So, I’ve been blogging here at Studia Mirabilium for almost a 1/4 of a score now. And hiking almost every weekend since I started. We’re talking a couple hundred of hikes now. But in that time, there were still major portions of O’ahu that I haven’t step foot in. Circumstance and priority may have kept me away, but I was finally able to hike the southern portion of the Wai’anae volcano. I couldn’t wait to see how different that forest would be from my usual stomping grounds. Yes, it was a whole new world for me. So I hope you will join me on this ride (minus the soma-induced flying carpet of course)…
Most of this part of the island is in the rain shadow of the Ko’olau range. The summit is much drier because of it. Geologically it is older than its larger, eastern sister and also closer to Kaua’i. All these factors played a part in shaping the forest in this part of O’ahu. But enough background… what was the first native plant we came across?
Not too surprisingly for me, it was that indomitable native sedge Carex wahuensis. As we’ve seen in Wailupe, C. wahuensis can be a dominant ground cover in dry-mesic forests. But the next plant through me for a loop.
This was a first for me. I had never seen hu’ahu’ako (Rumex albescens) in the wild before. Found on the older islands of Nihoa and Kaua’i; on O’ahu it is only really known from the Wai’anae mountains. In this part of the forest, it is still a common element of the understorey.
Another plant that is fairly well known but one that I haven’t come across in the wild much is ‘ala’ala wai nui wahine (Plectranthus parviflorus). I’ve seen it plenty of times in cultivation, but still nice to come across a healthy patch.
I didn’t know if it was just me, but I thought the Koa (Acacia koa) looked a little different. There actually weren’t too many koa trees that we saw but the phyllodes seemed much bigger. But I don’t know… maybe I was still shaking off the soma.
While there was not much koa, this forest seems to still be dominated by several different forms of ‘ohia lehua (Metrosideros spp).
One form seems to be some sort of Metrosideros “B” while the other one is… uh, some kinda hybrid (cop out alert!).
It surprised me, but another plant we saw a lot of was Pilo (Coprosma spp).
Normally in the Ko’olau range, I’ve only sporadically come across Coprosma patches and usually in wet summit areas. Here, pilo seems to be a dominant player in the mesic Wai’anae forest.
Another completely brand new species for me is this native violet or pamakani (Viola chamissoniana var. tracheliifolia). Skottsberg treated this as a separate taxa (V. tracheliifolia) but it was subsequently lumped into V. chamissoniana. I tend to follow a certain school of thought for the nomenclature but where it officially stands, like many things, is debatable.
Regardless of the name, pamakani is very common in this forest. We saw it in dense colonies all along the trail.
Yet another new species that I saw on the trail for the first time was hulumoa (Exocarpus gaudichaudii). Man, am I sure I do a lot of botanical surveying? 🙂 This is quite a strange looking tree because it doesn’t really have leaves. The green stem ends do most of the photosynthesis for the plant. Unfortunately this special plant is getting rarer and rare on O’ahu.
This handsome devil is a Panaunau (Lobelia yuccoides). This species is only found on Kaua’i and here in the Wai’anae mountains. So many Wai’anae specific plants have Kaua’i ties. It was quite a strange experience for me to travel just to the other side of the island and yet see such a different mix of plants.
Let’s close this post with ichogenus! I loved dinosaurs growing up and one of the places I wanted to visit was Pennsylvania because of all the Triassic dinosaur footprints. Scientist named the tridactyl theropod footprints there Grallator. One translation is stilt walker. But we don’t actually have fossils of the dinosaur that made those footprints eons ago. Luckily, here in Hawai’i that name is associated with something much more tangible.
Yup, I went for a strange 225 million year old footprint tangent just to say that I took my first photo of a Happy-faced Spider (Theridion grallator)! Huxley would probably not be impressed. (I’m better than an Epsilon, I swear!) But looking at the single pair of elongated legs, you can see where the species epithet might have come from.
That about wraps it up. What an amazing forest. I hope this post gives you a glimpse into the diversity in this part of O’ahu. It seems the more we dig, the more natural wonders of Hawai’i we still manage to find.