Plant Profile
Kadua acuminata
Au, Pilo
Main Plant Information
Genus
Kadua
Species
acuminata
Hawaiian Names with Diacritics
- Au
- Pilo
Hawaiian Names
- Au
- Pilo
Synonyms
- Hedyotis acuminata
- Kadua grandis
- Kadua grandis f. pubituba
- Kadua kaalae
- Kadua petiolata
- Kadua petiolata var. ovalifolia
Plant Characteristics
Distribution Status
Endemic
Endangered Species Status
No Status
Plant Form / Growth Habit
- Sprawling Shrub
- Shrub
Mature Size, Height (in feet)
- Shrub, Small, 2 to 6
- Shrub, Medium, 6 to 10
- Shrub, Tall, Greater than 10
Mature Size, Width
Variable from a few feet to over 8 feet.
Life Span
Long lived (Greater than 5 years)
Landscape Uses
- Accent
- Container
Source of Fragrance
- Flowers
- Leaves
Additional Fragrance Information
Au does not have a pleasant fragrance. The leaves produce a foetid, or foul smell, when bruised or crushed. Flowers have a similar smell but weaker.
Plant Produces Flowers
Yes
Flower Characteristics
Flower Type
Not Showy
Flower Colors
- Greenish-White
- White
- Yellow
Additional Flower Color Information
Flowers are variable in color ranging from yellowish-green, occasionally green and apparently rarely (Kauaʻi) greenish-white.
Leaf Characteristics
Plant texture
- Fine
- Medium
Leaf Colors
- Dark Green
Pests and Diseases
Additional Pest & Disease Information
In cultivation, mealybugs, scale and thrips can plague the plants if not monitored. [David Eickhoff, Native Plants Hawaiʻi]
Aphids are also said to be pests.
Growth Requirements
Fertilizer
Foliar feed plants monthly or every other month with a dilution of fish or kelp emulsion. The plants also respond well to monthly foliar and/or soil feedings, at half or one-third recommended strength, of a slightly acidic fertilizer such as Miracle-Gro Miracid . [David Eickhoff, Native Plants Hawaiʻi]
Water Requirements
- Moist
Soil must be well drained
Yes
Light Conditions
- Partial sun
Soils
- Cinder
- Organic
Environmental Information
Natural Range
- Kauaʻi
- Oʻahu
- Molokaʻi
- Lānaʻi
- Maui
- Hawaiʻi
Natural Zones (Elevation in feet, Rainfall in inches)
- 150 to 1000, 50 to 100 (Mesic)
- 150 to 1000, Greater than 100 (Wet)
- 1000 to 1999, 50 to 100 (Mesic)
- 1000 to 1999, Greater than 100 (Wet)
- 2000 to 2999, 50 to 100 (Mesic)
- 2000 to 2999, Greater than 100 (Wet)
Habitat
- Terrestrial
Additional Habitat Information
Au is found on all the Main Islands in mesic to occasionally wet forests from 295 to 2625.
Special Features and Information
General Information
Au is a member of the very large Coffee family or Rubiaceae of more than 13,000 species throughout the world. The family is well represented in the islands with about 60 species.
The genus Kadua is comprised of 30 species total in the Pacific region and most are represented in the Hawaiian Archipelago with 25 endemic species. Recently a revision of the genus Hedyotis was made and the genus Kadua is accepted for all Hedyotis in the Hawaiian Islands. [1]
Etymology
Kadua is the oldest generic name for these species and is named in memory of M. Kadua, a native of Ulea, who sailed with Otto von Kotzebue (1787-1846), Baltic German navigator in Russian service, with the purpose of collecting plants. [1,2]
The specific epithet acuminata is from the Latin acuminatus meaning “with a long, narrow and pointed tip” [3] in reference to the long, narrow leaves of this species.
Background Information
This species is very closely related and similar in foliage to the rare kamapuaʻa ( Kadua fluviatilis ). The two will easily hybridize if they are grown together. [David Eickhoff, Native Plants Hawaiʻi]
Early Hawaiian Use
No known use.
Modern Use
There appear to be few plants in cultivation of this common and easy to grow native shrub.
Additional References
[1] “Resurrection of Genus Kadua for Hedyotidinae (Rubiaceae)” by Edward E. Terrell, page 819, 831.
[2] “A General System of Gardening and Botany, Vol. 3,” by George Don, page 533.
[3] “The Names of Plants” by David Gledhill, page 36.