I hiked with some friends up the Bowman Trail to the summit of Kahuauli, hiked along the Koolau Summit Ridge to Tripler Ridge and then dropped down Moanalua Middle Ridge to exit out Moanalua Valley.
The Bowman – Moanalua Middle Ridge hike is about 12-1/2 miles long — 6 miles to the summit of Puu Kahuauli, nearly 1-1/2 miles along the edge of the Koolau Mountains, and then 5 miles to descend into Moanalua Valley.
Our adventure started at basketball court at Kahili Elementary School in Kalihi Valley where we climbed up side of the mountain dominated invasive iron wood and strawberry guava trees. August Smith and Drew Erickson climb up a rock face with a commanding view of the residential neighborhoods in lower Kalihi Valley as we make the heart-pounding climb to gain the ridge top.
After making our way up the dirt road to reach the trail on top the ridge we saw many strawberry guava, both yellow and red along the trail. We could not resist feasting on yellow strawberry guava, whose fruits are larger, sweeter and less acidic than their red counterparts.
Cloud cover shaded us from the full-brunt of the sun as we hiked up the ridge for 6 miles which undulates up and down as it climbs 2,400 feet climb to reach Puu Kahuauli, the 2,740 feet peak overlooking Kaikihi Valley on the leeward side of the Koolau Mountains and Kaneohe on the windward side.
The ridge top provided a commanding view of upper Kalihi Valley as we climbed to the summit. All along the way we could see many patches of dead rosy apples trees, which were infected and killed by a rust that is killing these trees throughout the island.
When we neared the Koolau Summit, we could peer over to the other side of the island. Red ohia lehua (Metrosideros polymorpha) flowers enhance this view of the three peaks of Mount Olomana visible through a low point in the mountains.
While climbing the distinctive knob to reach the summit, we came across many hapuu tree ferns (Cibotium sp.) which thrive in wet areas along the summit.
The summit of Kahuauli is home to a unique cloud forest dominated by ohia lehua trees (Metrosideros polymorpha) covered with a profuse growth of mosses and ferns. The summit of Kahuauli is often covered in clouds — during my previous 6 hikes to the top of Kahuauli, the summit was enveloped in a thick mist.
While other peaks along the Koolau Mountains have cloud forests as well, the forest at Kahuauli is one of the best examples of moss covered ohia trees. The trees at Kahuauli are considerably larger are more profusely covered with mosses and epiphytic ferns than at most other localities along the Koolau Summit.
When we reached the very top of Kahuauli, we were treated to panoramic views of windward Oahu. Well over 2,000 feet below we could see the curve of H-3 and Likelike Highways with Kaneohe Bay and Mokapu Peninsula on the coast. We could also see lush green Hoomaluhia Botanical Garden with its man-made reservoir and the windward landmark of Mount Olomana far in the distance.
Our plan was to turn west (left) along the Koolau Summit Ridge to Tripler Ridge and then to drop down into Moanalua Valley by way of Moanalua Middle Ridge. As we made our way along the very edge of the Koolau Mountains, low hanging clouds hovered just above and sometimes shrouded the very tops of the peaks.
When we reached Tripler Ridge, we came across one of several electrical towers that transport electricity to the windward side of the island. As we made our way along the edge, we were thrilled to stumble on a rare find.
Growing right along the edge was a rare endemic plant — Lobelia hypoleuca — in bloom with blue flowers! While the plant can attain a height of 10 feet, this plant was much smaller. With the flower stalk, the plant was no more than 3 feet high. One of the distinctive features of the plant is that the underside of its leaves are white. Lobelia hypoleuca is not on the endangered list but is by no means common.
The stalk is timed to flower over a period of several weeks with a new handful of flowers opening every few days starting from the bottom and working its way up the stalk. We were lucky to find it when it had just started to bloom. The flowers attracted a predatory insect that waited on the underside of a flower waiting for something to land. We also saw a small drosophila fly that wandered about the flowers.
Although there was only one flower stalk on this plant, Lobelia hypoleuca can produce multiple flower stalks. This rare lobelia also grows on Kauai and there is considerable variation in the color and form of the flowers.
After admiring the flowers for quite some time, we continued along the summit ridge until we reached Moanalua Middle Ridge where we dropped down into Moanalua Valley. As we descended into Moanalua Valley we reflected on our fun-filled trek along the very edge of the Koolau Mountains and our great fortune seeing Lobelia hypoleuca in bloom. What a great hike!
A monographic study of the Hawaiian species of the tribe Lobelioideae family, By Joseph Francis Charles Rock, Bernice Pauahi Bishop Museum of Ethnology and Natural History, 1919
Hawaiian Lobelioids, Wikipedia
Native Hawaiian Plants, Department of Botany, University of Hawaii