The narrow, oblong leaves are somewhat leathery and range in size from 3 1/2 to 10 inches long and 3/4 to 2 3/4 inches wide. The veins are fairly prominent on the upper surface of the leaf and the lower surface is covered with white or pale brown hairs. The edges of the leaves are smooth and slightly rolled under. The ends of the leafs are pointed.

Pittosporum hosmeri has male and female flowers on separate plants so plants of both sexes are required for seed to form. The flower clusters contain 9 to 12 flowers and form either directly on the branches of the plant or from the base of the leaf stem. The cream-colored flowers are tubular and 1/4 to 1/2 inch long. The flowers are fragrant at night.

This Pittosporum is closely related to P. hawaiiense and, according to Wagner, they apparently hybridize when grown together. However, Culliney and Koebele observed that the fruits of P. hosmeri are ripe in the winter while P. hawaiiense fruits in the summer. (Culliney 1999; Lamb 1981; Wagner 1999; Weissich 1995)

Woolliams reports that green fruit will often open if stored in a plastic bag. Koob noted that he has only has success with ripe fruit; he has been unsuccessful with both seeds from green fruit and with stored seeds. Culliney and Koebele found that viable seeds cannot be obtained from green fruit even when mature. Only fresh seed from newly opened ripe fruit germinated. Their procedure is to extract the seeds from the capsules and immerse them in a room temperature solution of 9 parts water to 1 part household bleach for 1/2 hour. After the seeds are removed from the bleach solution, they are soaked in tap water for a day using just enough water to cover the seeds. The seeds are sown on the surface of wet vermiculite in sterilized containers. The containers must have good drainage. The seeds are covered with a 1 inch layer of dampened green sphagnum moss. Culliney and Koebele found that Pittosporum seeds took many months to sprout. Koob reports sowing the seeds on the surface of peat-based soil-less potting mix which is kept moist, but not wet. In his experience, the first seeds take about 9 months to germinate, but all germinate within a month or so after the first ones.

Obata reports that Pittosporum species set very few seeds and that many seeds lack embryos. Artificial pollination did not result in additional viable seed. (Culliney 1999; Koob 2002; Lamb 1981; Obata 1997a; Obata 1997b; Wagner 1999; Woolliams 1976)

However, Adams obtained 100% rooting for the 3 cuttings he tried. These were 6 inch long semi-soft tip cuttings. They were treated with Greenlight talc containing 0.1% IBA. He used a rooting mixture of 1 part peat to 4 parts. The cuttings were rooted in a propagation structure with a clear Lexan roof using a misting system. The mist cycle was 30-45 seconds every 30 minutes. It took six weeks or more for the cuttings to root. (Adams 2003; Criley 1998; Criley 1999)

Criley, Richard A. 1998. Propagation of indigenous and endemic ornamental Hawaiian plants. Combined Proceedings of the International Plant Propagators' Society 48:669-674.

Criley, Richard A. 1999. Aloha Hawai'i. American Nurseryman 190 (3):50-61.

Culliney, John L., and Bruce P. Koebele. 1999. A native Hawaiian garden: how to grow and care for island plants. Honolulu: University of Hawai'i Press. p. 61-64.

Koob, Gregory A. 2002. "Ho'awa seed." E-mail. Posted 9 June 2002 to hiplants-l@hawaii.edu.

Lamb, Samuel H. 1981. Native trees and shrubs of the Hawaiian Islands. Santa Fe, New Mexico: Sunstone Press. p. 43-44.

Obata, John K. 1997a. Common native Hawaiian plants worthy of cultivation. Newsletter of the Hawaiian Botanical Society 36 (3/4):74.

Obata, John K. 1997b. Growing native Hawaiian plants. Newsletter of the Hawaiian Botanical Society 36 (3/4):75-76.

Wagner, Warren L., Darrel R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawai'i, rev. ed. 2 vols., Bishop Museum Special Publication 97. Honolulu: University of Hawaii Press and Bishop Museum Press. p. 1044-1045.

Weissich, Paul R. 1995. Hawaiian native plants in the landscape. Combined Proceedings International Plant Propagators' Society 44:332-335.

Woolliams, Keith R. 1976. The propagation of Hawaiian endangered species. NATO Conference Series. I, Ecology 1:73-83.