A few weeks back, I had the pleasure of attending Don Hodel’s talk on the native Loulu palms (Pritchardia spp.) found here in Hawai’i. It was highly informative. Mostly, Dr. Hodel focused on the key distinctions between various species. The very next week, as if on cue, the L.I.C.H. Native Plant Initiative was having their Pritchardia hike. Armed with this new found knowledge, I joined them on a hike for Loulus above La’ie.
The La’ie trail is restricted access. Luckily, the permits are easily obtained at Hawaii Reserves, Inc. A couple of other notes about the trail. It seems the standard procedure is to park on Puohaili St. by the La’ie Field. The trail itself is not overly strenuous but it is a longer one. I would say it is about 4 hours roundtrip. And that’s if you don’t stop to look at the native flora like our group!
Like so many trails, the La’ie trail starts in highly degraded habitat with nary a native in sight. Some of the first native plants that are conspicuous on the trail are the lowland Akias (Wikstroemia degeneri/vaccinifolia). Even then it is still mere pockets of native flora. These Akias haven’t been setting fruit for a few years now. Perhaps there was a crash in its pollinator’s populations. Whatever the case, these plants aren’t regenerating anymore.
Further along on the trail is a clearing filled with a nice diversity of native trees. Ahakea (Bobea elatior), Maua (Xylosma hawaiiense), Kalia (Elaeocarpus bifidus) and Koa (Acacia koa) all towered over the uluhe. The highlight of the clearing was the nice, big Holei (Ochrosia compta).
We’ve seen this lovely native dogbane before, in the hills above Pupukea. As you can see in the middle of the picture, this tree was coming into fruit.
Another species that I’ve seen previously in the Pupukea area was this Ho’awa. Pittosporum cauliflorum is found in dry to mesic areas of O’ahu. Unlike Pupukea, where P. cauliflorum is rather common, this is the only one I noticed.
We also saw several Hulumoa (Korthalsella remyana) on various individuals of Lama (Diospyros sandwicensis). This species does have other plant hosts, but so far I’ve only seen it on Lama. Most of the time, you come across the more common species (Korthalsella complanata). That species has much flatter internodes, unlike the almost tube-like form seen here.
Here, we came across the burn site. Sometime in July 2008 a fire had started, burning a few acres. The fire burned for a few hours until rains helped firefighters contain it. While unfortunate that many old native trees were lost, it is interesting to see the succession.
Instead of opportunistic weeds establishing themselves and overrunning the place, natives have come back in force as the dominant plants. Here you can see the 2 species leading the charge: Pala’a (Sphenomeris chinesis) and Uki (Machaerina mariscoides).
To make this feel good story even better, B.Y.U. has taken the opportunity to help the native forest reestablish itself by outplanting several different species of plants. We didn’t stop long, but I saw little Naupakas, Iliahis, as well as Koas like pictured above. You can watch their efforts here. Good luck with everything, may the trees grow strong and fast!
Just past the burn site was one of our targets for the day.
This is no mere Pritchardia martii; it’s P. kahukuensis! This species of loulu has much smaller fruit that P. martii. The crown is also typically this spherical shape. Compare the crown to the very first picture in this post, a P. martii from further up on the trail. It might be a little hard to see on this picture, but the next one should clearly show how strange this individual is…
… it’s growing sideways out of the hillside! The trail actually passes directly underneath the crown. Awesome, awesome plant.
Past the kahukuensis, we came across the other native loulu found on the trail, Pritchardia martii. There is an area where the 2 species of loulu are growing in close proximity of each other. After a while, you don’t see P. kahukuensis anymore, it’s all P. martii up to the summit.
P. martii is the most common of the different Loulus on O’ahu. It is also the most variable. In general though, martii have large fruit, short infloresences and a more hemispherical looking crown.
Tetraplasandra oahuensis is also common along the upper portions of the trail. There were many individuals that were very easy to see.
Another easy to see plant was this Ala’a (Pouteria sandwicensis). Feeling the leaves of Ala’a is something I like to do, the upper surface is so smooth to the touch. Some individuals have more pubescence than others on the lower surface. Indeed, the ones from Lana’i are these brown, hairy things! But back to this island…
We also saw a different species of Ho’awa on the trail. Way above the P. cauliflorum in a wetter area, was this guy. This is Pittosporum glabrum. The P. glabrum that I have seen all seem to have this much smaller leaf size, compared to say P. cauliflorum and P. flocculosum.
A highlight for me was something I had actually missed on the way up. As we started walking back down to our cars, we saw this little mint (Phyllostegia glabra). It’s a species that I had not seen before. The eroded bank had dozens of them popping up.
One thing that I appreciate about hiking in the northern Koolaus is seeing the different composition of the native forest compared to my usual haunts back near town. To see plants endemic to this area, or perhaps just in different densities, makes hiking the La’ie trail is a pleasure for any native plant enthusiast.