Iam led to write this paper partly for the reason that the problem

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1 THE NEW PHYTOIiOGIST. VOL. XII, No. 7. JULY, [PUBLISHED JULY 26TH, 1913.] THE PROBLEM OP THE ORIGIN OF CENOTHERA LAMARCKIANA DE VRIES. BY BRADLEY MOORE DAVIS, University of Pennsylvania. [WITH ONE FIGURE IN THE TEXT]. Iam led to write this paper partly for the reason that the problem of the origin of (Enothera Lamnrckiana De Vries has in the past few months became far more tangible than formerly, but chiefly because it seems probable that certain phases of the problem can be solved only by studies on the development of certain English CEnothera floras. I have then the hope that a brief outline of the situation, as it now appears to me, will be of some assistance to British botanists interested in the subject. Recent studies' clearly indicate that the Lfl;Karc^/a?m of the cultures of De Vries cannot be identified with the plant described by Lamarck' under the name Mnothera grandiflora from material grown in Paris at about 1796 or earlier and renamed by Seringe' (Enothera Laniarckiana, The evidence is very strong that Lamarck's plant {(Enothera Lamarckiana Seringe), was a form of (Enothera grandiflora Solander* (0. gratidiflora "Aiton") introduced into England in 1778 from Alabama. This disposition of (Enothera Lamarckiana Seringe as a form of 0. grandiflora Solander relieves our problem from association with the early date of 1796 and allows us to pass to later periods when we may hope for more direct evidence than that furnished by old descriptions and figures. The attempts to establish the presence» Davis B. M. " Was Lamarck's evening primrose ((jewott^ra LflwaKfftmHfl Seringe) a form of (Enothera grandiflora Solander? " Bull. Torrey Bot. Club, vol. 39, p. 519, Lamarck. Encyclopedic Methodique Botanique, vol. 4, p. 554,? 1798.» Seringe, N. C. De CandoUe, Prodromus, vol. 3, p. 47, Solander, D. Aiton, Hortus Kewensis, vol. 2, p. 2, 1789.

2 234 Bradley Moore Davis. of O. Lamarckiana De Vries in Europe at dates previous to 1796 are, to the writer, not convincing and have been discussed in previous papers.' In a recent contribution Gates" abandons his former views and admits (pp ) that the presence of Laniarckiana in Europe previous to 1760 is not established. Since CEnothera Lamarckiana Seringe becomes a synonym of O. grandiflora Solander, I have proposed that the plant of De Vries retain the name under which it is known in the extensive literature of experimental morphology, but the name must be written CEnothera Lamarckiana De Vries. In making the above suggestion it should be noted that 0. Lamarckiana De Vries has come down to us as the product of the f>arden through a long history of cultivation and that there are good reasons for believing it to be of hybrid origin. We have no evidence that the plant is present as a native species of any flora. As a garden plant we are apparently justified in giving it the name CEnothera Lamarckiana De Vries by Article 50 of the nomenclatorial code formulated by the International Botanical Congress held in Vienna in There is little doubt that the material of De Vries's cultures was derived, possibly greatly modified, from certain plants placed upon the market by the seedsmen Carter and Company of London at about These plants were considered by Lindley to be CEnothera Lamarckiana Seringe, but we cannot accept this identification as correct. However, this opinion of Lindley gave the name Lamarckiana under which seedsmen are to this day selling a somewhat heterogeneous mixture of forms. The description of the cultures of Carter and Company,' accompanied by an obviously inaccurate figure, gives us very little information on the plants. We are told that they were 3-4 feet high, very hardy biennials, and with flowers 4 inches in diameter. Carter and Company state that their plants came from seed received unnamed from Texas. The problem of the oi-igin of CEnothera Lamarckiana De Vries at present largely centers on the probable composition of the cultures of Carter and Company, and every effort should be made to bring forward evidence on the characters of these plants. The only information so far at hand apart from the unsatisfactory description ' See Davis, American Naturalist, vol. 45, pp , 1911, and vol. 46, pp , = Gates, R. R. "A Contribution to a Knowledge of the Mutating CEnotheras." Trans. Linnean Society, Botany, vol. 8, Part I, The Floral Magazine, vol. 2, plate 78, 1862, :

