IG Mr. Woods on the Genera of Eurnpean Grasses. 



Here, again, we may employ the cotnpouncl terms IIerbaceo-membranous 

 and Herbaceo-scauiose to denote the intermediate states. The first occurs 

 in the glumes oï Phdhiris, and in the palcpe of Poa annua; the second, in the 

 glumes of .Intlioxantltani, and the glumes and paleœ of Trisetum. 



Coriaceous. Thicker and firmer than membranous, as in the paletc of 

 Plialaris. 



CoRiACEO-MEMBRANors would cxprcss an intermediate degree of consistency, 

 as in the paleœ of Mil'inni eff'asum. Ilerhaceo-coriaceous would denote a 

 difference of colour and texture rather than of substance ; we have it in tlie 

 paleœ of Sclerovltloa risi/da and Tr'ifkum loUaceuni. 



HoRNV. Harder than coriaceous. ']'he paleœ of Jndmpogon AUinnii may 

 well deserve this title, at least when the plant is in seeil, nor would it be mis- 

 applied to the paleœ of Panlciim, or the glume of Sorgliam saceharatum. 



Fleshy. This term may be applied to the additional scales which indicate 

 the exterior florets in some species of Phalaris, and to those of the interior 

 fîoret in Melka, but perhaps not correctly to either glume or palea. 



The shape of the glumes and paleœ, considered as flat surfaces, does not 

 appear to aflord us any good generic characters ; but their being navicular, 

 compressed, concave, nerved, furnished with a marked midrib, or ribbed, are 

 particulars to be attended to. In this respect also I find considerable differ- 

 ence in the use of words. We have canaUculatœ, ear/natœ, carinato-compressœ, 

 naviculares, navieular'i-carînatœ, concarw, concaro-eonipresscv, nav'iculurl-com- 

 pressœ, invo/itfa'. Concave and carinate seem by most authors to be placed in 

 opposition ; but Smith unites in the same description concave and keeled. In 

 considering the substance of a plant, I understand the compound terms, such, 

 for instance, as herbaceo-mend/ranaceoas, to indicate an intermediate state ; 

 but in the foregoing examples it would be hard to say what idea was intended 

 to be expressed l)y a form between buat-sliaped and heeled. Mertens and Koch 

 prefer considering the glume as convex instead of concave. 



The structure of the valve in this point of view consists of several particu- 

 lars unconnected with each other, whicli may or may not be combined, but 

 where in many cases we cannot with propriety speak of an intermediate form. 

 A navicular or boat-shaped glume is one so closed at the ends that it cannot 

 be opened into a flat surface. We find this in degree in the glumes of many 



