134 HORN EXPEDITION— BOTANY. 



Thus Paliii Creek, at the time of our visit, contained a slight flow of fresh water, 

 whilst the waterholes in the channel of the River Fiuke, in the Glen of Palms, 

 was undrinkahle ; the latter circumstance may explain the rare occurrence of the 

 fan-palm in the Glen of Palms, though it is in near proximity to the main colony 

 at the former place. 



(2) Frost. The main flowering period follows on that of the chief precipita- 

 tion of rain, which usually tikes place in January or February ; so that, by the 

 time the arboreous and shrubby vegetation has regained its vigour and the 

 flowering condition reached, the season of nightly frosts has been entered upon.* 

 However, before this has come to pass the annual vegetation has for the most 

 part run its course. Though the effects of frost were not general, yet in the case 

 of the following species (Cassia veniisfa, Santa/itin acKtiiinafiiiii, Clerodendron 

 Jloridundiim), growing in open places they were most marked, not only the flowering 

 buds killed, but the foliage presented a withered appearance. To the same cau.se 

 I attribute the not infrequent absence of mature seeds, either by checking the 

 perfection of the se.xual organs or by killing-off those insects (and certainly at the 

 time of our visit insect life was feebly represented) which are the agents of 

 pollinisation. 



Some of the Lar.ipintine plants may be regarded as connecting links between 

 the Autochthonian and Euronotian floras, and in some species to indicate the 

 horizontal plane of divergence from the primitive stock. Among restricted species 

 Xaiithorrliaa Thorntoiii, though occupying an insular position, is the centre of a 

 semi-circumferential distribution of the genus, from the south-west by south to east 

 and north-east of the continent. The same remark is applicable to Coininerconia, 

 spp., Anthobohis exocarpoides^ Bceckea polystemonea, Actinotus Scfnvarzii and 

 Macrozamia Macdonnelli. 



Hibherlia glabcrrima stands alone as an extralimital species in the section 

 Hemihibbertia, otherwi.se Autochthonian. It ranges from Queensland through 

 the Larapintine area (its metropolis) to Mount Olga and Everard Range. 

 Gastrolobium grandifloriini is the only extra- Autochthonian species of this large 

 genus, and radiates from the Larapintine region to Attack Creek and Newcastle 

 Waters on the north, to the adjacent parts of Queensland and New Houtli Wales, 

 and to the Eremian portion of West Australia. Jirachysenia Cluimbersii is a link 

 between the home; of the genus in West Australia an<l the northern stations of a 



'k The minimum thermometric readings were almost always below freezing point, and the greatest cold regis- 

 tered was 15 deg. F. 



