NUMBER 77 JULY 1980 NORTH DAKOTA RIIIARCI RIPORT A Summary of the Synonomy of Leafy Spurge NORTH DAKOTA STATE Ul':TVERSITY NOV;) - 1980 SERIALS DEPT. Donald S. Galitz Professor of Botany North Dakota State University LIBRARY AGRICULTURAL EXPERIMENT STATION NORTH DAKOTA STATE UNIVERSITY FARGO. NORTH DAKOTA 58105 l­ I r I.e ~ I L I l­ I t I • I I. I I­ I r A SUMMARY OF THE SYNONOMY OF LEAFY SPURGE Dorrald S. GaNtz Professor of Botany North Dakota State University Investigators who have worked with members of in southwestern Minnesota. It is suggested by several the family of plants known as the spurges and parti­ authors that the original source of seed for the plants cularly those treated in this report are aware of tne occurring in North America was contaminants in variation in form which is exhibited by specimen ballast seed brought from Eurasia. Batho (1931) collections from different localities and are suggested that leafy spurge was a contaminant in oat immediately confronted with the confusion as to its seeds brought to southwestern Minnesota from proper nomenclature. Historically, this group of southern Russia around 1890. The first reports of plants has been combined to make up a single group leafy spurge in North Dakota are dated 1909. At a and then subdivided into several groups a number of recent symposium on leafy spurge held in Bismarck, times resulting in the appearance of several synonyms NO (1979), D. L. Noble reviewed the distribution appearing in the literature. Although it is not a weed of spurge in North America, citing Moore (1958) and of significant economic consequence in its Eurasian Harris and Alex (1971) as reporting spurge to occur origin, leafy spurge has lived up to all expectations in every Canadian province, except Newfoundland, of becoming a severe weed problem in numerous and Reed and Hughes (1970) as reporting a distribu­ areas of the U. S. and Canada during the 150 years of tion similar to that of Hanson and Rudd (1933) with its reported existance in North America. a shift in the center of infestation to the west at a point near Wolfpoint, Montana, then including 25 Leafy spurge has been a persistant weed, defying states and 451 counties. Dunn (1979) has since re­ the various control programs available to date and ported a study of the distribution of several species consequently has been documented as increasing the of Euphorbia indicating a still further migration of range of its distribution and degree of infestation. the infestation westward. Because of its persistance Therefore there has been considerable revival of as an aggressive perennial throughout the upper half interest t~ support research on the spurges and in of the United States and most of Canada, the particular the plant we call leafy spurge. It becomes taxonomy of this plant of Eurasian origin has been appropriate then, in considering this plant and the the center of several treatments. problems it causes, to review its natural history and its pedigree. This report deals specifically with the In spite of the considerable amount of literature latter of these two. Since more than one scientific available, as in the works of Stevens (1922), Hanson name is being used in this region to designate leafy and Rudd (1933), Barnett and Hanson (1934) and spurge, such a review may help in the adoption of a Batho (1938), which deal with local forms of leafy uniform use of nomenclature or at least assist investi-· spurge, there !i6f:ms to be little agreement as to gators to be cognizant of the basis for the different whether to call this weed Euphorbia esula L., E. names that have been used over time. virgata Wald. & Kit.,. or as more recently introduced by Croizat (1947), E. podperae Croiz. Part of the RANGE confusion lies in the fact that some investigators have not been able to recognize a difference between The first reported collection of leafy spurge in the what has been described as E. esula and E. virgata United States is that of William Oakes in Massachu­ whereas others have claimed to be able to distinguish setts in the year 1827. Twenty years later in the between these plant types. Considering the fact that first addition of Asa Gray's manual, leafy spurge was the basis for the confusion in nomenclature is due to described as a weed likely to become troublesome. the conflicting literature which exists in reviews of Just over 100 years later, in 1933, Hanson and Rudd E. esula, it is relevant to review on a chronological reported the range of leafy spurge to include 20 basis the development of the different names which states in the United States, and parts of southern have been proposed with the hope of coming to a Canada. At that time it already reached from upper conclusion as to what might be the most acceptable New England including Maine, acr:.oss the northern name to use at the present time. half of the United States to Idaho and Washington, w!th the greatest concentration of infestation being 2 SUMMARY OF SYNONOMY OF LEAFY SPURGE •• •••,••.1•••• W.bb.l a.rth. <__• ___ E • ••",".,,'c. Lmk. (1788)_ I Europe I So. African sp. A ~ 1".,••,•••plt,II•••••,,,••,•• 0111. (1732)- ~ " ••___.D,". , ----------------.