where Metrosideros polymorplia (Oliia leliua) got the upper hand and now forms 

 nearly pure stands, with perhaps a few other trees, like Straussia and Suttonia, 

 on the more recent lava flows which intersect the mixed forests. This, however, 

 is due to the wonderful adaptability of the Oliia to nearly any environment 

 trad to its quicker growth, while the trees of the mixed lower forests are ex- 

 tremely slow growing and their seeds usually do not germinate before one or 

 two years, or perhaps much longer, after which the two cotyledons remain for 

 another year before a third leaf appears. Trees of these mixed forests have 

 practically no epiphytes and only one or two lianes are present, Embelia sp., 

 whose huge, rope-like stems are entangled in the tops of the trees, having a thick- 

 ness of several inches near the ground, on which they are twisted like the coil of a 

 rope before ascending the trees. This giant Embelia has only been observed so 

 far by the writer in the kipuka Puaulu, near the volcano on Hawaii. 



Caesalpinia bonducella is very common on the lava fields, and the writer met 

 with huge plants whose rope-like stems climbed the tallest trees, forming also an 

 impenetrable mass on the ground, very treacherous on account of their recurved 

 sharp thorns and very spiny seed pods. Besides these lianes, two parasites are 

 exceedingly common, one being the Hawaiian mistletoe, Viscum articulatum, 

 which at that locality infests mainly the ebenaceous Maba sandwicensis, while 

 the leafless parasite, Cassytha filiformis, with its thousands of thread-like, yellow 

 ftems, covers the tops of trees (usually Plectronia odor at a), which in due time 

 succumb to this pest. (See plate VIII.) 



Strange to say, these mixed forests have hardly any native undergrowth, 

 with the exception of a few ferns and grasses, though in late years lantana and 

 guava have driven out the few native plants which formed this undergrowth. 

 In dry forests of normal conditions a few composites thrive, such as Lipochaeta, 

 and a menispermaceous vine, CoccuUis Ferrandianus, and a species of the cucur- 

 bitaceous genus Sicyos. Some of the trees belonging to the mixed or dry forests, 

 as the handsome Pelea multiflora, Alectryon macrococcus and Hibiscadelphus, 

 but mainly the former, are covered with a species of lichen which gives the trees 

 a mournful appearance and is really injurious to them. This particular species 

 (Usnea australis) does not infest all trees, but only certain species, mainly Pelea 

 multiflora, in the dry forest of Auahi on the southern slope of Haleakala. 



Though it is said that the more conspicuous lichens are common on unhealthy 

 trees, rather than on thrifty ones, nevertheless when they do occur in such quan- 

 tities as on some of the trees of the mixed forests, they must interfere with the 

 functions of the bark. It also may be said that nowhere is the lichen flora richer 

 in species than in the mixed or dry forest of the lower zone. 



On Kauai, the dry or mixed forest zone has almost entirely disappeared and 

 only a few trees can still be found. Most of the land has "been cleared for sugar 

 cane fields up to an elevation of nearly 2000 feet; above Makaweli only little is 

 left, while above Kekaha only grass land spreads up to an elevation of nearly 

 3000 feet. 



19 



