hhh Soc compliments ie Le ( fir Uniworsdy freda , . wey Zz fLmertiranm . Drane. yy a ea: a r ar ter NG iy 137 A Is : Ni le ~e BzeQN — : \ Aum) Ue ~Gibson- inven 45 ae (owe Se With the Compliments of the Delegates of the Prefs Oxford hun pies Wh MV vy f i i 1 \ } i HANDBOOK OF FLOWER POLLINATION BASED UPON HERMANN MULLER’S WORK ‘THE FERTILISATION OF FLOWERS BY INSECTS’ BY DR. PAUL KNUTH FORMERLY PROFESSOR IN THE OBER-REALSCHULE IN KIEL, AND CORRESPONDING MEMBER OF THE BOTANICAL SOCIETY DODONAEA IN GHENT TRANSLATED BY J. R. AINSWORTH DAVIS, M.A. TRINITY COLLEGE, CAMBRIDGE VOLUME I INTRODUCTION AND LITERATURE WITH 81 FIGURES IN THE TEXT OXFORD AT THE CLARENDON PRESS 1906 OK S21 Peet 1906 v.| HENRY FROWDE, M.A. PUBLISHER TO THE UNIVERSITY OF OXFORD LONDON, EDINBURGH NEW YORK AND TORONTO TO THE MEMORY OF CHRISTIAN KONRAD SPRENGEL FORMERLY RECTOR OF THE GREAT LUTHERAN TOWN-SCHOOL IN SPANDAU BORN AT BRANDENBURG ON THE HAVEL IN 1750 DIED AT BERLIN ON APRIL 7TH, 1816 AND DR. HERMANN MULLER FORMERLY PROFESSOR IN THE REALSCHULE AT LIPPSTADT IN WESTPHALIA BORN AT MUHLBERG IN THURINGIA ON SEPTEMBER 23RD, 1829 DIED AT PRAD IN THE TYROL ON AUGUST 25TH, 1883 CurisTIAN KonrapD SpRENGEL and HERMANN MULLER were characterized by untiring diligence and ardour for research, incomparable powers of obser- vation, and extraordinary acuteness in the interpretation of the phenomena of Flower Pollination. With this was united in a conspicuous degree the ability to describe their discoveries in a most admirable manner. Their fundamentally important works on Flower Pollination are now, therefore, an inexhaustible source of instruction and enjoyment, as they must always be. This book, which shows the present position of the Science of Flower Pollination, is dedicated to the memory of these two great investigators. Salant Na is ane oarye ae | Beau et Pas Fe ae sO beh, saugihanhh ca A bs mM: i ay a) fee il ny ALLA Ae tA “bath tf vie mi 4) waa sh LOG i MA: t aM Beno v mt heen vale oN He tiwytsh wal eed, Ae, Ween seh wth, ii iti i Vy Lay a Ps) ny a aba CON | i; bay a bat ie * i ihe z Oe et nyc: LM at at ea ae tS ; ; TEessiivad ith ind, eat, ym he NY | wiped y! “dh ays Bry, 2 bef, ifn! 1, et afi ty Pu (5 eet Not ake ‘A oe oe 4 att nerd med ts " Metin leeas pith “fall aby AO UoM, i) CEO Mae ie ra ith py Wey S4y, ad 2 j aber ane ath Baslatr, i | alah Aya Mnuee 7 TOES Ri snags hitncin Goe IGE, Bayt AP LLORGETY s a Etbnenatd stn Path A sin Tike 4antGks Pia whan lit Anwaah ae cA aGr ciel sh te a Kaye @ Ay eee) let Chai ii He Haul apd h Ent) WOM sa Baim vig’ ser si viento sae Y BOTANICAL CLUB. URRE ett v5 | / °¢y AUTHORS: PREFACE TWENTY-FIVE years have passed since the appearance of Hermann Miiller’s admirable book on ‘The Fertilisation of Flowers by Insects and their Reciprocal Adaptations!.’ It has long been out of print, and it seemed to me to be worthy of republication with notes, like the funda- mental work of Christian Konrad Sprengel: Das entdeckte Geheimnis der Natur im Bau und in der Befruchtung der Blumen (Berlin, 1793), which I brought out some years ago in Ostwald’s Klassiker der exakten Natur- wissenschaften (vols. xlviii-li)*. The further, however, I entered into the. subject, the more I became convinced that the observations of later investigators, following in the steps of Miiller during the last two decades, and developing this branch of botany in a remarkable manner, have given us such abundance of new material that the necessary notes and additions would considerably exceed the original contents of Miiller’s book. I accord- ingly resolved to write an entirely new work, founded upon Hermann Miiller’s ‘ Fertilisation of Flowers by Insects,’ after satisfactory arrangements had been made with his representatives. The fruitfulness of the investigations made during the last two decades on the relations between the structure and environment of flowers, and the widening of the circle of those who take an active part in these investigations, have added to the