376 CLXXiii, GEAMiNBiB. (BamlusecB, Gamble.) [Arundinaria. 



first time the true characters of the two types of sheath and blade that occur in 

 Bambuseis, and which do not obtain, so far as I know, in any other tribe of grasses. 

 In a communication which Mr. Mitford has been good enough to make to me on this 

 subject, he has formulated his views as follows, and has kindly allowed me to 

 introduce them here. 



" The sheath is an organ playing so important a part in the life of the Bamboo 

 that it deserves something more than a cursory notice. In the grasses generally the 

 sheath is regarded by botanists as taking the place of the petiole of the leaf. It 

 happens, however, that the leaves of most Bamboos — indeed of all 'the hardy Bamboos 

 — have a distinct continuation of the midrib of the leaf attaching it to the sheath 

 and articulated, which continuation might perhaps be correctly termed a petiolule. 

 The Bamboos, as it appears, bear sheaths of two types. There is first of all the 

 series of sheaths which, borne one on each node and wrapped tiglitly round the 

 culm or branch, as the case may be, protect it during growth. This form of sheath , 

 is divided or split transversely into two members, the ligule and the limbns or blade, 

 the latter being what I would term a pseudophyll, or false leaf, sessile, lacking both 

 midrib and petiole, varying in size in tlie different species, but always the first part 

 to wither and disappear. In some Bamboos — those of the Phyllostachys group — 

 this sheath falls away as soon as branching takes place ; in others, of the Arundinaria 

 group, it remains, and having guarded the tender growth of the parent culm or 

 branch it springs aside with the young branches or branchlets, devoting the remainder 

 of its life to their protection until they can stand alone. 



" Then there is the second form of sheath bearing a true leaf with petiole and 

 midrib. This is the form assumed by the two, three, or four sheaths at the top of 

 each culm branch and branchlet above the topmost node where branching ends. 

 This true leaf is persistent upon the sheath. The ligule is present, as in the fii'st 

 type, but the deciduous pseudophyll is replaced by an evergreen leaf. 



" An interesting question arises as to whetlier there is any transition stage 

 between the two types of blade, or whether the change is always sudden. I think 

 that in many Bamboos I can trace such a transition stage ; that is to say, that each 

 successive pseudophyll on the stem becomes more and more like a true leaf, something 

 of the nature of an arrested midrib being perceptible in the pseudophylls which are 

 found near the top of the culm, though it is not until the last branching node has 

 been passed that the true leaf -bearing sheaths occur. The principle remains in- 

 violate (throughout the hardy species at any rate), and the distinction between the 

 two classes of sheaths is absolutely maintained." — A. B. P. M. 



I would remark in conclnsion that Mr. Mitford's observations, extending to the 

 nervation of the leaves of Bamboos, lead him to the conclusion that of those cultivated 

 by him in the open air in the middle of England, the truly hardy only have tessellated 

 leaves ; the tender, such as Arundinaria JPalconeri and falcata^ having very incon- 

 spicuous transverse nerVules, or none. — J. D. H. 



Subtribe I. AauNDiNAHiEiE. (See p. 91.) 



132. ARUNDINARIA, MicAx. 



Erect or climbing shrubs. Stems slender, nodes usually prominent, 

 internodes rather short, branches short fascicled. Stem-sheaths papery, 

 straw-colrd., blade subulate. Leaves usually small, jointed on the sheatn. 

 Infl. on separate stems, or terminal, or on leafing branches. Spikelets 

 1- many-fld., compressed, usually all bisexual, except sometimes the 

 terminal, often sheathed; empty gls. 2, unequal, membranous; flg. gls. 

 longer, obtuse acute or muoronate, many-nerved ; palea 2-keeled. Lodicules 

 3, ciliate. Stamens 3, rarely up to 6. Ooary globose above ; style short, 

 stigmas 2-3 plumose. Grain ovoid or narrowly oblong, dorsally furrowed, 

 included in the gl. and palea. — Species about 50, 14 American, 1 African, 

 the rest Asiatic. 



