Delissea waianaeensis

leaf Main Plant Information

Genus

Delissea

Species

waianaeensis

Hawaiian Names with Diacritics

  • ʻOha
  • Hāhā
  • ʻŌhā
  • ʻŌhā wai

Hawaiian Names

  • Haha
  • Oha
  • Oha wai

Common Names

  • Delissea

Synonyms

  • Delissea subcordata var. kauaiensis

Names with Unknown Sources

  • Ohawai

leaf Plant Characteristics

Distribution Status

Endemic

Endangered Species Status

Federally Listed

Plant Form / Growth Habit

  • Shrub

Mature Size, Height (in feet)

  • Shrub, Small, 2 to 6
  • Shrub, Medium, 6 to 10

Mature Size, Width

Mature specimens may have a two or more feet wide canopy. The plants are single stemmed; or it is occasionally branched, usually as the result of an injury. [4]

Life Span

Long lived (Greater than 5 years)

Landscape Uses

  • Container
  • Indoor
  • Specimen Plant

Additional Landscape Use Information

The few delissea in cultivation have proved to be rather easy under cultivation and ʻōhā (D. waianaeensis) has been no acception. These rare plants will regularly flower and fruit even at very low elevations (i.e. less than 500 ft.) in pots or in the ground, provided that can be protected against slugs and snails. (Also, See Modern Use under Special Features and Information for this profile) [David Eickhoff, Native Plants Hawaiʻi]

Although the longevity of individual plants is not known, it is presumed to live less than ten years. [4]

Source of Fragrance

  • Fruits

Additional Fragrance Information

Fruits have a floral fragrance when crushed. [David Eickhoff, Native Plants Hawaiʻi]

Plant Produces Flowers

Yes

leaf Flower Characteristics

Flower Type

Showy

Flower Colors

  • Greenish-White
  • White

Additional Flower Color Information

The six to eighteen curved flowers are white to greenish white with the charcteristic dorsal knob found in Delissea spp. The flowers are much larger than either D. kauaiensis or D. rhytidosperma, which are both in cultivation.

Blooming Period

  • Sporadic
  • January
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • December

Additional Blooming Period and Fruiting Information

Flowering has been documented at various times throughout the year. [4] Most flowering, however, is from late December to August, and fruting continues from April to September. [1]

The berries are purple when ripe.

Mejiro or Japanese white-eye frequent the flowers and pierce the base to sip nectar. Red-whiskered, and perhaps Red-vented, bulbuls will eat the fruit, but do not strip the plants of all its fruitage. [David Eickhoff, Native Plants Hawaiʻi]

leaf Leaf Characteristics

Plant texture

  • Medium
  • Coarse

Additional Plant Texture Information

The leaves measure from 4 to about 12 inches and have toothed margins (edges).

Leaf Colors

  • Light Green
  • Medium Green

leaf Pests and Diseases

Additional Pest & Disease Information

Slugs and snails, especially African snails, are serious pests and will devestate even mature plants in a short while. Spider mites and aphids appear mostly under the leaves or in emerging growth. Rats are known to eat fruit and vegetation.

leaf Growth Requirements

Fertilizer

Drench or foliar fertilizer* applications along with a balanced slow release fertilizer with minor elements is beneficial every six months. Foliar feed monthly with kelp or fish emulsion, or a water-soluble fertilizer with a dilution of one-half to one-third of the recommended strength. [David Eickhoff, Native Plants Hawaiʻi]

* Drench feeding is a diluted liquid fertilizer applied directly to the soil area around the plant; whereas foliar feeding are light applications of diluted liquid fertilizer applied to the foliage (leaves) by means of spraying or another method to coat leaves.

Pruning Information

Remove spent leaves, flowers, and fruit for a clean appearance. Clean up leaves at base of plants where slugs and snails can hide. [David Eickhoff, Native Plants Hawaiʻi]

Water Requirements

  • Moist

Additional Water Information

ʻŌhā are fairly drought tolerant, but with less water the leaves are often smaller, and flower and fruit production low to nil. [David Eickhoff, Native Plants Hawaiʻi]

Soil must be well drained

Yes

Light Conditions

  • Full sun
  • Partial sun

Additional Lighting Information

Can take morning sun well, but should be protected from hot afternnon exposure. Seems to perform best with partial sun. [David Eickhoff, Native Plants Hawaiʻi]

Soils

  • Cinder
  • Organic

leaf Environmental Information

Natural Range

  • Oʻahu

Natural Zones (Elevation in feet, Rainfall in inches)

  • 1000 to 1999, 50 to 100 (Mesic)

Additional Habitat Information

This delissea is endemic to the Waiʻanae Mts., Oʻahu in seven distinct wild populations: Kapuna, Pahole, ʻĒkahanui, Mohiākea, Palikea Gulch, Kaluaʻā, Keālia, and Palawai. The U.S. Army Natural Resources Staff have reintroduced plants to Kahanahāiki from the Kapuna population aproximately 1800 meters (about 1.1 miles) away. [2]

ʻŌhā (D. waianaeensis) grows from about 1475 to over 1800 feet in diverse mesic forest usually on north-facing gulch slopes and sometimes gulch bottoms. [3]

leaf Special Features and Information

General Information

Delissea are members of the Bellflower family (Campanulaceae) which includes well over 100 Hawaiian endemic species.

