19--] Sctchell-Goodspeed-Clausen: Nicotiana Tahacum 495 



In stature, as previously mentioned, calycina belongs to the low 

 corymbose group of Tahacum forms. In height the central axis usually 

 varies between 60 and 75 cm. The laterals, however, which develop 

 later from the base, overtop the central axis and reach a height of 

 120 to 135 cm. Like macrophylla, central axis and laterals bear close 

 panicles of corymbose racemes, the laterals developing successively 

 from the base. The stems and branches are stouter than those of 

 angustifolia and the leaves do not droop so considerably. In these 

 respects calycina occupies an intermediate position between angusti- 

 folia and macrophylla. 



The leaves of calycina, as plate 79 will show, are sessile, but they 

 are distinctly different from those of either angustifolia or macro- 

 phylla. Curiously enough, however, they do rather closely approxi- 

 mate certain of the derivatives of the an g ustifolia-macrophylla series, 

 as, for example, the lanceolata and loriifolia leaves of types 13 and 

 14 respectively, illustrated in plates 75 and 76. The leaves vary from 

 broadly to narrowly lanceolate, tapering toward both base and apex, 

 and usually with a long curved tip. The broader leaves are borne at 

 the base of the plant, those above them becoming successively narrower 

 in a continuous series until the linear leaves or straplike bracts of the 

 inflorescence are reached. There are no auricles at the base of the leaf. 



The inflorescence is in the form of a very close panicle of racemes, 

 the secondary axes of which are mostly patent, and more or less re- 

 curved or bent back. The flower as a whole is of a very characteristic 

 split hose-in-hose type. The corolla is usually split on one side, some- 

 times twice split, and more or less curved. The characteristic split- 

 ting of the corolla is seen even in very young buds and often the pistil 

 protrudes from them. Typically the calyx has an elongated whitish 

 green tube, with 3 to 5 of its tips more or less petaloid. Sometimes 

 strips of petaloid tissue extend down the entire length of the calyx. 

 The pod is ovoid oblong in shape. As it enlarges it splits the calyx, 

 which then withers and drops off like the corolla, leaving a naked, 

 whitish green capsule. The flower color is red fading to bluish purple, 

 apparently the same as that of macrophylla. 



Virginica is represented by U. C. B. G. 78/05, a strain received 

 from the United States Department of Agriculture under the identi- 

 fication number "205-20-7." It is figured by Setchell, plate 3, and 

 by Goodspeed and Clausen, plate 41, figure 1. The typical leaf and 

 flower characters are well represented in plate 80 herewith. 



In stature virginica. belongs to the moderate pyramidal group of 

 Tahacum varioti(>s. It is coiispicnously taller tlian calycina, the ceii- 