• :I I I , • Crantz (1766) I Brown (1915) ", I I \. I I 'I I I E • ••",".,,'c. L. (1753) ___________________j-> E . ••,,1. L 01 Europe _____ I Europe ----------- , • Cro,zat (1945) . G , ..0. ,, E. obl"oltoll. Poor (1811) Af----- , g c , Polr.(1811l . 2 Q g , • Webb & Berlh.( 1836-50) , Bol••.( 1862) ... :;;· co'" o Z E••'.'8".'. Flsch.1 e x Link ____ Co) -~--------> E. rl,••t. Oe.I.( 1804)-" - --__] c Ealtern Rueaia o (; • Wheel.r (1838) :I QI E. rlrl.'. Wald.1 Kit. (1805) A ___________________________ _ _ _______.t QI '" E. po"p.,•• eroiz.( 19471 Hungary G •• ••",. L. of the U.S. _________ • ~• ~ •• Croln\( 1945) •• ,.,.,••" ••• Pax (180S) _ ----] England A a •••d on collections. E. I.,a'II."••• Podp.(11122)." -- - ___________ _ Conlld.r.d .1 lubopecl.1 (ecotypeo) 01 the I8me planl type (opecl.o) •. poflp.,o. Crolnt 11147 in Ihe oub"enuo IV ••",•• Rlchardoon (1I1S8) . Ch.cho.'o••k, • ---------.!. • No diltinction between- apecimenl or d ••criptiona. .. Hum.roUI Iynonyml in IIteratur•. FIGURE 1 ~---- .....-~'1 1 SYNONOMY tion of E mauritanica is based on diagnostic notes. In 1766 Crantz ind icated that the Linnean E. mauri­ With the establishment of the genus Euphorbia tanica is probably based on Dillenius' descriptions of in 1753, Linnaeus rejected the distinction that earlier Tithymalus aphyl/us mauritaniae,. Tithymalus Dill. herbalists had made between the plant groups and Euphorbia mauritaniae Dill. dated 1732. Accor­ Chamaesyce, Tithymalus, Euphorbium and Peplis. ding to Croizat, Dillenius' illustrations of E. Since that time this genus has been subjected to mauritaniae are so explicit that modern taxonomists considerable controversy with some investigators on one hand using Euphorbia in a broad sense and After Richardson (1968): Jthers dividing it into various sections or groupings lf genera or subgenera. Family: Euphorbiaceae 283 genera 1600 species ~ 1 The relationships of the various recorded treat­ Genus: Subgenera: # Species lnents of plant types is summarized in Figure 1. , Euphorbia Chamaesyce 12 Agalomia 3 ~ In 1872, Boissier did a revision of the entire genus Poinsettia 2 lIl:uPhorbia, incorporating the writings of Englemann. Esula 4 spathulata • ~gain in 1931 Pax and Hoffman attempted a major podperae (includes types) turvey of the genus in which they established a single esula L. nus which was subsequently divided into nine virgata Wald. and Kit, • ctions with an estimated 1600 species. Croizat intercedens Pax. ~n his review in 1945 cited several other workers who cyparissias ave dealt with parts or all of the genus Euphorbia, robusta 'I aking particular note of the major works of Norton + 2 varieties 'j(1900) and Wheeler (1941). The most recent treat­ :1ment to include all of the members of the genus FIGURE 2 1Euphorbia prior to that of Croizat's in 1945 was "J Rydberg (1932), who divided the genus into six genera with 24 species. Later treatments of this J.. genus in the United States are for the most part 'i incomplete works which dealt primarily only with cannot distinguish it from E obtusifolia Poir. and 1 those species which occurred and were reported with­ therefore Crantz's conclusion that Tithymalus Dill. ~ in a state or region. Croizat's detailed review of is the appropriate reference for Linnaeus' publica­ .. Euphorbia was written using the fairly classical tion of E. mauntanica is correct. It should be men­ ~. approach whicK' recognizes distinct groupings as tioned that Lamarck did not publish an E. mauri­ subgenera of a very diverse genus Euphorbia, This fnYl;rn nf hi" n'Aln hIlt r",thor 'AI"''' roforring to Correction Page 4, col. 2, after line 14; nica Euphorbia rnauritaniae Dill. Since this is based on rica, 804 Dillenius' Tithymalus, it is concluded .. lOrb was jied )Iet( by ----onneaus' pUOlicatlon or J!.. maurztanzca In the year tsolsSler In 1802, all Of Whom COnCTlJOe<r that E. 1753. According to Croizat (1945) this presentation virgata was not distingu ishable from the E. obtusifolia of E. mauritanica is hazy and over-inclusive, with of Poiret. Since the date for E. virgata preceeds that references to a number of poorly noted entities which of E. obtusifolia the former should be the proper has been cultivated for years in European gardens. name. Since E. mauritanica L. which is based on He goes so far as to suggest that E. mauritanica so Tithymalus Dill. is also E. obtusifolia, that makes conceived probably includes a number of non­ E virgata Desf.