Delissea is an endemic Hawaiian genus. Among the fifteen Delissea species, eleven are now extinct and the remaining four are critically endangered.

Etymology

The generic name Delissea is named for Jacques Delisse (1773-1856), a French physican and botanist from Mauritius, who served as naturalist on the D'Entrecasteaux expedition to the South Pacific in 1800-1804.

The specific epithet waianaeensis is in reference to the Waiʻanae Mountains, Oʻahu, where ʻōhā is endemic and very endangered.

Hawaiian Names:

Hāhā is a name also used for several native species of Brighamia, Clermontia, Cyanea, Cyrtandra, and Gunnera.

ʻŌhā and ʻŌhā wai are also general names for many of the Clermontia spp. ʻOha (without kahakō) is used by one publication. [5]

Background Information

Delissea waianaeensis is endemic to the Waiʻanae Mts. and is still extant (existing) there. [1]

Another species from the Waiʻanae Mts. is Delissea takeuchii, which has not been seen since 1987 and is now considered extinct. The few specimens known were found in the central and southern areas of the Waiʻanae Mts. in wet to mesic forests at about 1800 to 2100 feet in elevation. D. waianaeensis may have hybridized with D. takeuchii. [1]

Delissea takeuchii was cultivated by the late University of Hawaiʻi president Laurence Hasbrouck Snyder (1901-1986) at his residence in Mānoa Valley, Oʻahu. [1,5] This specimen, orginally collected near Honouliuli, is no longer existing. [1]

Regarding Delissea sobcordata:

Delissea waianaeensis has, and continues, to be erroneously referred to as Delissea subcordata. Thomas G. Lammers provides compelling data to show that Delissea subcordata was found only in the Koʻolau Mts., Oʻahu; whereas Delissea waianaeensis is restricted to the Waiʻanae Mts., Oʻahu in mesic to wet forests. Delissea subcordata subsp. subcordata was found in mesic forests in the southern portions of the Koʻolau Mts. from about 390 to over 1500 ft., but now presumed extinct and last collected 1934. Delissea subcordata subsp. obtusifolia was found in mesic forests the central Koʻolau Mts. from about 735 to nearly 1250 ft., also presumed extinct and last collected in 1932. The two subspecies had "disjunct populations in the central portion" of the range and came together around Waikāne. These "intergrades between the two subspecies" were referred to as the intermediate "var. waikaneensis," but more resembled the subsp. subcordata so as not to warrant a distinct varietal status. [1]

The subspecies subcordata flowered from early May through mid-October; fruiting June through October in the souhthern Koʻolau Mts. [1]

The subspecies obtusifolia flowered and fruited in October in the central Koʻolau Mts. [1]

Interestingly, subsp. subcordata was once cultivated on Tantalus, Oʻahu at botanist George C. Munro's (1866-1963) mountain house "Kira Ora." [1]

Early Hawaiian Use

There are no known uses for ʻōhā. However, it is quite likely that early Hawaiians were well aware of these plants.

Modern Use

Ōhā does well as an indoor plant with bright, but filtered light or morning sun with sufficient moisture, diluted drench feedings of fertilizer once or twice a month, and gentle air movement. Though protected from most pests indoor, still keep an eye open for spider mites. [David Eickhoff, Native Plants Hawaiʻi]

Additional References

[1] "Revision of Delissea (Campanulaceae-Lobelioideae)" by Thomas G. Lammers, pages 31, 32, 34, 35-36, 37, 38.

[2] "Population genetics of Delissea waianaeensis," by Shelley A. James (Hawaii Biological Survey), page 2.

[3] "Delissea subcordata (Oha) A 5-Year Review Summary and Evaluation," by USFWS, page 7.

[4] Taxon Summary: Delissea subcordata www.botany.hawaii.edu/faculty/duffy/DPW/2003.pdf

[5] University of Hawaiʻi at Mānoa "Named Buildings" http://libweb.hawaii.edu/names/snyder.html [Accessed 12/09/11]

[6] "Hawaiian Plant Life--Vegetation and Flora" by Robert J. Gustafson, Derral R. Herbst & Philip W. Rundel, page 84.

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