374 Minnesota Plant Life. 



heads, and not in one-sided racemes. The fogh'uits liave two- 

 lipped flowers, and it is doubtful whether any of them actually 

 occur in Minnesota. The fruits of the verbenas, when mature, 

 separate into four nutlets, just as do the fruits of the borages. 

 If there is any (juestion whether a plant is a verbena or a borage 

 it may generally be decided by opening the corolla tube and 

 counting the stamens adherent to its inner surface. If there 

 are four, the plant is a verbena: if there are five, it is a borage. 

 Of course there are a great many other kinds of plants with 

 four stamens, but the combination of four stamens on the corolla 

 tube, flowers in racemes, spikes or heads, and fruits consisting 

 of four nutlets, pretty distinctly indicates a verbena. 



The six verbenas of Minnesota may be distinguished as 

 follows : One of them is a mat i)lant, growing in waste 

 fields along roadsides and on prairies. The whole i)lant-body 

 is prostrate and often spreads out over a circle a yard in 

 diameter. The flowers are purplish-blue and borne in spikes. 

 The leaves are of various shapes, but some of them, at least, 

 are likely to be cut, from the margin toward the midrib, by 

 deep notches. The hoary verbena is recognized by the soft, 

 hairy leaves, of an ovate form, almost stemless, with the edges 

 sharply notched. The blue flowers stand in dense leafy spikes. 

 No other verbena has this soft hairy leaf-surface. The nettle- 

 leafed verbena and the wild blue verbena also have ovate or 

 oblong leaves, but in these varieties each leaf has a distinct stem. 

 The nettle-leafed verbena has usually wliite flowers or i)ale 

 blue, while the blue \erl)ena, as its name indicitcs, ])roduces 

 bright blue flowers. The other two verbenas have difl'erent 

 foliage from the erect forms that ha\e been mentioned. The 

 narrow-leafed \erbena has very slender, or at most, willow- 

 shaped leaves with blue flowers in slender, dense spikes. The 

 Kuropean \-erbena, with an erect habit, has. at least on the lower 

 ])art of its stem, leax'es (leei)ly toothed to the midrib, like those 

 of the ])rostrate verbena. The flowers arc i)ur])le or white, 

 produced in numerous. \ery slender spikes, three to six inches 

 in length. 



