It was my goal in 2007 to photograph the five (5) species that make up ohia lehua. Ohia lehua has always inspired me. Their distinctive flowers, dainty leaf rosettes and gnarled branches add much color, form, and character to the native forest.
Ohia Lehua Species Found on
Metrosideros polymorpha Hawaii, Maui, Oahu, Kauai, Molokai, Lanai
Metrosideros tremuloides Oahu – Koolau Mtns – Nuuanu, Manoa, Waahila
Metrosideros rugosa Oahu – Koolau Mtns – Kalihi, Palolo
Metrosideros macropus Oahu – Koolau Mtns – Aiea, Poamoho
Metrosideros waialeale Kauai – Mount Waialeale, Kanaele Bog
“Polymorpha” means “many forms” after the myriad of forms the plant can take. Ohia lehua can be tall straight trees in dry forests, stunted shrubs in montane bogs, or giant “walking lehua” in rainforests. Polymorpha is endemic to the Hawaiian Islands and has adapted itself to almost every ecological zone from sea level to 7,000 feet elevation.
It is believed that ohia lehua evolved from an ancestral polymorpha from New Zealand which found its way to the Hawaiian islands in the distant past. It then adapted and evolved itself to local conditions.
The pom-pom shaped blossom is actually a cluster of flowers that have long stamens and pistils. Red is by far the most common color but lehua come in a broad spectrum of red-orange-yellow hues including crimson, salmon, peach, and lemon. Some flowers have multiple colors. Oral tradition speaks of white lehua and people claim to see it, but science has not validated its existence. White lehua is the “big foot” of Hawaii.
Polymorpha has short petioles (leaf stems) that enable the leaves to form little rosettes. Young leaf rosettes, known as “liko” in Hawaiian are used in leis for their attractive shape and color. Lehua blossoms are also a favorite flower in leis.
Some forms of ohia lehua have evolved far away enough from polymorpha for botanists to declare them a distinct species–they have classified the various forms of ohia lehua into 5 species.
Many thanks to The Nature Conservancy for letting me visit their their Kona Hema Preserve on the Big Island to photograph the photo of polymorpha above.
Tremuloides or ahihi has pointed leaves, long red leaf stems (petioles), and its leaves do not form rosettes. Slender branches of ahihi often extend themselves outward and assume a weeping form. The flower buds of ahihi often do not grow in tight clusters together–the buds are spread apart. As a result, the flowers cannot achieve the classic pom-pom shape–the pom-pom has “holes”. Ahihi is endemic to the island of Oahu. This photo was taken from the Awaawaloa Trail that leads to the Koolau Summit from Waahila State Park.
Rugosa or Lehua Papa has round pointed leaves that are deeply furrowed. Lehua papa has short leaf stems (petioles) that form tight rosettes. The entire progression of leaf growth is shown in this photo–from leaf buds (muo) to young leaves (liko) to dark green leaves with prominent furrows. Lehua papa is also known for fine bronze hairs on the backside of its leaves. Lehua Papa is endemic to the island of Oahu. This photo was taken on the Koolau Summit Ridge overlooking Kaau Crater (and Palolo Valley) and Maunawili.
Macropus has long broad pointed leaves that do not form rosettes. It also has curious leafy growths that start out as leaf bud sheaths. In this photo of macropus, you can see the unusual curly leafy growths on the new light green leaves to the right of the yellow lehua. All the macropus flowers I have seen are yellow but I according to the Manual of Flowering Plants of Hawaii, they can be red too. Macropus is endemic to the island of Oahu. This photo was taken at along the Aiea Ridge trail that leads to the Koolau Summit.
Waialeale has long pointed leaves and long petioles (leaf stems) that do not form rosettes. Waialeale is endemic to Kauai. It lives at Mount Waialeale which averages 460 inches of rain a year and on the mountain ridges overlooking Kalaheo. This photo was taken above Kalaheo between the Alexander Reservoir and Kanaele Bog on Kauai.
Many thanks to The Nature Conservancy for taking me to Kanaele Bog and to the National Tropical Botanical Garden for letting me stay at their facilities and confirming that the specimen is waialeale.