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genus Hetcrotoma; Grammatotheca occurs both in South Africa and Australia 

 with two species, one in each continent. 



The herbaceous genus Pratia is found in South America and the neighboring 

 islands down to the Magellan Strait, New Zealand, Australia and tropical Asia 

 (one species only in India and Java). 



Isotoma to which our Hawaiian genus Briglunnia is very closely related is 

 composed of eight species of which six are peculiar to Australia, one to the 

 West Indies and one to the Society Islands. 



Tlie genus Lobelia proper which jjossesses about two hundred species has the 

 widest distribution. It occurs in the tropical as well as temperate regions of 

 the world with the exception of Central and Eastern Europe and AVestern jVsia. 

 The remaining genera are more or less dwarfed herbs, usually annuals, to which 

 category belong also the genera Prntin. Ileteroioma, and Isotoma. Of tlie re- 

 maining genera three inhabit North America and one the ilediterranean region, 

 besides occurring in North America and Soutli Africa. 



The Lobelioideae may be conveniently dividetl into two main groups, one 

 with baccate and the other with capsular fruits. It is remarkalile to find that 

 of the Hawaiian genera four have true baccate fruits. Outside of these islands 

 there remain only the genera Ccntropogon in South America and Pratia, with 

 most of its species South American with true baccate fruits. All the rest of 

 the genera belonging to the Lobelioideae have capsular fruits. Of these we 

 possess three, Trematolobelia and Brigliamia, which are peculiar to these Islands, 

 and the genus Lobelia proper, Brigliamia with fruits of a semi-baccate nature or 

 rather fruits with a somewhat fleshy thin exocarp. From this we may infer 

 that the bulk of the Hawaiian Lobelioideae the four genera with baccate fruits, 

 are related to South American species especially fo the genus Centropogon, but 

 of that later. 



The remarkable fact remains that the extensive island groups of the Western 

 Pacific as for example Fiji and Samoa are void of J^obelioideae and this is 

 also true of the Malayan region, the Philippines and New Guinea. The only 

 Pacific islands which do possess Lobelioideae are Tahiti, Raiatea, and Rarotonga, 

 hut each island possesses only one or two species, while the Hawaiian Islands, ^o 

 far as they have been explored, have yielded one hundred forty-nine species, 

 varieties and forms, belonging to seven genera, six of which are endemic. 



ORIGIN OF THE HAWAIIAN LOBELIOIDEAE. 



To the seven genera of Lejbelioideae existing in these islands, we must at- 

 tribute at least three different ancestors, which again had their origin in as 

 many different and remote regions. We will divide the IIa\vaiian genera there- 

 fore into three groups and discuss tlicir relationship with existing foreign 

 species. The most interesting of these three groups are without doubt those 

 with baccate fruits so numerous in the Hawaiian Islands. As has been pointed 

 out in the last part of the previous chapter, the Hawaiian genera Vgaiua. Cler- 

 niontia, RoUandia and Delixsea are unquestionably of American affinity and find 

 their present closest relative in the genus Ccntropogon. That tlieir age is enor- 

 mous and that they form with the Compositae the oldest element in our flora may 

 be .judged from their iinmerous species and their distriliuticui over the whole 



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