FOOTNOTES:

Flowers and pods.

FOOTNOTES:[D]Todd Prof. J. E.: On the Flowers ofSolanum rostratumandCassia chamæcrista, Amer. Nat., vol. XVI, pp. 281-287, 1882. A brief review of Todd’s paper is given by Dr. P. Knuth, Handbuch der Blutenbiologie, Leipzig, 1898.[E]According to Carruth—Carruth, J. H., Catalogue of Plants seen in Kansas, with additions by Prof. F. H. Snow and Prof. E. Hall—S. rostratumfirst appeared in Kansas in 1864. This date probably refers to eastern Kansas. Dr. S. W. Williston informs the writers that it appeared around Manhattan in 1860 or 1861.[F]One specimen observed growing in rich soil back of a feed-store in St. Joseph, Mo., in early September had a diameter of over seven feet and a height of three feet. The plant might be considered as normally developed, having produced apparently the normal number of seed pods, and so would not be classed with the rank vegetative development which plants sometimes show when grown in very rich soil.[G]S. rostratumappears to be better adapted to xerophytic conditions by its extensive root system than by any adaptation for the prevention of evaporation of water. When cut down on a warm day, the plants wilt in a very few minutes. Roots extend down sometimes for more than three feet, so that the plants generally appear perfectly fresh when others around are wilted and drying up.[H]Mueller, Fritz: Two Kinds of Stamens with Different Functions in the same Flower, Nature, vol. XXVII, pp. 364, 365, 1883.[I]Experiments for the determination of the fertility of close and cross-fertilization are always interesting, but are of especial interest in the case of a plant such asS. rostratum, in which, if the method of pollination described by Professor Todd is the one actually depended upon, cross-pollination is sometimes possible and sometimes impossible on the same raceme. Of course, if, as suggested in the latter portion of this paper, the method of pollination suggested by Professor Todd is not the only one, these experiments do not have the interest which they otherwise would.[J]As will be remarked, the above insects were all taken August 5 and 6. Careful collecting extending over a considerable period of time would doubtless secure many other forms which visit the plant more or less frequently.[K]Meehan, Thomas: On the Fertilization ofCassia marilandica, Proc. Acad. Nat. Sci. Phila., 1886, pp. 314-318.[L]Meehan, Thomas,loc. cit.[M]It must be stated that in a later paper (Robertson, Charles: Flowers and Insects, V. Bot. Gaz., vol. XV, No. 8, pp. 199-204), Charles Robertson does not give the same results as those found by Thomas Meehan. Robertson says: “Two long stamens, one on each side of the style, furnish pollen for cross-fertilization. They have inflated anthers which probably have a bellows-like action, like the long stamen ofSolanun rostratumandRhexia virginica.” Meehan states expressly in his paper that in the case ofC. marilandicahe was sure no pollen was ejected, as Todd found forS. rostratum, since in the flowers, which were covered with a gauze bag, the membrane at the apex was never ruptured when the stamens were ready to fall. Robertson describes the method of extracting the pollen inC. chamæcristain a way which is essentially the same as Todd gives forS. rostratum. He then says, in speaking ofC. marilandica: “Four small stamens furnish pollen for the visitors. Bumblebees milk the pollen out of these, using their jaws, as in the case ofchamæcrista.” Meehan says: “Nor was there any draw-out of the pollen, as observed by Professor Todd. It is abstracted solely through the pores; and, although I could see no evidence that such was actually the case, I suspect that fertilization could only occur through some of this extracted pollen escaping from the insect to the stigma.” It must be noted here that the method which Meehan describes for the method of opening of the anthers, the pollen being “abstracted solely through the pores,” does not agree with the method described by other observers. Leclerc du Sablon, in a paper, “Recherches sur la Structure et la Dehiscence des Anthers,” in vol. I of the seventh series of Annales des Sciences Nouvelles, discusses the anatomical modifications of the anther walls, by which dehiscence is secured. His observations coverCassia cremophiliaandSolanum. His observations do not cover a sufficient number of species to make them of the greatest value in deciding the present points. The author presents, in a condensed form, his results in: Note sur la Dehiscence des Anthers, La Belgique Horticole, vol. XXXIV, pp. 148-150, 1884. Robertson says, in speaking of the central of the three long stamens: “Bees, no doubt, force the pollen out of this as they do from the short stamens.” Meehan says: “I watched a mass of plants containing eighty-eight flower-stems on the 30th of July, and the same lot for an hour on the 6th of August, but saw no attempt to get pollen from the longer anthers or to use them in any way but as a platform. It would indeed be hardly possible for the bee to stand anywhere so as to get power to pierce the apical membranes of the longer stamens. When the flower matured and the anthers were ready to fall they were examined-the four short ones were empty sacs-the three lower ones proved that they had not served any purpose to the bees, for they were full of pollen.”[N]This, of course, in case, as Meehan states, the large anthers do not dehisce. Of course the statement loses entirely its significance if, as Robertson states, the large stamens furnish pollen for cross-fertilization.[O]While the experiments made upon artificial pollination were very limited, it will be seen that the pollen from the large stamen in no case fertilized over twenty-nine per cent. of the flowers pollinated from it. These flowers, however, were on the same raceme; so the low per cent. might be due to this, or to the mechanical manipulation. The suggestion that the pollen of the large stamen is less fertile than that of the smaller ones is at least interesting as a working hypothesis.[P]Notes on Stamens of Solanaceæ, Bot. Gaz., vol. XV, pp. 103-106, 1890.[Q]Observations on the number of seeds produced and the surety of fertilization may be of especial interest, when the wonderful distribution which this plant has attained in recent years is taken into consideration. The original habitat ofS. rostratumwas the southwestern portion of the United States. It has since spread over a large part of the United States, in many places being recognized as a very noxious weed. It is also reported from several European localities. Reports on the destructiveness of the plant as a weed may be found in publications of the agricultural departments, as: Dewey, L. H., A Weed Bulletin, Farmers’ Series, No. 28, U. S. Dept. Agr.; Pammel, L. H., Two Noxious Weeds, Bull. Iowa Exp. Sta., 1895. L. H. Pammel,—Distribution of Some Weeds in the United States, especiallyIva xanthifolia,Lactuca scariola,Solanum carolineum, andSolanum rostratum, Proc. Iowa Acad. Sci., 1895, vol. II, pp. 103-127—gives the eastward migration of this weed up to 1895.[R]The racemes ofS. rostratumare produced by a scorpoid sympodial dichotomy of the branch, in which the racemes represent the alternate branches. At first the raceme develops much more rapidly than the bud which is to continue the main stem, and so the racemes, when flowering, are always well towards the outside of the plant.[S]Robertson, Charles,loc. cit.