3 Origin 0/Qinothera Lamarckiana De Vries, 235 and plate in " The Floral Magazine " is that furnished by a very important sheet in the Gray Herbarium of Harvard University. This sheet I shall again describe and figure in the hope that it may lead botanists to maue a persistent search for herbarium material that may throw further light on the problem. Fig. 1. Sheet hi the Gray Herlparium of Harvard University. kncenotheya grown by Dr. Asa Gray at Cambridge, Massachusetts, in 1862 and probably derived directly or indirectly from the cultures of Carter and Company, of London, which were distributed under the name Lamarcliiana. This plant differed from CEnolheya Lamayckiana De Vries in the longer internodes of the inflorescence, in the larger and more leaf-lilce bracts, in the more slender form of the buds, in the more attenuated sepal tips, and in the longer seed-capsules. The sheet in the Gray Herbarium (Fig. 1) holds specimens of a plant " Oe.Lamarekiana" grown in Cambridge, Massachusetts, in 1862 by Dr. Asa Gray. From records upon the sheet ^ it appears quite certain that Dr. Gray received seeds from William Thompson ' See Davis, American Naturalist, vol. 46, p. 417, 1912.

4 236 Bradley Moore Davis. of Ipswich, England, a seedsman who probably obtained from Carter and Company their novelty. It is then possible that the plant grown by Dr. Gray was not more than one or two generations removed from the original cultures of Carter and Company. The following is a description of the sheet in the Gray Herbarium illustrated by Fig. 1 : 1. Stems and Foliage. The stem bears long hairs arising from papillie which are colored red as in Lamarckiana and are about as numerous as in that species. The large detached leaf, about 18-5 cm. long with sinuate margins, slightly lobed below, and with some evidence of former crinkles, suggests by its shape (although too small) the basal leaves oi Lamarckiana. The leaves of the upper foliage, short petioled, are not so nearly sessile as those of Latnarckiana. 2. Inflorescence. The inflorescence has longer internodes than in Lamarckiana and consequently is not so compact. The bracts are broad at the base, slightly toothed, and persistent, becoming large, lanceolate leaves on the fruiting branches: those oflamackiana remain much smaller. 3. Buds. The buds are about 9-5 cm. long, not stout and 4-angled as in Lamarckiana. The sepal tips are more attenuate than in Lamarckiana, projecting 1 cm. beyond the folded petals. The pubescence upon the sepals consists of long hairs arising from papillse among much shorter hairs as in Lamarckiana. 4. Flowers. The petals are about 4-5 cm. long, as long as those of the largest forms of Lamarckiana. The stigma lobes are about 8 mm. long, and close to 5 mm. above the tips of the anthers, in these respects agreeing with large-flowered forms oi Lamarckiana. 5. Capsules. The capsules, about 3 cm. long, are longer than those of Lamarckiana and not so stout. From the above it will be noted that the plant grown by Dr. Gray differed from the Lamarckiana of the cultures of De Vries in the longer internodes of the inflorescence, in the larger more leaf-like bracts, in the more slender form of the buds, in the more attenuated sepal tips, and in the longer seed capsules. It would profit little to discuss at present whether or not this plant was truly representative of the cultures of Carter and Company and whether or not their plants became greatly modified during the quarter century before the time when De Vries began his studies, at about 1886, and isolated the form that we know to-day as CEnothera Lamarckiana De Vries.

5 Origin of CEnothera Lamarckiana De Vries. 237 What we desire is further information on the composition of the cultures of Carter and Company through the discovery of other herbarium material of about the same date (1862) as that of the sheet in the Gray Herbarium. It will be strange if Dr. Gray proves to the only botanist who preserved specimens of the " Lamarckiana " placed on the market by Carter and Company. There should be made a persistent search through herbaria to bring forward any specimen that may throw light upon the problem. This is a matter in which it would seem that the British botanists can render a great service. Another feature of the problem concerns the development of some remarkable (Enotheraflorasin parts of England composed in greater part of 0. Lamarckiana or variants from this type. It is surprising how common have become Lamarckiana-like forms in England. During the past three years several English botanists have kindly replied to my request for seed of broad-leaved forms of CEnothera bienuis with green stems bearing red papilla; at the base of long hairs. From the seed sent to me I have grown eleven different cultures in the hope of finding a type of biennis which in the past I have greatly desired as a parent for a cross with 0. graiidiflom. All of these cultures have proved to be forms essentially Lamarckiana as to habit, foliage and stem coloration, but with smaller flowers than is usual for De Vries's plant. They correspond very closely and some ot them are indistinguishable from the small-flowered races of Lamarckiana which I have differentiated from material of De Vries.' They were not at all the forms of biennis that I hoped to obtain, and could not be used in my experimental work. The type of biennis that I wish should agree closely in morphology with the biennis of the sand dunes of Holland, but it should have the stem coloration characteristic of Lamarckiana, i.e., the green portions of the stems should be punctate with red papillje at the base of the long hairs. Tbe Dutch biennis has as far as we know a clear green stem above, but it would not be surprising if a form should be found with the stem coloration of Lamarckiana, since races of American biennis occur differing only in the presence or absence of red coloration in the stem papillse. Seeds of a type agreeing with the Dutch biennis have been sent to me from the botanical garden of Cambridge University and presumably the plant ' See Davis, American Naturalist, vol. 46, p. 383, 1912.

