Rare native plants

[Les C]

Just wanted to share that I was fortunate to help with the planting of seedlings of Ka'u Silversword, Argyroxiphium kauense, aka Mauna Loa Silversword, in the upper Kahuku area of the Nat'l Park this past week. The seeds were collected from remaining plants on Mauna Loa and germinated in a nursery in Volcano. For my effort, I was allowed to be in a beautiful section of the Island's rainforest at over 6000 ft. I was hoping to see one of the beautiful native forest birds, the 'Akepa, but was too involved in the planting to spend enough time looking for birds. The five species of silversword are endemic to Hawai'i. Four of the five species are found on Maui, two are found on the Big Island. The species that grows on Mauna Kea is Argyroxiphium sandwicense sandwicense, or Mauna Kea silversword, Hawaiian name: 'Ahinahina. This is a trinomial, indicating a subspecies. The other subspecies, A. s. macrocephalum, is the Haleakala Silversword. The other species found (one "formerly" on Maui are 'Eke Silversword, A. calliginis; and two Greenswords, A. grayanum, and the though to be extinct, A. virescens. Some of these species only flower once after 5 or 10 to 15 years, then dies! Not one of your great candidates for a native Hawaiian garden. That, and the fact that they grow at >6000 ft.

While on this service trip, I learned that the native plants sold by Home Depot are raised by a nursery on O'ahu. I've come to realize that the Brighamia insignis, a rare lobelia endemic to Kaua'i that was for sale at Home Depot last year, really makes no sense being sold on the Big Island. It might be a nitpicky point, but where endemism is a factor, paying attention to the island of endemism is important.

[For those who don't know, the word, "endemic" refers to a organism that only occurs in one location; it's usually a geographically isolated area, like an island.]

Edited by - Les C on 08/11/2007 19:37:13

[Mitzi M]

Wow, Les that's awesome that you got to help plant silverswordlings...You know, I went to the Home Despot and saw those native plants as well. A while ago I read something about the nursery on Oahu that got the contract with Wal-Mart and the Despot...It sounded so cool - like they were making these plants available (and more popular) for the regular folk. I liked the clever descriptive signs with each kind of plant letting you know it's origin, status and care. But...then I noticed the bugs...millions and millions of pest insects on virtually every native plant, including mealy bugs (plant and root), scale, whiteflies, aphids and maybe a fungus(?) on one type of plant that caused blackish spots and wilt. Yikes! It really brings up a lot of issues. I worry about plants from other islands bringing pests and diseases. I read something about a mamane disease that started this way and the possibility of spreading ohia rust. Also, if there are related plants already here on our island, there is the possibility that introduced relatives may interbreed and effect the wild gene pool. This is a big concern with the native Lo'ulu Palms as they are capable of crossbreeding if planted within 100 feet. Many of the more common nursery bred species are from Moloka'i, like P. hillebrandii - It would be a real shame to jeapordize our tiny endangered populations of P.affinis, P. beccariana etc. Maybe some species from other islands might be ok to grow here, especially if there are no simlar species represented on this island... I have to admit I have a pet 'Ihi (Portulaca molokiniensis) that lives in a pot on my lanai, far from any portulacas native here.

Aloha,
Mitzi

Uluhe Design
Native Landscape Design
uluhedesign@yahoo.com

[Les C]

At first, after reading your comment about the insect pests on the native plants, I wondered if there was any quarantine check between islands. But I recalled that at the Hawaiian Conservation Conference a few weeks back in Honolulu, the one and only entomologist who works for the State Plant Quarantine decried the fact that he and one other staffer are the only people available to screen incoming plants and ID potential insect pests. I don't think they have the bandwidth to even think about interisland shipments. (Which begs a question about the Superferry!)

Mitzi, your post reminded me of other interesting things that were the subjects of several symposia at the conference:
- Erythrina gall wasp that are decimating Wiliwili trees. This is the stuff of a best-selling mystery. This wasp traveled from the Island of Mauritius, east of Madagascar, across the Indian Ocean to India, through Southeast Asia, the South Pacific Islands, to Hawai'i, in one year! That was compared to the speed of a virus rather than an insect pest.

- 'Ohia rust, previously referred to as guava rust and eucalyptus rust, has so far not been having too much of an impact on the three native trees on which it's been found. The non-native rose apple has been the most affected.

- Also presented on were Brown Tree snakes, Imported Red Fire Ants, and Yellowjackets arriving on Christmas trees.

[ArtM]

This talk about habitat restoration by reintroducing endemic species and removing invasive ones really gets my juices going. I'm big on taking care of my own land here in California by removing broom and my current nemesis, acacia. Wish I was on the Big Island to help out!

I'm a member of the Nature Conservancy, so I knew about the Kahuku addition to VNP very early on and I was rooting for it the whole time. Just wish I could have finagled a visit last time I was on-island. Also tried to get to see some of the private palm gardens that I read about in Hana Hou, to no avail.

I noticed with interest that the silverswords were germinated in Volcano, our favorite place on the island (well, so far anyway). Would they thrive there as well or is it too low and wet (and maybe warm)?

Art M

[Les C]

quote:

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I noticed with interest that the silverswords were germinated in Volcano, our favorite place on the island (well, so far anyway). Would they thrive there as well or is it too low and wet (and maybe warm)?

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As I understand, they took cuttings from the wild plants, propagated them and to produce seed plants. So, this was like captive breeding in birds. They also collected seeds from the wild plants, several of which species, flower once after 5 to 15 years and dies! The seeds are germinated in greenhouses under controlled conditions. I don't think they would grow at the 4000' elevation otherwise. The extant wild plants and outplantings are all at or above 6000'. The different species have different requirements, some need more xeric conditions, some need mesic to humic, i.e., bogs.

Art, do you have Yellow Star Thistle where you are? In the Santa Cruz Mtns., where we lived, Scotch Broom was spreading our way, but the star thistle was everywhere, including in the open space preserves. I remember buying star thistle honey from a beehive operator in San Jose some 20 years before. Little did we know that those bees were helping to spread this weed.

[ArtM]

quote:

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Art, do you have Yellow Star Thistle where you are? In the Santa Cruz Mtns.,

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Les, I am in the Santa Cruz Mtns! (All my life, actually!)

Fortunately, I don't have a star thistle problem, but I do have the rattlesnake grass. Of the invasives, I'll take rattlesnake grass over star thistles, broom, and acacias. Star thistle makes great honey and that's about the only good thing I can say about it.

I'm seeing more and more acacias where ever I look on Hwy 17. I don't think it's getting the attention it deserves, like the broom and ivy.

The stuff I'm dealing with grows six feet per year, stump cultures like crazy, manufactures seeds by the millions, broadcasts them hundreds of feet somehow, and creates dense monoculture thickets.

Too bad about the silverswords not doing well in Volcano, but I'm not surprised. Can't really picture silverswords along side hapu`u!

Art M