difficulty of the task of collating the enormous quantity of available material. To accomplish this it was necessary to devote three years of uninterrupted labour, during which there appeared numerous, and in part extremely important, new publications on Flower Pollination, which had to be taken into consideration. Literary activity, however, quite unlike scientific investigation, demands a conclusion, and therefore it seemed to me inexpedient to delay any longer the publication of the work. The memoirs that appeared on the subject during the printing of my work were considered as far as possible, especially when they afforded a solution of contradictions occurring in the statements of different observers in regard to the same flower. During the whole time spent in writing this work, I have been constantly engaged 1 ‘Die Befruchtung der Blumen durch Insekten und die gegenseitigen Anpassungen beider, Leipzig, 1873, Wilhelm Engelmann. English Translation by D’Arcy W. Thompson, 1883. ? Leipzig, 1894, Wilhelm Engelmann. vi AUTHOR’S PREFACE in trying to clear up such contradictions by my own investigations, and in endeavouring by my own research to increase our knowledge of floral adaptations, and of the visitors to our flowers, so that this book will seldom be consulted in vain by any one who desires information of this sort with regard to our indigenous or cultivated plants. It would, however, have been impossible for me to bring the work to a conclusion in the comparatively short space of three years, if I had not been able to make use of several excellent recent works on Flower Pollination, especially those of Kerner, Loew, and Ludwig, and unless I had been given most friendly assistance by numerous flower specialists, and by my other botanical and entomological friends, who were always ready to help me in every possible way. I therefore take this opportunity of renewing my thanks to all these, especially to the following gentlemen :— D. ALFKEN in Bremen, O. APPEL in Wiirzburg, J. BEHRENS in Karlsruhe, F. BUCHENAU in Bremen, J. HENRY BURKILL in Kew, C. CORRENS in Tiibingen, F. DAHL in Berlin, K. v. DALLA TorRE in Innsbruck, F. DELPINO in Naples, O. EkSTAM in Troms6, TH. FRIES in Upsala, A. GLOY in Kiel, A. HANSGIRG in Prague, J. H. HART in Port of Spain (Trinidad), F. HILDEBRAND in Freiburg i. B.. A. KERNER VON MARILAUN in Vienna, O. KIRCHNER in Hohenheim, A. KNEUCKER in Karlsruhe, E. LOEW in Berlin, F. LUDWIG in Greiz, J. MACLEOD in Ghent, P. MAGNUS in Berlin, TH. MEEHAN in Germantown, Philad.(U.S.A.), F. MULLER (f) in Blumenau (Brazil), G. NATHORST in Stockholm, F. PLATEAU in Ghent, K. RECHINGER in Vienna, CH. ROBERTSON in Carlinville, Ill. (U.S. A.), CHR. SCHRODER in Itzehoe, A. SCHULZ in Halle, G. F. SCOTT-ELLIOT in Glasgow, P. STOLZENBURG in Kiel, J. URBAN in Berlin, C. VERHOEFF in Bonn, E. WARMING in Copenhagen, and C. WARNSTORF in Neu-Ruppin. I also carried on at times a very extensive correspondence on the subject of this book, especially with Herren ALFKEN, APPEL, KIRCHNER, LOEW, and LUDWIG. It was my intention to embellish this work with portraits and auto- graphs of all the most distinguished specialists in flower pollination, but it was impossible to obtain photographs of all. I have, therefore, confined myself to giving portraits of those to whom we are indebted in the highest degree for the advancement of the subject: i.e. J. G. Kdlreuter, Charles Darwin, H. and F. Miiller, F. Delpino, F. Hildebrand, and S. Axell. Unfortunately no portrait of the grand master of our science, Christian K. Sprengel, was to be had. There is given, therefore, in the absence of this, a reduced fac- simile of the characteristic title-page of his book ‘ Das entdeckte Geheimnis.’ I have endeavoured, so far as possible, to make use of the original memoirs of authors in recounting their observations, and have also, when practicable, adhered to the terms used by them, but I was not able to see all the original works on Flower Pollination, in particular the more recent AUTHOR’S PREFACE vii works in Italian and French. I have, therefore, frequently been obliged to content myself with information derived from references in the ‘ Botanischer Jahresbericht’ (1883 to 1895), and the ‘Botanisches Centralblatt.’ Some works had to be left altogether unnoticed, as I was not able to get any information as to their contents. A few have no doubt escaped me altogether, but I hope to have attained at least relative completeness. In course of the preparation of the material, it appeared that the work would be too comprehensive for a single volume. I determined, therefore, to publish in the following divisions.— 1. Introduction and Literature. 2. The Observations in Flower Pollination hitherto made in Europe and in the Arctic regions. | (2) Ranunculaceae to Compositae. (4) Lobeliaceae to Coniferae. 3. Observations in Flower Pollination made outside Europe. In the introduction, I have given, in the first place, a short survey of the historical development of flower pollination. In doing this I was chiefly concerned with introducing the most prominent facts in this sphere of research, especially the labours of Kolreuter and Sprengel, and the development of the floral theory which is associated with the names of Sprengel, Knight, Darwin, Hildebrand, Axell, Delpino, and Hermann Miller. This short survey will sufficiently elucidate the present stand- point of flower pollination. I was freed from the necessity of exhaustively considering the historical development of this science by the excellent work of E. Loew, ‘Einfiihrung in die Bliitenbiologie auf historischer Grundlage’ (Berlin, 1895). In this work the subject is treated at great length, and accordingly Loew’s ‘Introduction’ forms a necessary sup- plement to my handbook. In the second division of the introduction, besides my own writings and those of Hermann Miiller, I have made most use of the works of Charles Darwin, F. Delpino, W. O. Focke, F. Hildebrand, A. Kerner, O. Kirchner, E. Loew, F. Ludwig, H. von Mohl, Fritz Miiller, Christian K. Sprengel, Aug. Schulz, and E. Warming ; and from these an idea of the present position of flower pollination is obtained. The lists of self- sterile, self-fertile, and cleistogamous flowers may not, however, be quite complete. The compilation of the literature of flower pollination was made much easier by the following: ‘ Bibliography’ in D’Arcy W. Thompson’s transla- tion of Hermann Miiller’s ‘Befruchtung der Blumen durch Insekten’ (‘ The Fertilisation of Flowers,’ London, 1883, pp. 599-630), which contains most references to literature up to the year 1882; MacLeod’s ‘ Lijst van Vill AUTHOR’S PREFACE Boeken, Verhandlingen,enz. omtrent de bevruchting der Bloemen,van 1883 tot 1889 verschenen’ (Bot. Jaarb. Dodonaea, Ghent, ii, 1890, pp. 195-254); and lastly, the ‘ Litteraturverzeichniss (1883-93)’ in Loew’s ‘ Bliitenbiologische Floristik’ (Stuttgart, 1894, pp. 4-18). I have supplemented these notices of the literature especially by working through the references published by v. Dalla Torre in Just’s ‘Botanischer Jahresbericht’ from 1883 to 1895; and placed at my disposal by the author, and also the ‘ Neue Litteratur’ in the ‘Botanisches Centralblatt’ from 1880 till October 1, 1897. An appendix gives the works on flower pollination that have appeared during the printing of the first volume, up to April, 1898. Here also are named a few of the oldest works on the sexuality and the fertilization of flowers, which I had at first overlooked, as well as the literature on perception of form and colour, and on the olfactory and visual powers of insects, mostly from H. J. Kolbe’s ‘Einfiihrung in die Kenntnis der Insekten’ (Berlin, 1893). The bibliography as here presented should be moderately complete, but I cannot in every case vouch that the titles are absolutely correct, as the original works were not always available, and some of the sources on which I had to depend contain numerous printers’ errors. The