm long green calyx (collective sepals that cover the petals) and not in seen at all! The unique flowers of the hidden-petaled abutilon themselves are indeed hidden among the large leaves and not readily detected from a distance. The flowers have a white to yellow staminal column that extends beyond the calyx. The prominent stamen cluster (staminal tube) is coral red and protrudes from the petals/calyx area.

As seen in these photographs, depending on the shape of the fruit inside, the calyxes can be narrow or round. The calyxes also may be hirsute (hairy) or pubescent (fuzzy), and with shades of green or flushed with red. The fruits, when dry and ripe, are hairy, brownish, cylindrical capsules roughly 8-10 mm long, which split into 8-9 segments, each containing fuzzy, kidney-shaped seeds.

From personal (Eickhoff) and photographic observations of cultivated plants, the blooming period seems to be sporadic throughout the year. Natural hybrids with Abutilon menziesii on Lānaʻi are known. Since Abutilon eremitopetalum can easily hybridize with A. menziesii, it is good to keep in mind that when these two grow near each other, the seeds should not be trusted as pure for either species. If you are intentionally making artificial (manmade) crosses, it will be good to use an appropriate covering so that each flower will not contaminate (accidentally spread pollen) to neighboring flowers. The few examples of artificial hybrids that I (Eickhoff) have seen display red petals partially appearing outside of the calyx, instead of totally being hidden inside.

Growth Requirements

General

Abutilon eremitopetalum thrives best in full sun and well-drained soil. While not the most impressive of the native abutlion species, it is nonetheless a unique and rare addition to a native landscape! Hidden-petaled abutilon is rather easy to grow and maintain in a landscape and performs much like koʻoloa ʻula (Abutilon menziesii).

For potted plants, it is recommended to use organic or natural fertilizers at low doses, around one-fourth the recommended strength. Over-fertilizing, especially with nitrogen, can lead to oversized leaves and fewer flowers. I (Eickhoff) have found that it seems in containers it appreciates more water than koʻoloa ʻula as long as it is in well-drained media. It can also tolerate more shade than koʻoloa ʻula, but still prefers full sun to grow and flower at its best.

With its attractive silvery-greenish foliage, this plant can be best used as an accent shrub. Once planted in the ground in a permanent location, A. eremitopetalum generally does not require fertilizers and will need minimal watering. It is drought- and heat-tolerant, but does not do well in salt spray. It is important to protect these shrubs from strong winds to ensure their health and longevity.

While, like other Malvaceae, it seems to handle pruning well as long as you do not remove more foliage and branches than is necessary at any one time.

Pests and Diseases

Chinese rose beetles can chew unsightly holes in leaves. Refer to the Pests & Diseases page for treatments.

Uses

Ancient Hawaiian

It is not known if the ancient Hawaiians utilized this plant.

Modern

Special Features and Information

General

Abutilon eremitopetalum belongs to the Mallow family (Malvaceae), a relative of hibiscus. Malvaceae contains about 4,200 species, with notables such as okra, cacao, durian, baobab, kenaf, and cotton [WikipediA;Malvaceae]. There are some 200 Abutilon species worldwide, found primarily in the tropics and subtropics [WikipediA;Abutilon]. In Hawai‘i, there are four native Abutilon species: the indigenous Abutilon incanum, and three endemic endangered species, A. eremitopetalum, A. menziesii, and A. sandwicense.

As indicated by its scientific name, the hidden-petaled abutilon (Abutilon eremitopetalum) is one of only three species known among the approximately 200 Abutilon species worldwide that have petals completely obscured from view! Only the fuzzy calyx, which covers the petals, and the prominent red stamen protruding from the flower are visible.

Abutilon eremitopetalum, was "discovered" by George Munro in 1930 in Maunalei Valley, Lānaʻi. Historically, the hidden-petaled abutilon has been considered rare, with populations widely scattered. The introduction of Axis deer (Axis axis) to the islands in 1867 has exacerbated the decline of this species due to grazing and antler rubbing. By 1951, only two or three plants were documented. The species was thought to be extinct by the early 1980s. However, in 1987, a population of approximately 60-70 plants was discovered on a slope in the north fork of Kaheʻa Gulch. By 1990, only 30 plants were observed by Steve Perlman of the National Tropical Botanical Garden, Kauaʻi. By June 1993, the population had dwindled to just seven specimens, with the remainder consumed by deer [USFWS 1995, Munro 2007]. Currently, about 100 plants exist in a single wild population in Kaheʻa Gulch. Fortunately, these plants are now cultivated and can be found in several public and private gardens.

Hawaiian Name

Currently, no known Hawaiian name has been found.

Etymology

The generic name Abutilon comes from the Arabic word abū-ṭīlūn (’abū ṭīlūn أبو طيلون), which means "Indian mallow." The name was first used in the 18th century as a Neo-Latin word [Wikipedia;Abutilon]. The specific epithet eremitopetalum literally means "hidden petaled."

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