594 A NATURALIST IN THE PACIFIC. 



NOTE 68 (page 264) 



ON SOME OF THE HAWAIIAN ENDEMIC GENERA, EXCLUDING THOSE OF 

 THE COMPOSITE AND LOBELIACE^E 



Haplostachys , Phyllostegia, and Stenogyne, all Labiate Genera. 

 Phyllostegia is not strictly peculiar to Hawaii, since out of the 1 7 species 

 enumerated in the Index. Kewensis, 15 are Hawaiian, i Tahitian, and i is 

 accredited to Unalaska (one of the Aleutian Islands). The last locality 

 appears to be an error. The species in question is P. microphylla, Benth. ; 

 and on looking up the original authority in Linncea (vi. 570, 1831), I find 

 the locality is thus given : "insula coralligena RomanzofKn," which is either one 

 of the atolls of the Paumotu Islands in about lat. 15 S. and long. 144 W., 

 or a coral island of the Marshall Group, most probably the former. ... I 

 paid some attention to the suitability of the fruits of these three Labiate 

 genera for dispersal by frugivorous birds, for which the fleshy nucules in 

 the cases of Phyllostegia and Stenogyne apparently fit them. Out of the 

 fruits of five species of Phyllostegia examined by me, the seed-coverings in 

 three species, after the removal of the fleshy covering of the nucule, were 

 too soft for the protection of the seed in a bird's stomach. Hillebrand also 

 observes (p. 347) that the nucules when dried are wrinkled, and absorb 

 moisture easily, a quality which, if true of all the species, would make the 

 distribution of the genus by birds impossible. However, in two species I 

 found the seed-coverings somewhat harder. It would seem that since 

 birds have largely ceased to disperse these plants, the soft-skinned nucules 

 would in the absence of their selective agency more frequently characterise 

 the genus. It is possible that the dry nucules of Haplostachys, which 

 according to Hillebrand are not affected by drying, represent the original 

 condition of those of Phyllostegia, and that the fleshy character has been 

 acquired in this archipelago. It will be seen in the list on page 263, that 

 Haplostachys is regarded by Gray as a section of Phyllostegia. The 

 remarks under Phyllostegia, regarding the softness of the seed-coverings 

 beneath the fleshy coat of the nucule, also apply to Stenogyne ; and Hille- 

 brand, in contrasting its fleshy nucules with the dry nucules of Haplo- 

 stachys, implies that they absorb water, which, I may remark, would render 

 them quite unfit for dispersal by frugivorous birds. 



Touchardia ( Urticacecz). According to Hillebrand, the solitary species 

 is by no means common in the group now. In 1897 I found it growing 

 abundantly some miles up the Waipio gorge, Hawaii. 



Cheirodendron (Araltacece). C. Gaudichaudii, the well-known " Olapa " 

 tree, is common in the forests of all the Hawaiian Islands between 2,000 

 and 5,000 feet ; but I noticed it occasionally at greater elevations, as on 

 the south-east slopes of Mauna Kea, where it extends to 7,000 feet. As 

 described on page 343, the " Olapa " often grows in close contact with the 

 Lehua (Metrosideros polymorpha), the two trunks appearing as one. The 



