SOLANUM 
573 
or capsule. Embryo curved or straight, in endosperm. The firs, are 
conspicuous and insect-visited ; some, e.g. Nicotiana, are adapted to 
Lepidoptera. A few are economically important, e.g. Solanum 
(potato), Nicotiana (tobacco), Lycopersicum, Capsicum, &c. ; Datura, 
Atropa, &c. are medicinal ; several are favourites in horticulture. 
Classification and chief genera (after von Wettstein) : the S. are 
nearly related to Scrophulariaceae, the most general distinction being 
the oblique ovary ; this however is by no means easily made out, and 
the zygomorphism of the fir. is most often used as a distinction. 
Certain genera of S. are nearly related to various Boraginaceac, 
Gesneriaceae, Nolanaceae, &c., and it is quite possible that the S. are 
not really a simple family (see Nat. Pfl.); they occupy a middle place 
between the Tubuliflorae with actinomorphic, and those with zygo- 
morphic firs. 
A. Embryo clearly curved, through more than a semicircle. All 
5 sta. fertile, equal or only slightly different in length. 
I. NICANDREAE (ovary 3 — 5-loc., the walls of the loc. 
dividing the placentae irregularly) : Nicandra (only genus). 
II. SOLANEAE (ovary 2-loc.): Lycium, Atropa, Hyoscya- 
mus, Physalis, Capsicum, Solanum, Lycopersicum, Mandra- 
gora. 
III. DA TUREAE (ovary 4-loc., the walls dividing the pla- 
centae equally) : Datura, Solandra (only genera). 
B. Embryo straight or slightly curved (less than a semicircle). 
IV. CESTREAE (all 5 sta. fertile); Cestrum, Nicotiana, 
Petunia. 
V. SALPIGLOSSIDEAE (2 or 4 sta. fertile, of different 
lengths) : Salpiglossis, Schizanthus. 
[Placed in Polemoniales by Benth. -Hooker, who unite Nolanaceae to 
S. ; in Personatae by Warming.] 
Solanum (Tourn.) Linn. (excl. Lycopersicum Hill). Solanaceae (11). 
900 sp. trop. and temp. S. Dulcaniara L. (bittersweet, nightshade) 
and S, nigrum L. in Brit. The firs, are small, with a cone of 
anthers opening at the tip as in Borago. S. tuberosum L. (S. Am.) is 
the potato. F rom the axils of the lowest leaves there spring branches 
which grow horizontally underground and swell up at the ends into 
tubers (potatoes). That these are stem structures and not roots is 
shown by their origin and by their possession of buds — the ‘ eyes.’ 
Each eye is a small bud in the axil of an aborted leaf (represented by 
a semicircular rim). When the parent plant dies down in autumn 
the tubers become detached, and in the next season they form new 
plants by the development of the eyes, at the expense of the starch 
and other reserves stored in the tuber (see p. 152). By heaping earth 
against the stem, so as to cover more of the leaf-axils, more of the 
axillary shoots are made to become tuber-bearing ; hence the value of 
ridging potatoes. S. Melongena L., the egg-fruit, is cultivated in the 