6 Bradley Moore Davis. is not uncominoii in England. De Vries ' reports (p. 32) that it is present on the sand hills of Lancashire. This plant which I have referred to as the Dutch hiennis, so well known through the studies of De Vries, is perhaps the most important type in the hieniiis assemblage of races and should he familiar to all students of oenotheras. It is very old having apparently been on the sand dunes of Holland since pre-linnean times. Bartlett^ has recently brought forward strong reasons for regarding the plant as the form known to Linnseus as (Enothera biennis and consequently to he regarded as the type-form of the species. It is very important that British botanists should endeavour to trace the history of this species in England and its relations to the present (Enothera floras. I shall be glad to supply seeds of the plant to anyone interested in the study. To return to the specific problems of the origin and development of Lamarckianaflorasin England the most important and historically the most interesting flora seems to be that of the Lancashire sand hills north of Liverpool. From the studies of several botanists it appears that over an extensive area 0. Lamarckiana De Vries occurs mixed with variants from the type proper. It is reported by Gates (I.e. 1913) that 0. grandiflora is also present with the Lamarckiana and we have De Vries's statement (I.e. 1912) that the Dutch biennis (0. biennis Linnseus) is in the same region. The studies of Gates (I.e. 1913) clearly show that among the types there is a large amount of hybridization and consequently a very complex mixture of forms differing among themselves in many respects. We know that a conspicuous (Enothera flora was present on the sand hills of Lancashire before 1806,^ and the problem is briefly the determination of its original character and the tracing of its modification or development down to present times. The account by Smith in the "English Botany" (1806) together with the accompanying figure of James Sowerby's indicate a biennial plant, 2-3 feet high, a stem "rough with minute tubercles," leaves broad and the lower decidedly crinkled, flowers with petals about 3 cm. long (if drawn natural size), and stigma lobes slightly above the tips of the anthers. There is no mention of red coloration in the stem tubercles which suggests a plant with green stems as in the Dutch ' De Vries H. " Die Mutationen in der Erblichkeitslehre.'' Berlin, Bartlett, H. H. "The Delimitation of (Enothera bieimis L." Rhodora vol. 15, p. 48, English Botany, vol. 22, p. 1543, 1806.

7 Origin of CEnotheta Lamarckiana De Vries. 239 biennis and if the petals were really no more than 3 cm. long the flower size was also closer to this species than to the large-flowered forms of Lamarckiana. On the other hand the stigma lobes figured somewhat above the tips of the anthers are in a position more like that in Lamarckiana than in tlie Dutch biennis where the stigma lobes lie below the tips of the anthers and pollination takes place before the opening of the bud. In the third edition of the "English Botany" Syme' gives a description of " (Enothera biennis Linn." and states it to be "now perfectly established on the Lancashire coast, at Crosbie, near Liverpool, and occuring occasionally throughout Britain, but generally an outcast from gardens." The description of this plant is accompanied by a somewhat different figure from that in the edition of 1806, but the twofiguresagree in all essentials of structure. The figure and description indicate a plant 2-3 feet high, rosette leaves oblanceolate-elliptical 6 inches to 1 foot long, stem leaves elliptical 3-6 inches long, all leaves short petioled and with thick white midribs, repand denticulate; flowers with petals lj to 1^ inch or more across (about 3-4 cm.), stigma lobes figured somewhat above the tips of the anthers; "plants dull green, sub-glabrous, with the stem, calyces, petioles, midribs, and margins of the leaves more or less hairy." In this account, also, as in that of the first edition (1806) there is no mention of that stem coloration characteristic of Lamarckiana, i.e., red papillae on green portions of the stem. This point together with the statement that the plant is dull green suggests the Dutch biennis but the large petals and the position of the stigma indicate a plant with flowers more like those of Lamarckiana, It ought at least to be possible to determine through herbaria whether or not the " (Enothera biennis " described in the different editions of the " English Botany " is the same fofm or one similar to the Dutch biennis which probably represents the (Enothera biennis of Linnaeus. It ought to be possible to obtain evidence through herbaria for or against the possibility of the presence in England of O. Lamarckiana De Vries at a date as early as 1806 or at least previous to There should be some direct evidence whether or not O. Lamarckiana was first introduced into England through the cultures of Carter and Company at about 1860 and whether or not its appearance on the sand hills of Lancashire is of an earlier or a later date. English Botany, Third Edition, vol. 4, p. 24, 1865.

