Hawaii has a combination of USDA winter hardiness zones 10 to 11. Most of the islands do not dip below a minimum temperature of 40 degrees Farenheit in the winter except for the tall mountaintops, which can have freezing temperatures. Hawaii has two main seasons. Summer is from May until October when the sun is directly overhead and the temperatures are warm. Winter is where the sun is shining from the south and the temperatures are cooler. The Pacific Ocean surrounds the islands and creates a mild climate.
Ahakea (Bobea timonioides) is a rare tree native to the Hawaiian Islands that grows 30 feet tall. The leathery, green leaves are 4 to 5 inches long. The fragrant flowers are trumpet-shaped and are followed by 1/2 inch long, oval fruit. The ahakea grows in dry woods and rain forest at elevations between 800 to 1,900 feet. This tree is used as a landscape plant.
Kokio (Kokia drynarioides) is a tree 30 to 50 feet tall that spreads 15 to 20 feet wide. This deciduous tree has leathery, maple-tree shaped leaves 3 to 8 inches long. These leaves are medium green, dark green and red. The red flowers resemble hibiscus blossoms with twisted petals and blooms in the spring and summer. The flowers provide honeycreeper birds with an abundant source of nectar. This tree is drought tolerant and grows in dry, volcanic soil. Only a few kokio trees remain in their natural habitat.
Oha wai (Clermontia arborescens) is a shrubby tree that grows up to 30 feet tall. It grows a canopy 6 feet wide made up of dark green, oblong leaves that are 2 to 4 inches long. Large flowers that are greenish-white, pink and yellow appear in the summer. The petals of the oha wai curl backwards. Yellow and orange berries follow the flowers. This tree lives longer than 5 years in full sunlight. This tree is an epiphyte, which is a plant that grows on another plant. The oha wai is found on mossy tree trunks or high up in branches.
Pendant Kihi Fern
Pendant kihi fern (Adenophorus periens) is a perennial fern called palai la'au by the native Hawaiians. This fern grows draping, green fronds 4 to 12 inches long. These fronds grow on damp trees in groups. This fern only grows in the Hawaiian Islands and is threatened. The pendant kihi fern's habitat is destroyed by volcanic activity, causing a dearth of its host trees due to poisonous gasses emitted from geothermal areas.