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Hibiscus clayi

leaf Main Plant Information

Genus

Hibiscus

Species

clayi

Hawaiian Names with Diacritics

  • Kokiʻo ʻula

Hawaiian Names

  • Kokio ula

Common Names

  • Clay's hibsicus

Synonyms

  • Hibiscus newhousei

Names with Unknown Sources

  • Newhouse hibiscus

leaf Plant Characteristics

Distribution Status

Endemic

Endangered Species Status

Federally Listed

Plant Form / Growth Habit

  • Shrub
  • Tree

Mature Size, Height (in feet)

  • Shrub, Tall, Greater than 10
  • Tree, Small, 15 to 30

Mature Size, Width

5+ foot spread.

Life Span

Long lived (Greater than 5 years)

Landscape Uses

  • Container
  • Hedges
  • Screening
  • Specimen Plant

Additional Landscape Use Information

Kokiʻo ʻula (H. clayi) are usually more compact shrubs when compared to other native hibiscuses and thus an excellent choice to use in landscapes with limited space.

This native hibiscus also makes a good container plant in 3 gallon or larger pots in sunny locations.

Source of Fragrance

  • No Fragrance

Plant Produces Flowers

Yes

leaf Flower Characteristics

Flower Type

Showy

Flower Colors

  • Red

Additional Flower Color Information

Flower colors range from medium to dark red.

Blooming Period

  • Year Round

Additional Blooming Period and Fruiting Information

Most kokiʻo ʻula are usually in constant bloom.

leaf Leaf Characteristics

Plant texture

  • Fine
  • Medium

Additional Plant Texture Information

Leaves range from over an inch to nearly 4 inches.

Leaf Colors

  • Medium Green

Additional Leaf Color Information

The smooth-edged leaves are green and shiny.

leaf Pests and Diseases

Additional Pest & Disease Information

Plants are prone to sucking insects. Chinese rose beetles can be removed by hand. The native red hibiscuses are just as prone to attract the hibiscus erineum mite as the non-native red hibiscuses.

leaf Growth Requirements

Fertilizer

Fertilize kokiʻo ʻula using a 2-1-3 or 2-.5-3 ratio with minor elements. It is important to keep the phosphorus low because it tends to accumulate and prevents the nitrogen and potassium from working. Minor elements such as magnesium and iron are also important to maintain healthy green foliage. [1]

Pruning Information

Generally this native hibiscus can left as free forming shrubs. Hedges may need some pruning two or three times a year. Clear out dead and diseased wood for minor shaping. For pruned shrubs, they are best kept at 6 to 8 feet tall in a landscape setting.

Water Requirements

  • Dry

Soil must be well drained

Yes

Light Conditions

  • Full sun
  • Partial sun

Additional Lighting Information

Kokiʻo ʻula can tolerate shade but produces more flowers in full sun.

Spacing Information

Plants should be spaced 3 to 5 feet apart. For hedges 2 1/2 to 3 feet apart. Specimen plants should be should be spaced 10 to 15 feet apart.

Tolerances

  • Drought

Soils

  • Cinder
  • Organic

Limitations

Protect kokiʻo ʻula from strong winds especially in containers. Fairly slow growing compared with other hibiscuses. [Rick Barboza, Hui Kū Maoli Ola] Will tolerate short periods of drought [2]

leaf Environmental Information

Natural Range

  • Kauaʻi

Natural Zones (Elevation in feet, Rainfall in inches)

  • 150 to 1000, 0 to 50 (Dry)
  • 1000 to 1999, 0 to 50 (Dry)

Additional Habitat Information

Kokiʻo ʻula is found in a few dry forests of eastern Kauaʻi.

leaf Special Features and Information

General Information

The large Mallow family Malvaceae contains some 2,300 species, with notables such as okra, cacao, durian, baobab, kenaf, and cotton. [3]

There are perhaps as many as 300 species worldwide in the genus Hibiscus. There are six native species of hibiscuses in Hawaiʻi and all but one are endemic.

The Hawaiian name Kokiʻo ʻula is shared by our two native red hibiscuses (Hibiscus clayi and H. kokio).

Hibiscus clayi differs from Hibiscus kokio in a few ways:

  1. Leaves of H. clayi are smooth, or occasionally toothed only near tip; H. kokio leaves are toothed from below middle to the tip (sometimes smooth).
  2. H. clayi is restricted to Kauaʻi; H. kokio is naturally found on Kauaʻi, Oʻahu, Molokaʻi, Maui and Hawaiʻi.
  3. H. clayi shrubs are generally more compact in habit or form than H. kokio, which tend to be more free forming.

Etymology

The generic name Hibiscus is derived from hibiscos, the Greek name for mallow.

In 1928, Albert W. Duvel discovered several small hibiscus trees on Kauaʻi that were damaged by cattle. He brought them into cultivation, which proved to be a new species. Isa and Otto Degener named these plants Hibiscus clayi, after the late Horace F. Clay, a horticulturalist and instructor of botany at Leeward Community College (Leeward CC) on Oʻahu. [4] A small garden with Hibiscus clayi and a small sign in his honor is on the Leeward CC campus in the front near the Biological Science Building.

Margaret James Roe, in her studies of the genus Hibiscus in Hawaii, found another species on Kauaʻi and thus named it Hibiscus newhousei, but is considered as a synonym of H. clayi. [4]

Hawaiian Name:

Kokiʻo is the name given for this species, and ʻula means red.

Early Hawaiian Use

Early Hawaiians grew both the native red and white hibiscuses near their houses for their flowers.

Modern Use

With so many flowers nearly always available, Clay's hibsicus makes a beautiful lei. [2]

Additional References

[1] Jill Coryell, Hibiscus Lady http://www.hibiscusladyhawaii.com/

[2] "Small Trees for Tropical Landscape" by Fred D. Rauch & Paul R. Weissich, page 60.

[3] http://en.wikipedia.org/wiki/Malvaceae [Accessed 10/14/09]

[4] Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status of 24 Plants from the Island of Kauai, HI.

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