Report a known pest or a plant or animal that you suspect may be acting invasively.
Have you seen Jerusalem Thorn (Parkinsonia aculeata)?
Hawaii Early Detection Network Priority Pest for the islands of Maui and Kauai
Distinctive feathery leaves
Detail of zig-zag stems and thorns
Distinctive strip-like leaf stem
This small thorny tree (up to 7.6 m or 25 ft) thrives in the same coastal and dry areas that kiawe (Prosopis pallida) grows. Jerusalem Thorn's feathery leaves are distinctive, formed by a 25-40 cm (10-16 in) long flat spine-like tripinnate leaflet stems with 22-30 pairs of small opposite leaflets. Yellow orchid-like flowers. Seeds are in pods 5-20 cm (2-8 in) long. Seeds are green with brown or purple spots. Stems covered with thorns.
Impacts: Jerusalem Thorn is considered one of the weeds of national signifigance in Australia, covering nearly 3,100 sq miles of semi-arid to subhumid tropical areas and is considered to be a high risk species in Hawaii according to the Hawaii Weed Risk Assessment. It is not known to currently grow in Maui County, after a few plants were removed by the Maui Invasive Species Committee (MISC) (see map.) This pest has spread throughout the world as an ornamental tree and has since escaped from cultivation. Parkinsonia is fast growing, drought tolerant, and able to grow in different soil types. In Australia, Parkinsonia can form dense thorny impenetrable thickets along water courses and drainages.
Dispersal Mechanism: Jerusalem thorn seeds disperse via water courses and flood conditions It is also dispersed by animals and humans who spread the plant long distances in landscaping. If you see it anywhere else in Hawaii- let someone know!
Kiawe (Prosopis pallida):
Kiawe is the ubiquitous thorny mesquite that is found in dry and coastal areas of Hawaii. Kiawe can be differentiated by its rounded leaflet stems and yellow catkin (catterpillar-like) type flowers.
Funding and support for this project was made possible by the Hawai'i Invasive Species Council, the USDA Forest Service State and Private Forestry assistance, and University of Hawai'i-Pacific Cooperative Studies Unit.