40 DIDYNAMIA. ANGIOSFERMIA. 



Order II.— ANGIOSFERMIA. 



f Calix quinquifid. 



420. PHUTMA. i. 



Calix cylindric, upper lip longer, trifid; low- 

 er bidentate. Upper lip of the corolla emargi-- 

 iiate, lower much larger. Seed one. 



Spikes slender, terminal; flowers opposite, er\ch Iribrac- 

 teate; calix reflected downwards in fruit. (Perisperm 

 none; embryon flat; radicle superior! cotyledones ennar- 

 ginate.) 



Species. 1. P. leptostachya. The only known species. 



421. VERBENA. L. (Vervain.) 



Calix 5 cleft. Corolla funnelform, tube in- 

 curved, limb unequal, 5-lobed. Stamina 4, fer- 

 tile. Seeds 4. 



Generally herbaceous; flowers bracteate, alternate and 

 slenderly spiked, or rarely subcorymbose. 



Species. 1. V. .9ubletia. Abundant in Louisiana. 5. 

 spun'a. Apparently a mere variety of F. officinalis and ve- 

 ty common in the suburbs of Pliiladelphia and throttg-h- 

 out the s^ate of Delaware. 4. hnstata. Flowers deep 

 blue; leaves 'rarely if ever hastate. Of this species there 

 appears to be a very distinct variety near Philadelphia 

 which I shall distinguish by the name of /3.*o3/o%7/o/za, 

 having oblong-lanceolate deeply serrated leaves, merely 

 acute, and not acuminated; spikes filiform, paniculate; 

 flowers smaller, pale blue. May this be V. panieiduta 

 of Lamark? but the flowers are not imbricated, nor in 

 the least corymbose, it appears to be equally remote 

 from V. diffusa of the same, but assuredly intermediate, 

 if not an hybrid betwixt V. hastata and V. urticifolia. It 

 has only occurred to me twice on the banks of the Dela- 

 ware. 5. panicnJata. 6. iirticifolia. 7- diffusa. 8. ni^-o. 

 sa. 9. caroliniana. 10. stricta. Hirsute and canescent; 

 stem erect, leaves subsessde, oblong-ovate, obtuse and 

 serrate; spikes snbcylindric, rigid. Hab. Abundant 

 throughout the north western territories. 



An American genus of about 20 species indigenous to 

 both hemispheres, with the solitary exception of V- offci- 

 iialis. 



