> 4 



TO THE FLORA OF AUSTRALIA. 161 



coll : N,W. Coast ; I)e Boidey), with one small exception to be noticed 

 soon, agrees with Brown's description, as also with material at Kow authen- 

 ticated in Bentham's handwriting a.^ tlie writer's conception o£ T, Il(jstrii\ 

 Flower and fruit a[)art; the two specie:^ [ir^drix :ind occidenfalis) are wry 

 like ont! another, the flowers of occithntaVis being much smaller and tlic 

 fruits clearly different. As contrasted with similar organs of T, JTystrir, 

 the following points may be mentioned \—Pedicelli l"5-2'5 cm. long. Flares 

 pansi 2'5 cm, diam. Sepala lineari-lanceolata, 8 mm. long. Petala obovatii, 

 13 mm. b)ng. Frnctus snmmum modo 2 cm. diain. ; horum sjumc inter 

 sesG parum inser[uales, sc. longiores ^ mm. broviores 5 mm, long. 



Beutham's 7'. Ilfjstvlc may thus safely be considered to be conspecific 

 with Brown's 1\ occidentalism iha sliglit and not af nil obtrusive inequality 

 in the spines on the fruit having evidently been overlooked l)y l?rown when 

 drawing up his (h.\scription. 



The J\ Hystrix referred to by Mueller * as collected by Giles at Lake 

 Amadeus may perlinps be the true plant of Brown, as he notes its havino* 

 petals sometimes an inch long; but tlie material cannot have been in iM*po 

 fruit, or Mueller would not have consideied it (/. 6'.) as conspecific with a 

 Dampier Archipelago {i.e. N.W, Coast) jdant of Hughan and Walcott, 

 which is almost certainly T, oecidentalis. That 3Iueller did not know the 

 difference between Ifystrix and occidenfalis is clear from his glviiK-f "West 

 Soutli, and North Australia for the distribution of T, Ilystrix^ which, so far 

 as known, is a Central Australian desert species. 



Two very small specimens at Kew from Central Anstralia (Gosse 230 and 

 Bahbage 7) may perhaps belong to 7'. Ilystrix^ but tliey are in flower only. 



The Australian species of Trihulus anil Exitrihidas may be tabulated as 

 follows : — 



L Cocci of fruit winged mid witliout pricldes. 



Glabrous or nearly so. Cocci smooth between the 



wing-s T. platyptermj Renth. 



Hirsute. Cocci reticulate between the wingg T, himdiiSy Benth. 



Cocci of fruit win|>cd and provided with conical prickh^s. 



Fruit promiuentlj angled T. 7nacrocarpus^ F, Muelb 



Fruit rounded T, Forrestii, F. Muel!. 



II. Wingless cocci provided with prickles. 



Prickles few, short, more or less conical. 



Annual. Flowers small T, terrestrisy Linn, 



Perennial. Flowers 3*6-4 cm. in diameter T, cistoideSj Linn. 



Annual Flowers upwards of 2 cm. in diameter , T, rammculijlorus, 

 Prickles numerous, subulate or conico-subulate, [F, Muell. 



Flowers large. Fruit nearly 3^J cm. across T. Ilijstrix, R. Br. 



Flowers of medium size. Fruit up to 2 cm. across 7". occidentalism B. Br, 



* Frag, Phyt. Austral, xi. p. 30. 



t Sec. Cens, Austral. PI. p. '22. 



2 



.^ 



