85 



PRECINCTIVE FLORA OF THE IVAIANAE MOUN- 

 TAINS, OAHU. 



An Annotated Reference List of Seventy Species and. 

 Varieties. 



By Vaughan MacCaughey. 



The island of Oahu is made up of two mountain masses, the 

 remnants of former gigantic volcanic domes, designated by the 

 native names — Waianaes and Koolaus. Although now forming 

 a single island, there is abundant evidence, both geological and 

 biologic, to indicate that these masses at one time in the history 

 of the Oahu region formed two distinct islands. The Waianae 

 Range is very much older than the Koolaus, and undoubtedly 

 existed as an island long before the Koolau dome emerged from 

 the sea. For more extended accounts of the very interesting 

 geologic history of the Waianaes, see Hitchcock, Hawaii and Its 

 Volcanoes, and Bryan, Evidences of the Deep Submergence of 

 the Waianaes, in Thrum's Annual for 1916. 



As a result of these geological mutations and the topographic 

 and climatic changes that have developed therefrom, there are 

 many species of plants that are highly precinctive on Oahu. Of 

 these a notable number are confined almost exclusively to certain 

 portions of the Waianaes. The author, in connection with 

 botanical instruction at the College of Hawaii, has had occasion 

 to make numerous field excursions into the Waianae Range, and 

 to take parties of college students into these mountains. The 

 following list has been prepared for purposes of convenient ref- 

 erence, and has proven of value in connection with this field 

 work. Unless otherwise noted the species are endemic : 



1. Alectryon macrococcus,^2id\\<i-/'Mahoe." Soap-tree Fami- 

 ly ; Kauai to Maui ; xerophytic ; on Oahu only in Makaha Valley ; 

 medium tree. 



2. Alphitonia excclsa, Reiss ; "Kauila." Tree (medium to 

 large). Buckthorn Family; rare; all islands; on Oahu, Wai- 

 anaes only ; xerophytic ; species occurs throughout Australasia 

 and Polynesia. 



3. Alsinidendron trinerve, Mann. Pink Family; summit and 

 western slope of Kaala only ; erect undershrub ; sepals greenish- 

 red. 



4. Bobea Hbokeri, Hillebd. ; "Ahakea." Madder Family; 

 Oahu only, rare, Wailupe and Makaleha ; tall shrub or small 

 tree ; flowers greenish-yellow. 



5. Breiveria Menziesii, Benth & Hook. Convolvulus Family; 

 Oahu to Maui ; rare ; on Oahu only Kaala and \\'ailupe ; a 

 diffuse woody twiner ; flowers greenish. 



6. Campylotheca micrantha, Cassin. Composite Family; spe- 



