212 Froceedings of tJw Royal Irish Academy. 



c. Hypoderma at margins of leaf, 

 and at each, side of the resin 

 canal ; margins of leaf slightly 

 reilexed ; serrulate ; apes ob- 

 tuse, 5. T, BEimoNiAirA. 



II. Young shoots glabrous; hypoderma at 

 margins of leaf only ; margin of leaf 

 entire ; apex emarginate, sometimes ob- 

 tuse ; stomata on under surface of leaf 

 only. . • . . . . , 6. T. SiEBOLDn. 



1. Pinus (Tsuga) Hookeriana. 



Abies Hookeriana A. Murray, Edinburgh ISTew PhilosopTi. 

 Journal, 1855, p. 289. 



Tsuga Hookeriana Carr. ? not of Bertrand. 



Shoots haiiy ; leares four to seven lines in length, irregularly 

 bifarious ; margin entire ; apex obtuse ; t"^o sides of leaf similar dark 

 green, with four to six rows of stomata on each side of the middle 

 line. Plate 23, fig. 1. 



2. Pinus (Tsuga) Pattoniana. 



Abies Pattoniana Jeffr. Oregon Bot. Exped. 3. 



Shoots hairy; leaves six to nine lines long, iiTegularly bifarious; mar- 

 gin denticulate near the obtuse apex ; upper side yellowish green, with 

 from two to four rows of stomata on each side of the slightly marked 

 central fnrrow, beneath with six to seven rows of stomata on each side 

 of the middle line. Plate 23, fig. 2. 



The forms cultivated in the Edinburgh. Botanic Garden, under the 

 names of Abies Parryana and Abies Hanburyana, carin.ot be separated 

 by any characters from P. Pattoniana. This is not Pinus Pattoniana 

 of Parlatore, as lie includes both this species and P. Hookeriana. 



3. Pinus (Tsuga) canadensis Linn. Parlatore. 



Shoots hairy ; leaves six to nine lines long in two rows ; margins 

 rough ; apex obtuse ; upper side dark green, with a central fun-ow, 

 beneath with eight or nine rows of stomata on each side of the promi- 

 nent resin canal. Plate 23, fig, 3. 



4. Pinus (Tsuga) Mertensiana Bougard. Parlatore. 



Shoots hairy ; leaves four to seven lines long in two rows ; margins 

 ciliate ; apex obtuse ; upper side dark green, with a central furrow, 

 beneath with eight or nine rows of stomata on each side of the middle 

 line, where the hypodenn is developed. Plate 23, fig. 4. 



The forms cultivated in the Edinburgh Botanic Gardens, under 

 the names of Abies Albertiana, Abies Bridgesii, and Abies "Williamsonii, 

 cannot be separated by any characters fi'om P. Mertensiana, 



