UH gardening gurus set invasive-species classes

Hawaii gardeners have the advantage of a year-round growing season that allows us to pick up plants any time of year and add them to our backyard collection. And local garden centers carry an abundance of ornamental shrubs, trees and herbs from which to choose.

The University of Hawaii Cooperative Extension Service wants to help home gardeners to be knowledgeable when choosing plant material. The UH Master Gardeners on Oahu have teamed up with the Hawaii Invasive Species Council to provide classes and demonstrations to the public. (See the Star-Advertiser’s Home & Garden calendar for class listings.)

What is an invasive species? Technically, according to HISC, an invasive species is an alien species — plant, animal, or microbe transported by humans to a location outside its native range — whose introduction has caused or is likely to cause economic or environmental harm or harm to human health.

Basically, foreign plant material that propagates at warp speed and those seeds or plant parts that can travel long distances to naturally forested areas are termed invasive. These plants often demonstrate rapid and aggressive growth, production of numerous seeds that are spread easily by wind, wing or water, and the ability to grow under many different soil and climatic conditions.

What is the impact of invasive species? It’s the plants whose “keiki” reach the natural forested areas that take the largest toll on our native species and ecosystems. They threaten native plant habitats, reducing the number of native plants and affecting plant biodiversity, as well as the insect biodiversity that depends on those plants.

Deadly Nightshades

By Glenn I. Teves, County Extension Agent, UH College of Tropical Agriculture

The recent deaths of horses, mules and cattle on the island believed to be caused by consuming poisonous plants mixed in hay brings attention to the many poisonous plants we have on the island. The most obvious suspect is one of the deadly nightshades, Jimson Weed or Datura stramonium, seen throughout Ho`olehua. It is known by many names, including Stink Weed, Devil’s Apple, Thorn Apple, and Moonflower. This plant resembles the Apple of Peru, Nycandra physalodes, a common weed in Ho`olehua, and one in which animals eat without any negative effects. It has a similar flower and leaf shape, which could cause animals to eat Jimson Weed by mistake.

A member of the tomato family, or Solanaceae, the poisonous nightshades caused edible members of this family, especially tomatoes, to be viewed for generations with apprehension because people thought they were poisonous. Jimson weed or Jamestown Weed has a reputation that goes back centuries. Its scientific name, stramonium, means ‘mad nightshade’ due to its reputation for making people delirious or mad.

Its common name originated from Jamestown, Virginia where, in 1676, the British were sent to crush a rebellion, called the Bacon’s Rebellion. The British made a boiled salad from the Jimson Weed leaves, and were delirious for 11 days. When they came to their senses, they couldn’t remember a thing.