8 24D Bradley Moore Davis. I have certain vievi^s on the subject but my purpose is not to present them at this time but to plead that a strong effort be made to fix the approximate date of the appearance in British CEnotheraflorasof the biennis of Linnaeus (probably represented by the Dutch plant) and of 0. Lamarekiaiia De Vries. The characters that are likely to be most helpful in distinguishing these species on herbarium sheets are: 1. The presence in Lamarckiana and absence in the Dutch biennis (so far as is known) of red in the stem papillae. It must be borne in mind, however, that some races close to the biennis of Linnaeus have the stem coloration of Lamarckiana. 2. The size of the petals, cm. long in the large-flowered forms of Laiiiarekiana and cm. long in the Dutch biennis. There are small-flovvered races of Lamarckiana the petals of which are of about the same size as those in the Dutch biennis. 3. The position of the stigma 5-7 mm. above the tips of the anthers in the large-flowered Lamarckiana (open pollinated) and well below in the Dutch biennis (close pollinated in the bud). The small-flowered races oi Lamarckiana sometimes present the stigma in a lower position more like that of the Dutch biennis. 4. The coloration of the sepals, sometimes streaked with red in Lamarckiana but normally green in the Dutch biennis. De Vries has suggested that what I have termed the smallflowered forms of Lamarckiana may be hybrids between the largeflowered type and biennis, but it is also possible that they are variants from Lamarckiana, itself a hybriil. It seems most unlikely that Great Britain has no herbarium sheets that can throw lijjht on these problems. Most interesting from my standpoint is the problem of the first appearance in England of the progenitors of O. Lamarckiana De Vries. Were they certainly flrst introduced through the cultures of Carter and Company, about 1860, or were they in England and perhaps on the sand hills of Lancashire previous to this date? Is it possible that the plants of Carter and Company came not from Texas but from some part of England, perhaps from the very sand hills of Lancashire? There certainly should be in British herbaria some evidence on these questions. It seems to be impossible to determine with exactness what are the forms under consideration in some of the descriptions published at dates of great importance to our problem, and that is why I have laid so much importahce upon herbarium material.

9 Origin of QEnothera Lamarckiana De Vries. 241 Thus Don' described in 1832 " (E. biennis" from "sand banks on the coast of Lancashire " and noted that it " is common in gardens and often escapes fi-om thence into rich waste ground," hut the statements " flowers large " and " delicately fragrant " are relative matters and we cannot be certain from this or other parts of the account whether the plants were nearest to Lamarckiana De Vries or to forms of biennis such as that from Holland (the biennis of Linnaeus). Lindley^ in 1833 gave an account of "(Enothera biennis var. grandiflora " and stated it to be " not uncommon in gardens." The figure of this plant shows petals drawn about cm. long, as large as those of Lamarckiana De Vries, but a basal or perhaps a rosette leaf is too narrow for Lamarckiana, nor will it do for the Dutch biennis or for grandiflora. The bracts are figured broad at the base and sessile as in both Lamarckiana and biennis, but the inflorescence with long internodes is not as in those species but is more like that of grandiflora; the bracts, however, are not those oigrandiflora. These contradictions are most puzzling, but may there not be specimens preserved at this period which will clear the obscurity. I am aware that the (Enothera floras in other parts of England offer opportunities for investigation that should not be overlooked in the study of the problems presented in this paper. 1 have, however, confined my suggestions to the remarkable assemblage on the sand hills of Lancashire for the reason that this region seems to be best known and to have been under observation for the longest period. ' Don, George. A General Sj'stem of Gardening and Botany, vol. 2, p. 685, ' ' Lindley, John. (Enothera hieiviis; var. graiidijlora. Edwards's Botanical Register, vol. 6, p. 1604, UNIVERSITY OF PENNSYLVANIA. March, 1913.

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