| Pritchardia (pritch-AHR-dee-ah) |
Powerline Trail, Kauai, Hawaii. "Fruit Showing Apical Stigmatic Remains." Photo by Dr. John Dransfield, Royal Botanic Gardens, Kew/Palmweb.
Habitat and DistributionHawaii. Wet forest on the northeastern slope of the Waialeale massif and the Makaleha
It is a medium-sized palm from 6–8 m (20–26 ft) tall, with palmate (fan-shaped) leaves about 1 m (3.3 ft) long. The fruit is produced in dense clusters, each fruit green, pear-shaped, 4 cm (1.6 in) long and 2.5 cm (0.98 in) in diameter. May reach 10 m tall; proximal margins of petiole with only a few fibers; leaf blade flat, divided 1/3, abaxial surface completely covered with lepidia, appearing silvery grayish white, segment tips stiff; inflorescences composed of 1-5 panicles, shorter than petioles in flower and fruit, panicle branched to 2 orders, rachillae clothed with scurfy indumentum in flower, glabrous or nearly so in fruit, rachillae and flowers viscous; fruits 19-40 x 12-21 mm, ellipsoid to obovoid.(Hodel, D. 2007)/Palmweb.
Its leaf blades completely covered abaxially with lepidia, inflorescences shorter than the petioles, and especially the viscous panicles and flowers, which alone are diagnostic, readily distinguish Pritchardia viscosa.(Hodel, D. 2007)/Palmweb.
Pritchardia viscosa is a medium palm, 6 to 13 m height; the stem gray-brown with vertical striations, 16 to 21 cm diameter breast high. It has an open crown with about 10 to 20 leaves. It is the only member of the genus with flowers, buds (calyx and corolla) covered in a thick viscous as if varnished. The rachillae (flower bearing branches) are glabrous and viscous. There are one to three panicles; the peduncular bracts are wooly, dense, tan; and the inflorescence are shorter than the crown; the lower surface of the leaf blades are covered with a silvery-gray, lepidote; the ripe fruit are fibrous, black, and elliptical-pyriform, 40 x 25 mm. (virtualherbarium.org)
"this is an extremely rare palm-only 4 individuals left in the wild on Hawaii, and also extremely rare in cultivation. It has large, wedge-shaped flat perfect leaves only barely split at the tips and the undersides are a luminscent coppery silver. Very ornamental if you can find the seed ... someday seedlings may be for sale if they can get the plants to reproduce". (Geoff Stein).
This palm prefers a sunny, well drained, and moist location.
"Apply a complete palm fertilizer with minor elements as directed on label. Be certain that sufficient magnesium and potassium is present in the fertilizer component. This is especially critical for loulus in pots. Magnesium and potassium deficiencies are two of the most serious nutritional disorders in palms. The deficiencies are characterized by bright yellowing (chlorotic) on leaf edges or streaking or the entire fronds yellowing. This can be difficult to reverse. Applications of Epsom salt, or magnesium sulfate (MgSO4), is good but does not last and is usually washed out of the soil in rainy periods. There are some very good slow release fertilizer spikes made for especially for palms on the market which contain a good balance of minor elements with magnesium and potassium. [2,3] Potted or younger loulu planted in the ground appreciate a foliar feeding of kelp or fish emulsion and Epsom salt monthly or bi-monthly. [David Eickhoff, Native Plants Hawaiʻi." (Encyclopedia of Life curator Dr. David Eickhoff)
Loulu are prone to leaf rollers, red spider mites and sugar cane borers. Rats will eat its fruit. (Encyclopedia of Life curator Dr. David Eickhoff)
Pritchardia viscosa is an easy to grow palm but not often available for the landscape. Pritchardia viscosa vary in shape. Specimens raised in dry and/or infertile soils tend to be smaller in stature with smaller leaves. Light also affects the plant's form while those grown in full sun are more compact. This palm prefers a sunny, well drained, and moist location. Growth rate: It is a slow growing, short stocky palm. Soil: It likes organic soil, but is adaptable to clay and loam both slightly alkaline and acidic. Good drainage is also important. Fertilization: Need a perfect fertilizer diet including all micro nutrients and trace elements or slow release fertilizer. Micro-nutrient deficiencies are occasional problems. If it doesn't get enough Mn and Fe (Iron), the leaves take on a rather unhealthy yellow colour. Micro-nutrient deficiencies only show up on soil with a high pH. Fertilize often for faster growth. Water Requirements: Needs regular water, do not let dry out between waterings. however it does not want to sit in continually wet, mucky soil. The roots and lower trunk can rot if soil is kept too moist. Light: Prefers full sun but will tolerate half day sun. Hardiness: It is adapted to tropical and subtropical climates, young plants are more cold sensitive. Maintenance: Remove dead fronds and spent fruiting stalks for a clean landscape appearance. Fronds can be left on the palm to form a skirt for natural settings. Palms recycle nutrients from dead or dying fronds and use them for healthier fronds. Palms only have a set number of new leaves that can sprout and grow per year and removing fronds will not increase that number. If you cut off more than what will grow annually, you could be left with a pretty bare and bald palm. Pest & Disease: Mealybugs and whiteflies underneath the leaves can present problems at times if not kept in check. A generous spray of water can wash them off. Ornamental: It is cultivated as an ornamental tree, and planted in gardens and parks in tropical and sub-tropical climates either as a single specimen or in groups. Culture in containers is possible although growth rates are slower. A bright patio will provide an excellent environment for young specimens which can eventually be planted in a sunny location. (llifle.com)