works that appeared during the preparation and the printing of this handbook have been, as I have already said, taken into consideration as far as possible. The notices which J. Behrens has published on Kolreuter (Verh. Natw. Ver., Karlsruhe, 1894), and the important investiga- tions of F. Plateau which have been published under the title ‘Comment les fleurs attirent les insectes’ (Bul. Acad. roy., Bruxelles, 1895-7), are discussed in an appendix to the introduction. The second volume contains descriptions of the structure of flowers, and notices of the flower visitors hitherto observed in Europe and in the Arctic regions, and of their relations with the flowers they visit, following closely the accounts of the observers who first described the facts. I have, in particular, left unaltered, so far as possible, Hermann Miiller’s descrip- tions of flowers, as an account by this investigator cannot be safely modified: I have, however, usually made slight abbreviations. While descriptions of the structure of flowers belonging to indigenous European species have generally been retained intact, and their visitors given as fully as possible, I have only briefly indicated observations made in Europe on cultivated but non-indigenous plants. A fuller description will be given of these in the third volume of this work, but they could not be altogether omitted in the second, as it was impossible to distinguish sharply between indigenous, acclimatized, and cultivated species. I have, therefore, given short accounts of all observations made in Europe on plants that are not indigenous. On the other hand, I have left unnoticed all investigations which, though described in European periodicals, refer to extra-European regions. It is obvious that in dealing with such an AUTHOR’S PREFACE ix immense amount of material, I must now and then have overlooked observations on the flower pollination of foreign species. But in such cases these will be found in the third volume. On the other hand, a comparative review has been given in the second volume of Ekstam’s accounts of flowers and their guests in Nova Zemlia, the observations of Lindman on floral structure and pollinating agents made in the Dovrefjeld region of the Scandinavian Highlands, the similar researches of Warming with regard both to this region and Greenland, and the works of Aurivillius on insect life in the high North. Only the most important of the very numerous descriptions given in Kerner’s ‘Natural History of Plants’ have been referred to in the second volume of this handbook, as most of them are briefly mentioned in Volume I. A complete purview of the very extensive material gathered together in the ‘Natural History of Plants’ has not been attempted, as Kerner’s work is very widely known. In describing the natural orders of plants from the point of view of flower pollination, the indigenous European forms are dealt with at greatest length ; extra-European species are referred to only occasionally, as they are reserved for treatment in the following volume. I have endeavoured in this handbook to establish generic characters in flower pollination, as I previously did in my work ‘Blumen und Insekten auf den nordfriesischen Inseln’; yet this has not been practicable in all cases, for the observations on some species were too imperfect. It was not always possible with the resources at my disposal to determine the authors of names of species; and as reference to the biologist in whose work I found a name did not always furnish the desired information, a few species of plants have had to remain without an author’s name. Besides observations on insect-visits recorded in works specially de- voted to flower pollination, there are also included records from numerous purely entomological works and treatises, so far as these leave no doubt as to the species of plant concerned’. Among these works are those mentioned in the bibliography (vol. i, p. 212) under the names of the following authors :— Alfken, André, Aurivillius, Bonnier, Cobelli, v. Dalla Torre, Dours, Ducke, Entleutner, Frey, Frey-Gessner, v. Fricken, Friese, Gerstaecker, Handlirsch, Hoffer, Holmgren, Koch, Kohl, Krieger, Leege, Marquard, Morawitz, Nylander, Pérez, Redtenbacher, Réssler, Saunders, Schenck, Schletterer, Schiner, Schmiedeknecht, Schultess - Rechberg, Sickmann, Smith, Thomson, and Wiistnei. 