[D]Todd Prof. J. E.: On the Flowers ofSolanum rostratumandCassia chamæcrista, Amer. Nat., vol. XVI, pp. 281-287, 1882. A brief review of Todd’s paper is given by Dr. P. Knuth, Handbuch der Blutenbiologie, Leipzig, 1898.

[E]According to Carruth—Carruth, J. H., Catalogue of Plants seen in Kansas, with additions by Prof. F. H. Snow and Prof. E. Hall—S. rostratumfirst appeared in Kansas in 1864. This date probably refers to eastern Kansas. Dr. S. W. Williston informs the writers that it appeared around Manhattan in 1860 or 1861.

[F]One specimen observed growing in rich soil back of a feed-store in St. Joseph, Mo., in early September had a diameter of over seven feet and a height of three feet. The plant might be considered as normally developed, having produced apparently the normal number of seed pods, and so would not be classed with the rank vegetative development which plants sometimes show when grown in very rich soil.

[G]S. rostratumappears to be better adapted to xerophytic conditions by its extensive root system than by any adaptation for the prevention of evaporation of water. When cut down on a warm day, the plants wilt in a very few minutes. Roots extend down sometimes for more than three feet, so that the plants generally appear perfectly fresh when others around are wilted and drying up.

[H]Mueller, Fritz: Two Kinds of Stamens with Different Functions in the same Flower, Nature, vol. XXVII, pp. 364, 365, 1883.

[I]Experiments for the determination of the fertility of close and cross-fertilization are always interesting, but are of especial interest in the case of a plant such asS. rostratum, in which, if the method of pollination described by Professor Todd is the one actually depended upon, cross-pollination is sometimes possible and sometimes impossible on the same raceme. Of course, if, as suggested in the latter portion of this paper, the method of pollination suggested by Professor Todd is not the only one, these experiments do not have the interest which they otherwise would.

[J]As will be remarked, the above insects were all taken August 5 and 6. Careful collecting extending over a considerable period of time would doubtless secure many other forms which visit the plant more or less frequently.

[K]Meehan, Thomas: On the Fertilization ofCassia marilandica, Proc. Acad. Nat. Sci. Phila., 1886, pp. 314-318.

[L]Meehan, Thomas,loc. cit.

