192 



doubt of their identity. I should say the specimen which 

 you sent us as P. Whitei is just a meagre condition of P. 

 decom'positum. The latter is a rather polymorphic species, 

 but whether the forms which may be distinguished within it 

 represent stable races or indicate merely a wide amplitude of 

 fluctuation or a considerable degree of plasticity I do not 

 venture to say. R. Brown's original matches very well with 

 McGillivray's specimen from Port Curtis and comes very near 

 the form described by Domin as var. acuminatissimum , which 

 latter has, however, slightly larger spikelets and somewhat 

 coarser panicle-branches. Brown's type has blades up to 

 4 mm. wide; most of the remainder of our material have 

 broader leaves and fatter stems. Your specimen and the 

 smaller piece of Andrews' collection have shorter, narrower, 

 and less rigid leaves, but the big piece of Andrews has the 

 blade up to 9 mm. wide. As to Domin's var. utile, I doubt 

 whether it can be distinguished from the typical form with 

 broader leaves. We have not been able to confirm the char- 

 acters he indicates. His var. scaherrimum, and Bailey's var. 

 tenuioi' may stand as such for the present. Typical P. decom- 

 positum seems to range all over Australia. The specimens 

 enumerated in the Flora Australiensis under P. decornpositum 

 also include some referable to P. paludosrini , Roxb. This is 

 how I name them as far as I have seen them : — 



''P. paludosum, Roxb. — Victoria River, F. Mueller 

 (certain specimens only) ; King Creek, Bowman; Archer 

 Lagoon, Leiikhart (Leichhardt? ). 



"P. decompositum, R. Br. typicum. — Gulf of Carpen- 

 taria, E. Bromn; Port Curtis, McGillivray ; Macleay River, 

 Beckler; Lake Eyre, A7idrews; W. Australia, Brummond 43; 

 Murchison River, Oldfi.eld. 



"P. decompositum var. acuminatissimum, Dom. — Vic- 

 toria River, Mueller. 



"P. decompositum var. scaherrimum, Dom. — Cygnet 

 Bay, Cunningham.'^ 



To Dr. Stapf's remarks I would only add that many of 

 our northern specimens have the lower panicle-branches 

 solitary and alternate, and only some of the upper ones 

 clustered. 



^Eragrostis inajor. Host. Pinnaroo (per H. W. 

 Andrew). Said to have appeared in the district in 1915, and 

 to be relished by cattle. 



ChENOPODI ACEAE . 



Arthrocnemum halocnemoides, Nees. Salt swamps near 

 Dry Creek (J. M. B.) ; Swan River, W.A. (D. A. Herbert). 