1 Ambiguous references are neglected,—such as: ‘ Especially in som species of Centaurea and Sedum? An exception is made, however, in the case of Sa/ix, as experience shows that insects visit the various species indiscriminately. x AUTHOR’S PREFACE Some of these works, for instance those of Alfken, Dalla Torre, Frey, Friese, Hoffer, Krieger, Morawitz, Schletterer, and Sickmann, contain in places an amazing amount of material for use by the flower specialist, and frequently afford the only available information as to visitors to flowers. Others, on the contrary, as, for instance, André’s work, which is in many volumes, contain only a few useful notices. There are numerous other entomological works, especially in French and Italian, which might have been referred to, but to have done so would have greatly increased the toil of compilation; and it is questionable if the result would have repaid the labour. Some, indeed, of the works that were looked into contained no useful information at all, as, for instance, Aurivillius (Gronlands insektfauna ; Vet.-Ak. Bih., Stockholm, Vol. xv, Ser. 4, Nr. 1, pp. 1-33) and F. Chevrier (Description des Chrysides du Bassin du-Léman, Geneva, 1862) 1. Herr D. Alfken has placed at my disposal his valuable observations on the visits of insects to flowers in the neighbourhood of Bremen. Some observations of Hans Hoppner, that also refer to the neighbourhood of Bremen, are added. Further, Herr Alfken has communicated to me, in addition to his previously published observations on the Island of Juist, a number of new ones. Besides my own observations on the visits of insects to flowers, and in addition to those of Borgstette, Buddeberg, Burkill, Cobelli, Darwin, Delpino, Ekstam, Heinsius, Lindman, Loew, MacLeod. Hermann Miller, Plateau, Rathay, Ricca, Schneider, A. Schulz, Scott-Elliot, Sprengel, Verhoeff, de Vries, Willis, and Wittrock, there is a very considerable mass of work containing material useful in studying flower pollination ; so that here again only a relative independence can be claimed. The ‘tedious’ lists of visitors, in which thousands of individual observations are set down, form the indispensably necessary statistical material upon which to base our knowledge of the relations subsisting between groups of flowers and insects. They afford an insight into the connection between the structure of flowers and the anatomical characters of insects ; they tell us that everywhere flowers are sought out in preponderating majority by such insects as are modified in adaptation to them. I reserve this statistical material for working up afresh. It must be admitted that in the enumeration of visitors, the record 1 There were also no observations on flower pollination in works that I looked through by M. J. Pérez (Contributions 4 la faune des Apiaires de France, II* partie, Parasites. — Actes soc. linn, Bordeaux, 1883) and by Ruggero Cobelli (Gli imenotteri di Trentino, Fasc. I: Formicidae, Rovereto, 1887; Fasc. II: Tenthredinidae, Apidae, Chrysididae, Pompilidae, Scoliadae, Mutillidae, Sapygidae, 1891; Fasc. III: Vespidae. — Sphegidae, 1893; Fasc. IV: Evanidae, Cynipidae, Chal- cididae, Proctotrupidae, Ichneumonidae, Braconidae, 1897). AUTHOR’S PREFACE Xi of the way in which the visit is effected is frequently not sufficiently detailed. There is often a similar lack of detail with regard to the numbers of visitors to a species and the constancy of their visits. This, however, is due to the fact that the authors whose observations are embodied have not given particulars. In this handbook an attempt is made to give a relatively complete account of visitors to the various species of plants, so as to determine their circle of guests, and therefore all records, however imperfect, are cited. For the most part, however, the kind of activity, and the numbers and constancy of the insect visitors, are indicated by the following contractions :—‘skg.’ (sucking), ‘nect-lkg.’ (nectar-licking), ‘ po-cltg.’ (pollen-collecting), ‘ po-dvg.’ (pollen-devouring), and ‘freq.’ (frequent). From these symbols one may almost always recognize distinctly whether the visitors were acting as pollinators or not, and a more exhaustive account of the behaviour of the insects during their visits to flowers of simple structure is therefore, in most cases, quite unnecessary. Moreover, it would greatly add to the size of this already voluminous work. Such details have only been given in the case of flowers with distinctly complicated adaptations of the floral leaves, where a more exhaustive description of the relations seemed necessary. An effort has been made to arrange the observations according to the geographical position of the districts in which they were made, though this could not always be carried out consistently. In naming and arranging the insects I have made use of the following works.— C. G. DE DALLA TORRE. Catalogus Hymenopterorum hucusque descr. syst. et syn. Leipzig, 1892 on. (So far as published.) J. R. SCHINER. Fauna Austriaca. Die Fliegen (Diptera). 2 Bde. Wien, 1862 and 1864. JOS. MIK, Verzeichnis der Arten-Namen, welche in SCHINER’S Fauna Austrica enthalten sind. Wien, 1887. A. PuToN. Catalogue d’Hémiptéres de la Faune paléarctique. 3° éd. Caen, 1886. C. BRUNNER V. WATTENWYL. Prodromus der europdischen Orthopteren. Leipzig, 1882. G. SEIDLITZ. Fauna baltica. Die Kafer der deutschen Ostseeprovinzen Russlands. 2. Aufl, Kénigsberg, 1891. (Where this work did not suffice the two following were used.) G. SEIDLITZ. Fauna transsilvanica. Die Kafer Siebenbiirgens. Ké6nigsberg, 1887. M. GEMMINGER et B. DE HAROLD. Catalogus Coleopterorum hucusque descriptorum synonymicus et systematus. Miinchen, 1868-76. O. STAUDINGER und M. WocKkE. Katalog der Lepidopteren des europdischen Faunengebietes. Dresden, 1871. M. Rostock. Neuroptera germanica. Zwickau, 1888. The visitors of flowers are arranged alphabetically in orders, families, genera, and species. A revision of the insects observed by me visiting flowers, as detailed in earlier writings, has been undertaken by the fol- lowing :—D. Alfken, Bremen; A. Costa, Naples; F. Dahl, Kiel; V. von Xil AUTHOR’S PREFACE Réder, Hoym (Anhalt); C. Verhoeff, Bonn; W. Wiistnei, Sonderburg (Alsen). To these gentlemen I here offer my renewed thanks. On the other hand, the records of flower visitors are not taken from works which deal with the flower pollination of a definite, circumscribed region. The following are among these.— HERMANN MULLER, Alpenblumen (Leipzig, 1881), P. KNUTH, Blumen und Insekten auf den nordfriesischen Inseln (Kiel and Leipzig, 1894), Te boy De Pyreneeénbloemen en hare bevruchting door insecten (Ghent, 1891), and J. MACLEOD, De bevruchting der bloemen in het Kempisch gedeelte van Vlaanderen (Ghent, 1893 and 1894)?. The observations set forth in these writings are, for the most part, only referred to in this handbook, and the flower visitors that are recorded are only indicated by reference to the chief groups to which they belong. These books are necessary for every student of flower pollination, to supplement the facts narrated in this handbook. The extraordinarily heavy and lengthy task of editing the lists of visitors was undertaken by D. Alfken of Bremen, with praiseworthy readiness. He has had the pleasure of receiving help in this work from the following gentlemen.— . FRIESE in Innsbruck (Bees), KoNow in Teschendorf (Saw-flies), . KRIEGER in Leipzig (Ichneumons), . KUNNEMANN in Oldenburg (Beetles), . VON RODER in Hoym (Flies), . SCHLETTERER in Innsbruck (Digging-wasps), and . STAUDINGER in Dresden-Blasewitz (Lepidoptera). op