How can I properly frame this? On O’ahu, few places have intrigued me as much as Wailupe. A lot of it has to do with its historical association with the scientific inquiry of Hawaiian biota. Some of it is because of the native assemblage the valley still retains. But I think a lot of it has to do with that same ole recurring theme here at Studia Mirabilium: Sharing the Planet. Here are some awesome native forests in a valley that Hillebrand once roamed. And it’s all right behind urban Honolulu…
Just a quick primer. William Hillebrand is one of the legendary figures in Hawaiian botany. Back in his day (1800’s) much of the scientific knowledge came from expeditions that stayed few weeks, collected biotic samples, and left. In contrast to that, Hillebrand lived in Hawai’i for about 20 years, serving as the royal physician. He was a self-taught botanist who extensively collected and surveyed the islands throughout his time here. One of his favorite collecting areas was Wailupe Valley in the Southern Ko’olau mountains. Wailupe, it seems, escape much of the deforestation from people and grazing mammals that devastated so much of the hills behind Honolulu. It is here that he helped show the world the wonder that is the Hawaiian flora.
So early on a Saturday morning, we ragtag bunch of eclectic minds and able bodies began a survey of parts of Wailupe Valley. What was the first native we came across this time?
Unsurprisingly, it’s ‘ulei (Osteomeles anthyllidifolia). Now, before I move to the next plant, let’s actually take some time to really appreciate this species. The situation is kind of hard to believe. Think of tennis in the early 2000’s. Roger Federer was dominant versus everybody except Nadal on clay. Or ace starting pitcher Tom Glavine against longtime backup catcher for the Marlins, Mike Redmond. The persistence and dominance of this species in an ecosystem long overrun by nonnatives is really something to applaud. I tip my cap to you sir, you are a darn tough out.
Humor me for a bit with this baseball analogy. In this game of World All-Star Exotics Vs. Wailupe Valley Natives, the Natives are doing their best to end the Exotics long winning streak. If ‘ulei hit a lead off double, the heart of the order is collectively spitting on that first pitch breaking ball. They’re not going to make it easy for the Exotics.
Case in point. We came across a patch absolutely dominated by lama (Diospyros sandwicensis) and lonomea (Sapindus oahuensis). The lonomea were HUGE! Check out the size of the trunk.
Mean. And the trees were quite fecund too: the gully floor was carpeted with a layer of S. oahuensis seeds with many keiki sprouting.
The forest floor also had other native seedlings germinating. Amongst all the lonomea seeds, a good number of ‘awikiwiki (Canavalia galeata) were trying to get established.
But in this mighty lonomea patch, one plant stood out.
There are papala (Charpentiera spp.) found scattered in the Southern Ko’olau mtns. But C. obovata is pretty rare. This little tree was about 7 ft tall and the only Charpentiera in sight. Keep on growing brother!
So I’m guaranteed to be impressed by random sports facts and rare native plants. But it is not just rarity. Intactness, to me, is also quite impressive.
From the Sapindus patch, we entered another incredibly intact native forest. Like Kuli’ou’ou, it had some of the same players (lama, ‘ulei) but this forest had a bunch of other conspicuous characters. The sedge behind the lama is all Carex wahuensis. In fact, C. wahuensis and Bidens sandvicensis were the dominant ground covers in this lama forest.
Maile (Alyxia stellata) was also a very conspicuous member of the forest. It was found in many spots clambering up the lama trees.
The forest itself wasn’t as invaded with christmasberry and guava as much as Kuli’ou’ou; there were many parts were it was a pure lama canopy. And we were lucky that it also held some rarer gems.
I’ve only seen keahi (Sideroxylon polynesicum) one other time. I was pretty excited to see 4-5 healthy looking plants in the lama forest.
And this plant I haven’t seen before. Granted it’s probably because I’ve blithely overlooked it! This dainty plant is Phyllanthus distichus. Notice the flowers growing below the level of the distichous leaves.
Another rarer plant was this kolomona (Senna gaudichaudii). I am actually more familiar with this plant in coastal locations, so seeing this species a some elevation was pretty neat.
We brought in Joel to close out the Kuli’ou’ou post, should we do it again? We’re up a bunch o’ runs but…why not? Let’s crush the World All-Star Exotics’ spirit. This is the very view Joel had to work with when he rediscovered Lobelia monostachya all those years back. And it’s still there on that far off rockface, hiding in plain sight. Again… what an incredible find. I may have started out the hike with a sense of history. Hillebrand, this giant of the Hawaiian conservation world may have studied the very trees we were looking at in this post! I ended feeling good that the gentlemen I was hiking with were also in the process of writing their own glorious chapter in Hawaiian Biology. Mashuri, Tim, Alex, Joel… keep on throwing those nasty strikes!
Great summary of Wailupe. This region of the southern Ko’olau mountains has been overlooked for many years. Relegated to an afterthought for most Biologist when it comes to the idea diverse native biological realms on O’ahu. The difficulty is in whether we should spread the word about this areas richness to preserve and protect it. Or should keep it to a whisper in order to arrive at the same conclusion? It is a hard thing. As Hillebrand noted the diversity, he mentioned ‘Uhi’uhi and Hauhele’ula amongst the diverse assemblage of species. Those two have always intrigued me. There is even a street named ‘Uhi’uhi in the valley. In any case, mahalo for sharing.
Glad you enjoyed it Scott. Who knows what is still in the seed bank waiting for its day in the sun 🙂