Trematocarpus

The Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species. The six genera can be broadly separated based on growth habit: Clermontia are typically branched shrubs or small trees, up to 7 metres (23 ft) tall, with fleshy fruits; Cyanea and Delissea are typically unbranched or branching only at the base, with a cluster of relatively broad leaves at the apex and fleshy fruits; Lobelia and Trematolobelia have long thin leaves down a single, non-woody stem and capsular fruits with wind-dispersed seeds; and the peculiar Brighamia have a short, thick stem with a dense cluster of broad leaves, elongate white flowers, and capsular fruits. The Hawaiian lobelioids are a group of flowering plants in the bellflower family, Campanulaceae, all of which are endemic to the Hawaiian Islands. This is the largest plant radiation in the Hawaiian Islands, and indeed the largest on any island archipelago, with over 125 species. The six genera can be broadly separated based on growth habit: Clermontia are typically branched shrubs or small trees, up to 7 metres (23 ft) tall, with fleshy fruits; Cyanea and Delissea are typically unbranched or branching only at the base, with a cluster of relatively broad leaves at the apex and fleshy fruits; Lobelia and Trematolobelia have long thin leaves down a single, non-woody stem and capsular fruits with wind-dispersed seeds; and the peculiar Brighamia have a short, thick stem with a dense cluster of broad leaves, elongate white flowers, and capsular fruits. The group contains morphologically divergent species, and was long thought to have derived from at least three introductions: one for Lobelia and Trematolobelia, one for Brighamia, and one for Clermontia, Cyanea, and Delissea. Based on recent DNA sequence evidence (Givnish et al., 1996, 2008) it now believed that all are derived from a single introduction. This was likely a Lobelia-like species that arrived about 13 million years ago, when Gardner Pinnacles and French Frigate Shoals were high islands and long before the current main islands existed. Many species have beautiful and spectacular flowers, especially those in Lobelia and Trematolobelia. Unfortunately, they are also highly vulnerable to feeding by feral ungulates such as feral pigs; the stems are only partly woody, and contain few defenses against herbivory. The bark contains a milky (but apparently non-poisonous) latex, and is often chewed by rats and pigs. Seedlings are also vulnerable to disturbance by pig digging, and in areas with high densities of pigs it is not uncommon to find the only lobelioids being epiphytic on larger trees or on fallen logs. Brighamia is quite unlike the other genera, with a succulent stem and long, thin, tubular flowers. It was long thought to have been the result of a separate introduction, and its unique combination of characters made it difficult to place. These characters are the result of adaptation to growing on cliffs and pollination by the endemic Hawaiian hawkmoth, Manduca blackburni. This moth is now itself listed as endangered, surviving mainly on the southern slopes of Maui, well away from where Brighamia live. Some pollination may be done by closely related alien hawkmoths such as the five-spotted hawkmoth (M. quinquemaculata) and pink-spotted hawkmoth (Agrius cingulata). Despite their inaccessible habitat on cliffs, Brighamia are sometimes hand-pollinated by botanists to ensure seed set. Both species are now extremely rare. The genus is named in honour of the first director of the Bernice P. Bishop Museum, William Tufts Brigham. Brighamia species † species believed to be extinct* species is listed as endangered Lobelia is a cosmopolitan genus of over 350 species, including common ornamentals. However, many lobelioid genera are derived from it and it is highly paraphyletic. The Hawaiian species are divided into two sections (Galeatella, the giant lobelias of montane bogs, and Revolutella, the smaller lobelias of rocky crests and interior rock walls), based on flower color and other characters. Like Brighamia and Trematolobelia, the fruit of Lobelia is a dry capsule. These species are probably the closest in appearance to the original Hawaiian colonist. Lobelia species † species believed to be extinct* species is listed Endangered