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By Jim Bishop, for Let's Talk Plants! January 2022.


A Variegated Pandanus utilis, AKA Screw pine, overlooking Turtle Bay on the north shore of Oahu.

In mid-December 2021 we did a quick trip to Oahu trying to stay ahead of possible travel shutdowns before the Omicron COVID variant became more widespread. Our original plan was to visit Costa Rica, but due to difficulties with cancelled flights and problems with international travel, we changed plans and went with a small group of friends to Oahu. We stayed for 5 nights at the east end of Kapiolani Beach, just east of Waikiki.

Moon over the Pacific Ocean and Kapiolani Beach. iPhone night mode takes a long exposure which blurs the coconut palms.

Many people overlook Oahu when visiting Hawaii and head to one of the other islands. However, Oahu is usually easier to fly to from San Diego and offers many similar sites.

On day one of our visit Scott and I set out on our own to visit gardens and hike.

Koko Crater Botanical Garden

The garden, as the name suggests, is located in an ancient volcanic crater on the eastern side of Oahu. It is free to visit. The cactus garden was created by Charles M. Wills. It features plants from many dry tropical regions of the world, but is best known for is collection of succulents and cacti. We had the garden mostly to ourselves.

Looking ready for the holidays, bloom of Euphorbia punicea native to Jamaica and Cuba.

Looking ready for the holidays, bloom of Euphorbia punicea native to Jamaica and Cuba.

Cactus with the crater rim up above.
A cactus forest with cycads native to Central America.
A particularly wavy cactus and Scott.
There are a lot of epiphytic cacti that have naturalized in Hawaii, but this one gave the tree a surreal Van Gogh effect.
Pachypodiums grow very well in lava soils and look like something out of a Dr. Seuss children's book.
South African Gardenia volkensii fruits.
In Africa, the fruits are eaten by monkeys, elephants and other animals which disperse the seeds.

Ho'omaluhia Botanical Garden

Our next stop was the 400 acre Ho'omaluhia Botanical Garden on the eastern, windward side of Oahu. It is large drive-through park with stops to see plants from various locations around the world. It backs up against some impressive eroded volcanic cliffs.

Roadway winding through the lush forest at the base of volcanic cliffs.
One of many Heliconias in one section of the park.
There were many colors of Ixora planted in one area.

This variegated Crinum asiaticum really caught my eye.

The red trunks of these Cyrtostachys renda, sealing wax palms, stood out against the deep greens of the jungle.

The stuff dreams of Hawaii are made of

The stunning foliage of Cordyline fruticosa, Ti plant, is made even better when in bloom.

This variegated Pandanus gets huge looking a lot like an overgrown bromeliad, but is in a different unrelated plant family of its own, Pandanaceae.

Manoa Falls

Our final stop of the day was the trail to Manoa Falls. It is located just above a suburb of Honolulu. You follow a trail through a dense forest of mostly non-Hawaiian plants to a view of the 150 tall falls.

A shipping container used for a bridge to cross the creek leads you into the deep and lush forest. It also provides a semi-dry spot to get out of the frequent rain showers.

Jurassic Park sized ferns lined the creek along the trail.
Bird's nest ferns and other epiphytes cover many of the trunks of trees.
Our destination, Manoa Falls.
An irresistible photo stop on the way back.
Fractals of a very large palm frond.

Much of the forest is being swallowed by Thunbergia grandiflora.

An unusual color of a philodendron bloom.

Cactus Garden at Kapi'olani Community College

One day on our visit we walked around Diamond head and then up to the top. Across the road near the entrance to the road into the crater is a garden full of some of the best examples of cactus, agaves and euphorbias. I've visited it twice in the past and always look forward to checking in on it. There are a lot of succulent plants that don't like even the little bit of cold and rain we sometimes get in a San Diego winter, so it is great to see these specimens growing in the well drained lava soil.

A nice stand of Pachypodium lamerei with swollen bases. I grow this plant in my garden, but they aren't nearly as fat...yet.

Interesting thorn patterns on the trunk of Alluaudia procera, or Madagascar ocotillo, This plant is easy to grow in frost free locations in San Diego.

Another species of Alluaudia with an interesting leaf pattern, perhaps humbertii.

Looking all the world like a giant caudiciform Euphorbia, this plant is actually in the passion fruit family, Adenia globosa.

A nice large Euphorbia taking on a tree-like form.

I have a much smaller version of this Madagascarian Euphorbia stenoclada in my garden. It is fast growing and like a giant coil of barbwire.

I also have a much, much smaller version of this crassilated form of Euphorbia lactea. A friend gave me a cutting of it last summer. It rooted quickly and grew over 6 inches taller this year.

White form of Euphorbia lactea.

While I was away, my plant in front of the house blew over in a wind and rain storm.

I've had this plant for several years. I've only been successful growing it in full sun under the eaves in front of the house. Even so, it hates being wet and cold in the winter and usually suffers from some cold damage in the warmest winter spot I have. It also has grown quite quickly and been repotted 3 times, receives a heavy annual trim and was due again for one soon. However, it blew over in the mid-December wind storm and had to be trimmed to be able to upright it. Somehow it landed without breaking any pots, but it did smash an agave.

Photo of same plant above after being trimmed and uprighted.

Miscellaneous Photos on Oahu

Plumeria pudica

Most plumerias are dormant and out of bloom at this time of year in Hawaii. However, Plumeria pudica, with its wide spoon-ended leaves and white flowers was in bloom in many places on the island. Unfortunately, it has no fragrance.

Hibiscus tiliaceus, Hau Tree

Another frequently seen plant on the island is Hibiscus tiliaceus, commonly called the Hau Tree. The Hau Tree restaurant was located in our hotel and has the best Avocado toast in the world, but that's another story. This small tree with yellow flowers frequently grows along the beach or in waterways. It is found throughout the South Pacific islands, but it is uncertain whether it is naturally occurring or was brought by the Polynesians to the Hawaiian Islands.

The flowers last only one day. In the 1960s, my grandparents had two of these trees in their backyard in Florida. My grandfather had a stick with a spike on the end that he used daily to pick up the fallen leaves and blossoms.

Close up of Ravenala madagascariensism, Traveler's palm.

Recreation of the Osaka Byodo-in Temple.

The Byodo-in Buddhist temple is a 1968 recreation of the Osaka temple set against the volcanic cliffs in Kahaluu and backed by a large stand of Cook pines, Araucaria columnaris. Wherever grown the tree is known for leaning towards the equator. However, Hawaii being in the tropics, the lean is barely noticeable, unlike the trees in Southern California.

Of course, what trip to Hawaii would be complete without a photo of a Hibiscus?


Past President, Jim Bishop, is the current publicity chairperson on the Board of the San Diego Horticultural Society and he was the 2019-2020 SDHS Horticulturist of theYear among many, many other things.


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