1897.] NATURAL SCIENCES OF PHILADELPHIA. 173 



casionally occurs on a plant which generally has the pedicels more 

 or less curved. Some Gloxinias and other Gesneriaceous plants will 

 readily recur to the intelligent observer. Gesneria elongata, a South 

 American species, popular in garden culture, often has these erect 

 flowers. In this case the flowers are perfectly regular, and of a 

 different character in other respects from the normal ones. 



During the past season I was able to add a new illustration to 

 the list in Pentstemon barbatus. In a large bed with several hun- 

 dred flower stems, I collected some twenty erect flowers. In the 

 normal condition, the three lower segments constitute a lip, and 

 are so tightly recurved that they press against the tube ; the upper 

 two are erect, and form an upper lip. But in the exceptional flow- 

 ers noted, this is all changed. The lobes of the corolla are equal, 

 recurved, and pressed against the tube. But the most remarkable 

 change occurs in the fifth or barren stamen. In the normal form 

 this is so differently constructed from the other four that thoughtful 

 observation has to be given before deciding that it is a stamen at 

 all. In these erect, regular flowers there is not the slightest differ- 

 ence between any of the stamens. The fifth is the exact counter- 

 part of the other four. Each one of the five stamens are alternate 

 with the five regular lobes, as they should be in any well-ordered 

 regular flower. Assuredly if a plant always had flowers like these, 

 and only these flowers, it would not be a Pentstemon, but be made 

 to constitute a wholly different genus, if it were not, indeed, referred 

 to another natural order, for a two-lipped and more or less irregular 

 corolla is regarded as a leading characteristic in Scrophulariacese. 



We may say that nothing but a different degree of growth-energy, 

 accelerating or retarding the spiral development, so that that which 

 should have been left curved was advanced to (or left in) a straight 

 condition, had anything to do with the remarkable change. 



And then we may ask if such remarkably distinct forms can be 

 produced on the same plant, and in an exceptional way, what is to 

 prevent the plant from regularly exercising the same force, and thus 

 making the irregular flower the exception ? That this can be done 

 is.shown in the case of the upright and nodding lilies already cited, 

 though we have no evidence that a regular and irregular lily ever 

 grew on the same plant, as here produced by a Pentstemon. Ex- 

 amples might be found if carefully looked for. 



That these vagaries, once brought into existence, have hereditary 

 powers, is too well known to horticulturists to need more than a 



