NOMENCLATURE OF THE STEM. 49 



either fleshy, as in the common house-leek and most sea-weeds; 

 spongy, as in the Indian corn, great cat's-tail, and the mushroom 

 tribe ; or hollow, as in the common dropwort, castor-oil plant, and 

 almost all the grasses. 



7. Form: In difference of form, stems are either 

 round, semicircular, compressed, angled, angulosed, 

 knotted, jointed, or kneed. 



a. Hound when they have no angles, as in the thorn-apple and 

 changeable hydrangea. 



b. Semicircular half round ; that is, round on one side and flat 

 on the other. 



c. Compressed when they are flat, as in the spleen-wort and 

 flat-stalked meadow-grass. 



d. Angled when they have several acute angles in their circum- 

 ference. Angular stems may be obtuse ; three, four, live, six, or 

 many-cornered ; acute and triangular ; four, five, six, or many-angled ; 

 or three-sided, when there are three flat sides forming acute angles. 



e. Angulosed when the angles are either very obscure, and the 

 stem consequently, can scarcely be placed in either of the foregoing 

 arrangements ; or that the angles are variable in number, and 

 which may be farrowed, as in common Alexanders, or striated, as in 

 the common sorrel. 



f. Knotted when stems are divided at intervals by swellings 

 or knots, as in the knotty crane's-bill. 



g. Jointed when they are composed of joints, or apparently dis- 

 tinct pieces, united at their ends. 



h. Kneed when a jointed stem is more or less bent at each joint, 

 as in the floating fox-tail-grass and three-flowered fescue-grass. 



8. Mode of branching : From the mode of branching, 

 stems are dichotomous, trichotomous, slightly-branched, 

 much-branched, or abruptly-branched. 



a. Dichotomous or forked when the divisions and subdivisions, 

 are, throughout, in bifurcations ; as in the corn-salad, petty spurge, 

 and forked marvel of Peru. 



b. Trichotomous when, instead of being bifurcated, the divisions 

 are trifld,as in the common marvel of Peru. 



v 



