464 University of California PuhUcations in Botany [Vol.5 



lateral, in turn, developing a corymbose cluster of racemes, rising 

 more or less above its predecessors. The result is tbat the whole plant 

 has the short corymbose habit mentioned above. The stems and 

 branches of angiistifolia are comparatively slender, being much more 

 slender than those of macrophylla, or those of any other of the Tdbacum 

 varieties except those of calycina, which are very similar. 



The leaves of angustifolia are alternate and distinctly and moder- 

 ately long petiolate. The blade of the lower leaves is ovate-lanceolate, 

 tapering above to a long, curved point, more or less conduplicate below 

 and with the rounded bases unequal. Above, the leaves are less con- 

 duplicate, more so even at the base, with the petiole shorter, while the 

 uppermost (bracts) become almost sessile and narrowly lanceolate even 

 to almost linear in outline. The normal petiole is naked at the base 

 and in the middle portion, but the base of the blade is slightly and 

 narrowly decurrent along the upper portion. Occasionally a petiole 

 shows a narrow wing throughout its length and at times the petioles 

 of all the leaves on certain plants are more or less winged, but the 

 majority of the plants have naked petioles (cf. also Goodspeed and 

 Clausen, 1917, p. 306, pi. 46, right-hand figure). The leaves of angus- 

 tifolia have also a very characteristic drooping habit, much more pro- 

 nounced than in any other Tabacum variety except calycina. In older 

 plants, after capsule formation has well advanced, all the leaves are 

 hanging obliquely downwards. 



The flower of angustifolia is distinctive and differs in details of 

 shape and color from that of any other Tahacum variety, and especially 

 from that of macrophylla. The general shape of the flower is that of 

 all the Tahacum section, but the corolla is much more slender and more 

 gradually infundibuliform than that of any of the other varieties re- 

 ported here. The calyx is broadly campanulate, prolonged above into 

 5 long, but unequal, linear-lanceolate, pointed lobes, of which one is 

 longer than the remaining four and gives the calyx a zygomorphic 

 appearance. The corolla is narrow and tubular below the middle, 

 expanding rather gradually and evenly above into a conical infundi- 

 bulum which bears the spreading, deeply 5-lobed limb at its summit. 

 The length of the tube of the corolla is about 6 cm. and its greatest 

 diameter about 7 mm. The limb of the corolla, at first erect (opening 

 bud), then horizontal, finally becomes somewhat deflexed and measures 

 about 3 or 3.5 cm. across. It is divided almost to the tube into 5 lobes 

 which are ovate-lanceolate with long, narrow, tapering tips. The lobes 

 of angustifolia are much longer and have narrower tapering tips than 



