HARD IVICKE ' S S CIE NCE - G SSI P. 



29 



mounted in glycerine jelly will show the spiral vessels 

 of which the bundles are composed. 



The leaves are in pairs, opposite. 



We now come to the third and very important 

 characteristic of the order, that is, the inflorescence. 

 This must be studied in Nepcta glechoma with great 

 care, because, though the flowers are small, they are 

 not so crowded as in many others ; such, for example, 

 as Lamium album, and therefore the peculiar inflor- 

 escence can be the better made out and understood. 



On a careful examination of the petiole at its 



So much for explanation ; but if you want a short, 

 clear definition of a verticillaster, here is one : — 



Verticillaster, a false whorl, formed of two nearly 

 sessile cymes placed in the axis of opposite leaves.* 



If you turn to Asa Gray on Structural Botany, you 

 will see that he, too, makes this matter very clear. 



This is fortunate, seeing that many find it difficult 

 to make out what a verticillaster really is. 



The bracteoles which are subulate equal in length 

 the short pedicels. 



We now come to the consideration of the flower. 



A\ 



Fig. 20. — Epidermis from lamina of leaf (unrlT 

 surface). A, cells; b, stoma; c, chlorophyll 

 bodies; D, oil reservoirs. 



Fig. 19. — Rough diagram showing 

 verticillaster inflorescence. 



Fig. 22. — Flower of X. glechoma, cut open and 

 folded back (much enlarged), a, Upper; c, di- 

 vided under lip ; is, lattral lobe u[ the corolla ; 

 i>, E, anthers conniving and forming a cross. 



Fig. 21. — Tetrago- 

 nal stem of A\ 

 zleclwma. 



Fg. 23. — Gynoecium of 

 N. glechoma. A, bifid 

 stigma ; h, style ; c, 

 ovary ; d, portion of 

 calyx. 



junction with the stem on each side, it will be seen 

 that the flowers borne on very short pedicels spring 

 from this axis (Fig. 19). In the case of Nepeta 

 glechoma, in from two to three on each side. The 

 general appearance of this manner of inflorescence is 

 misleading. It leads one to assume it is that of a 

 verticil. That is just what it is not. 



Seeing that the flowers proceed from the axis of 

 the petiole with the stem, the inflorescence is more 

 cymose than anything else. But the flowers are 

 nearly sessile, the pedicels being very short ; there- 

 fore we get a distinctive name for this peculiar in- 

 florescence, and we call it a Verticillaster. 



The calyx is tubular, persistent, and five-toothed ; 

 the teeth are recurved. 



The persistent calyx is a fourth characteristic of 

 the order ; the fruit being enclosed in the calyx, as 

 may be most commonly seen in such a plant as 

 Stachys sylvatica. The corolla is bilabiate, which is 

 a fifth and striking characteristic of the order. The 

 corolla tube is long ; the mid lobe of the lower lip 

 obcordate. The upper lip is bifid, the lower trifid ; 

 the mid lobe large. 



In looking down the corolla tube the picture is 



* Balfour's " Class Book of Botany," p. 1102. 



