This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
The appearance alone, and the form of the flower, as well as can be produced in a picture, for want of an example from nature, oblige us to append to the Pharbitis this Ipomaea of authors. In adopting as a useful and probably natural division, this distinction of the Pharbitis from out of the still very irregular group of the Ipomaeas, it seems to us evidently impossible to separate the species in question from the Pharbitis hispida, Choisy (Convolvulus purpureus, L.), prototype of this group of Liseron's Annual, so popular for the decoration of windows, balconies, and green arbors.
Notwithstanding the tropical origin of the Pharbitis, it owes to its annual continuance as well as to its rapid development, the faculty, valuable to us, of vegetating aud flowering in the open air in our climate. It is, at least, true, of the common species, such as the Pharbitis' hispida and P. Nil; as to the less common species here figured from a cultivated specimen, last summer, in the van Houtte establishment, it appears to be of a more delicate nature.
Pre-eminently distinguished in the genus by its general smoothness, and by the remarkable shortness of the calyx divisions, this species probably varies in color, and does not always present the contrast of blue and violet carmine on the. two faces-of the corolla. Let us add that, in the pictures of the model plant, the angles are sharply acuminate, instead of being, as in the figure, slightly indented and obtuse. Should not this constitute a specific difference? A question impossible to determine without studying the plant itself.
The Pharbitis rubro-ccerulea comes from Mexico. It was introduced into England before 1834, by Mr. Samuel Richardson, then in the service of the Anglo-Mexican Society for the working of mines. We have every reason to believe that it is still very rare in the gardens on the continent. J. E. P.