174 DISTINCTIVE CHARACTERS OF QUERCUS AND CASTANEA. 
remark that many true Oaks have more stamens than 10, though T 
cannot at this moment say whether they ever reach 15 (a point, in- 
deed, of no consequence, since they are so variable in number in these 
and allied genera, Fagus, etc.) ; and that the texture and superficies 
of the fruit-involucre, irrespective of its slight value, is by no means 
constant or reliable; so that in fact the cotyledons alone remain avail- 
able for sd discrimination. He has not alluded to the dehiscence in 
his chara 
Quite vend (1861), Professor Miquel, after an examination of 
most of the Corylacee hitherto detected in Dutch India, makes the 
following observation on the very close affinity of Quercus and Cas- 
lanea, and appends the subjoined clavis of these genera and their tiore 
— ate allies (Fl. Ind. Bat. Suppl. i. p. 353 
** Querciis, Castanee, et Calleocarpi genera, solis floribus haud tuto 
discernenda, vix fructuum etiam fabrica diversa satis dignoscuntur. 
Cupula enim in quibusdam Quercubus Indicis totam glandem includens, 
transitum struit ad ipsas Castaneas et Calleocarpi genus. — Profecto si 
florentia tantum specimina ad manus sunt, certum nullum exstare vi- 
detur trium generum discrimen, nam quod Quereu uni-, Castanee tři- 
florum olim tribui solebat involucrum fæmineum, nihil valere illae Indice 
Castanee probant, quee in eadem spica etching involucri speciem 
nobis exhibent. Attamen hee genera haud omnino arbitraria conser- 
vanda, hisce presertim characteribus discernuntur : 
** Cotyledones plano-convexee. Involucrum foem. 1-3-florum. Cupula 
nunc in involucrum indehiscens aucta, 1-nucularis. 
* Pericarpium coriaceum, leve : Quercus. 
** Pericarpium lapideum, rugosum : Lithocarpus. 
Cotyledones intus plicatee, cohzerentes, involucrum quadrivalve, nueulis 
iquetris 2-3: Fagus. 
Cotyledones tortuose. Involucrum 3-1-florum. 
T Froctiis involucrum coriaceum, spinis longis echinatum, 3—1-nueu- 
lare quadrivalve : Castanea. 
Tt Fructüs involuerum lignosum, crassum, processubus prismaticis 
undique extuberantibus, 3-1-nuculare, indehiscens, demum 
irregulariter ruptum: Calleocarpus.” | 
From this it will be observed that the sole tangible difference between 
Quercus and Castanea lies in the structure of the cotyledons, and the 
subordinate mark of the echinate involucre of the latter. The state- 