[M]It must be stated that in a later paper (Robertson, Charles: Flowers and Insects, V. Bot. Gaz., vol. XV, No. 8, pp. 199-204), Charles Robertson does not give the same results as those found by Thomas Meehan. Robertson says: “Two long stamens, one on each side of the style, furnish pollen for cross-fertilization. They have inflated anthers which probably have a bellows-like action, like the long stamen ofSolanun rostratumandRhexia virginica.” Meehan states expressly in his paper that in the case ofC. marilandicahe was sure no pollen was ejected, as Todd found forS. rostratum, since in the flowers, which were covered with a gauze bag, the membrane at the apex was never ruptured when the stamens were ready to fall. Robertson describes the method of extracting the pollen inC. chamæcristain a way which is essentially the same as Todd gives forS. rostratum. He then says, in speaking ofC. marilandica: “Four small stamens furnish pollen for the visitors. Bumblebees milk the pollen out of these, using their jaws, as in the case ofchamæcrista.” Meehan says: “Nor was there any draw-out of the pollen, as observed by Professor Todd. It is abstracted solely through the pores; and, although I could see no evidence that such was actually the case, I suspect that fertilization could only occur through some of this extracted pollen escaping from the insect to the stigma.” It must be noted here that the method which Meehan describes for the method of opening of the anthers, the pollen being “abstracted solely through the pores,” does not agree with the method described by other observers. Leclerc du Sablon, in a paper, “Recherches sur la Structure et la Dehiscence des Anthers,” in vol. I of the seventh series of Annales des Sciences Nouvelles, discusses the anatomical modifications of the anther walls, by which dehiscence is secured. His observations coverCassia cremophiliaandSolanum. His observations do not cover a sufficient number of species to make them of the greatest value in deciding the present points. The author presents, in a condensed form, his results in: Note sur la Dehiscence des Anthers, La Belgique Horticole, vol. XXXIV, pp. 148-150, 1884. Robertson says, in speaking of the central of the three long stamens: “Bees, no doubt, force the pollen out of this as they do from the short stamens.” Meehan says: “I watched a mass of plants containing eighty-eight flower-stems on the 30th of July, and the same lot for an hour on the 6th of August, but saw no attempt to get pollen from the longer anthers or to use them in any way but as a platform. It would indeed be hardly possible for the bee to stand anywhere so as to get power to pierce the apical membranes of the longer stamens. When the flower matured and the anthers were ready to fall they were examined-the four short ones were empty sacs-the three lower ones proved that they had not served any purpose to the bees, for they were full of pollen.”

[N]This, of course, in case, as Meehan states, the large anthers do not dehisce. Of course the statement loses entirely its significance if, as Robertson states, the large stamens furnish pollen for cross-fertilization.

[O]While the experiments made upon artificial pollination were very limited, it will be seen that the pollen from the large stamen in no case fertilized over twenty-nine per cent. of the flowers pollinated from it. These flowers, however, were on the same raceme; so the low per cent. might be due to this, or to the mechanical manipulation. The suggestion that the pollen of the large stamen is less fertile than that of the smaller ones is at least interesting as a working hypothesis.

[P]Notes on Stamens of Solanaceæ, Bot. Gaz., vol. XV, pp. 103-106, 1890.

[Q]Observations on the number of seeds produced and the surety of fertilization may be of especial interest, when the wonderful distribution which this plant has attained in recent years is taken into consideration. The original habitat ofS. rostratumwas the southwestern portion of the United States. It has since spread over a large part of the United States, in many places being recognized as a very noxious weed. It is also reported from several European localities. Reports on the destructiveness of the plant as a weed may be found in publications of the agricultural departments, as: Dewey, L. H., A Weed Bulletin, Farmers’ Series, No. 28, U. S. Dept. Agr.; Pammel, L. H., Two Noxious Weeds, Bull. Iowa Exp. Sta., 1895. L. H. Pammel,—Distribution of Some Weeds in the United States, especiallyIva xanthifolia,Lactuca scariola,Solanum carolineum, andSolanum rostratum, Proc. Iowa Acad. Sci., 1895, vol. II, pp. 103-127—gives the eastward migration of this weed up to 1895.

[R]The racemes ofS. rostratumare produced by a scorpoid sympodial dichotomy of the branch, in which the racemes represent the alternate branches. At first the raceme develops much more rapidly than the bud which is to continue the main stem, and so the racemes, when flowering, are always well towards the outside of the plant.

[S]Robertson, Charles,loc. cit.

Transcriber's Notes:The cover image was created by the transcriber, and is in the public domain.Typographical errors have been silently corrected but other variations in spelling and punctuation remain unaltered.

Transcriber's Notes:

The cover image was created by the transcriber, and is in the public domain.

Typographical errors have been silently corrected but other variations in spelling and punctuation remain unaltered.

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