Comments and Curiosities
Conservation: In situ management has been conducted by the land managers, the Department of Land and Natural Resources, Division of Forestry and Wildlife (DLNR-DOFAW) with a fenced exclosure around two individuals protecting them from grazing animals and pigs, metal rat guards also circle their stems. Ex situ collections with known wild origins are maintained and protected by the DLNR-DOFAW, botanic gardens on Kauai and Oahu. Pritchardia viscosa is recognized by the Center for Plant Conservation (CPC), which provides educational awareness. Recovery plans have been thoroughly researched and produced for P. viscosa by the United States Fish and Wildlife Service (USFWS). Recommended management strategies include: protection of in situ populations, adding rat baiting, invasive weed management and long-rang monitoring; establish new wild populations; establish effective ex situ populations; collaborate to accomplish conservation biology research; adhere to invasive weeds, pest management, and quarantine procedures. Establish reliable protocols for seed storage, including effective seed banking as a conservation tool. (virtualherbarium.org)
Etymology: Pritchardia name is dedicated to William Thomas Pritchard (1829-1907), British official stationed in Fiji in the 19th Century, British counsul in Fiji, adventurer, and author of Polynesian Reminiscences in 1866. The epithet is Latin for “viscous”, an allusion to the texture of the inflorescences. (Bill Chang) Critically Endangered; Restricted to the windward side of Kauai Island. Only two wild trees were known until recently, when two more were discovered; one of which has been harvested. (ICUN Redlist 1998.)
Threats to Survival: Predation of P. viscosa seeds occurs from introduced rats (Rattus rattus, R. exulans, and R. norvegicus). Introduced vertebrates such as deer (Odocoileus hemionus columbianus), goats (Capra hircus), and pigs (Sus scrofa) also reduce P. viscosa seedlings by grazing and uprooting them. Invasive weeds such as grasses (Paspalum conjugatum) and guava (Psidium guajava, P. cattleianum) can form weed mats and out-compete young palm seedlings. Seed harvesting and poaching by humans also occurs. One individual had permanent damage to its stem made by a person wearing pole-climbing spikes. A seedling in the population area was removed, after being observed by the author for over four years and an intentional, shovel-made hole in the ground remained. Pests and disease are a constant threat. Existing threats include the two-spotted leaf hopper (Sophonia rufofascia), and Phytophthora, as well as serious potential threats if introduced, such as the West Indian sugarcane borer (Metamasius hemipterus) or Lethal Yellowing disease and its known vector the palm cixiid (Myndus crudus). (virtualherbarium.org)
Pritchardia viscosa (Loʻulu or Stickybud Pritchardia) is an extremely rare endangered species of Pritchardia palm that is endemic to the Hawaiian island of Kauaʻi.
Like the related Nihoa Fan Palm (P. remota), it is susceptible to extinction by a single catastrophic event because of its wild population of four individuals. It is threatened by introduced rats, which eat the seeds. It has been cultivated to a moderate extent, but is exceptionally limited in its habitat.
"The trunk of this species grows to 20 feet in height and has a diameter of 8 inches; it has one of the more slender trunks for the genus. The leaf crown is open and nearly spherical with 40 inch-wide semi-circular leaves whose segments extend 1 foot into the blade. They are stiff and on-pendent, even in older leaves. Leaf color is glossy and light, grassy green above and beautiful silvery green beneath. In 1992, Hurricane Iniki caused a decline in the population. The current threat to the species in its natural habitat is seed predation by rats, pigs and humans." (Bill Chang)
- Glossary of Palm Terms
- MODERN BOTANICAL LATIN
- "Just To Be Clear"
Phonetic spelling of Latin names by edric.
Special thanks to Geoff Stein, (Palmbob) for his hundreds of photos.
Special thanks to Palmweb.org, Dr. John Dransfield, Dr. Bill Baker & team, for their volumes of information and photos.
Glossary of Palm Terms; Based on the glossary in Dransfield, J., N.W. Uhl, C.B. Asmussen-Lange, W.J. Baker, M.M. Harley & C.E. Lewis. 2008. Genera Palmarum - Evolution and Classification of the Palms. Royal Botanic Gardens, Kew. All images copyright of the artists and photographers (see images for credits).
Hodel, D. 2007.
Many Special Thanks to Ed Vaile for his long hours of tireless editing and numerous contributions.