DDIOKPHISM OF EESTIACE^. 37 



crispatus, E. Br.''' The type-specimens of this plant are in 

 the Banksian herbarium at the British Museum, where I 

 have had the opportunity of examining Brown's types of Res- 

 tiacecB. Brown's specimens inchide plants of two different 

 aspects, some with relatively elongate (one to two feet) uu- 

 hranched stems usually sterile, and with sheaths of two forms, 

 those at the base near the rhizome being relatively short and 

 tightly wrapped around the stem, those at the upper portion being 

 longer and spreading away fi'om the stem near the apex. The 

 other form of stem is much branched above the middle, where it 

 divides into a wealth of intricate, curved, rigid, needle-like 

 branchlets, the terminal ones of which, contrary to what generally 

 (but not universally) happens in these much-branched stems, bear 

 spikelets. The sheaths on the unbranched portion of the stem are, 

 relatively speaking, lightly wrai^ped around the stem. So different 

 in aspect are the two forms of stem just described, that Mr. Ben- 

 tham, in looking over these very specimens, affixed a note to the 

 form with unbranched stem and lax sheaths to this effect, — 

 ''These do not belong here." On subsequently examining these 

 specimens myself I lighted on one in which both forms of stem, 

 with both forms of sheath, sprang from one and the same rhizome. 

 A fragment of this specimen, sufficient to indicate the different 

 appearance of the stems and sheaths, is given at tab. 194, ii., 

 where fig. 1 represents a portion of the plant with its dimorphic 

 stems, the unbranched one being shorn, in the drawing, of a con- 

 siderable proportion of its proper height. The tight sheaths at the 

 base of the stem, as contrasted with the longer, looser ones in the 

 upper part, are plainly shown. On the fertile branched stem, the 

 sheaths are seen to be all of them shorter and closer than on the 

 unbranched barren stem. Figs. 2 and 3 show sheaths of the two 

 forms detached. For the full description of the plant I must refer 

 to the forthcoming supplement to the ' Prodromus ;' but I may 

 add that the differences above noted are independent of sex, occur- 

 ing on both male and female plants, and that the flutings and 

 other markings which often afford good specific characters in this 

 genus are identical in the two forms. I have spoken of the 

 character afforded by the sheaths as being in some senses in- 

 trinsically unimportant, but in others it appears to me that they 

 are far from being so ; and the particular instance which has sug- 

 gested this note tempts one to speculate on the origin of varieties, 

 the differentiation of sexual and of s^Decific forms, and other matters, 

 a temx^tation which the limits of space and the patience of the 

 reader induce me forthwith to resist. , 



* Kestio crispatus, Pt. Br. Prodr. 246 ; Kunth Ennm. iii, 418; Benth. Flor. 

 Austral, vii, 2-25. Mast, in DeCand., Suites au Prodrom. i., 271, ined; Calo- 

 rophus cris2)atus, Nees in PL Preiss. ii. 07. 



