Notes on Cultivated Junipers

Butler University Botanical Studies Volume 14 Article 7 Notes on Cultivated Junipers Marion T. Hall Follow this and additional works at: https://digitalcommons.butler.edu/botanical The Butler University Botanical Studies journal was published by the Botany Department of Butler University, Indianapolis, Indiana, from 1929 to 1964. The scientific journal eaturf ed original papers primarily on plant ecology, taxonomy, and microbiology. Recommended Citation Hall, Marion T. (1961) "Notes on Cultivated Junipers," Butler University Botanical Studies: Vol. 14 , Article 7. Retrieved from: https://digitalcommons.butler.edu/botanical/vol14/iss1/7 This Article is brought to you for free and open access by Digital Commons @ Butler University. It has been accepted for inclusion in Butler University Botanical Studies by an authorized editor of Digital Commons @ Butler University. For more information, please contact [email protected]. Butler University Botanical Studies (1929-1964) Edited by J. E. Potzger The Butler University Botanical Studies journal was published by the Botany Department of Butler University, Indianapolis, Indiana, from 1929 to 1964. The scientific journal featured original papers primarily on plant ecology, taxonomy, and microbiology. The papers contain valuable historical studies, especially floristic surveys that document Indiana’s vegetation in past decades. Authors were Butler faculty, current and former master’s degree students and undergraduates, and other Indiana botanists. The journal was started by Stanley Cain, noted conservation biologist, and edited through most of its years of production by Ray C. Friesner, Butler’s first botanist and founder of the department in 1919. The journal was distributed to learned societies and libraries through exchange. During the years of the journal’s publication, the Butler University Botany Department had an active program of research and student training. 201 bachelor’s degrees and 75 master’s degrees in Botany were conferred during this period. Thirty-five of these graduates went on to earn doctorates at other institutions. The Botany Department attracted many notable faculty members and students. Distinguished faculty, in addition to Cain and Friesner , included John E. Potzger, a forest ecologist and palynologist, Willard Nelson Clute, co-founder of the American Fern Society, Marion T. Hall, former director of the Morton Arboretum, C. Mervin Palmer, Rex Webster, and John Pelton. Some of the former undergraduate and master’s students who made active contributions to the fields of botany and ecology include Dwight. W. Billings, Fay Kenoyer Daily, William A. Daily, Rexford Daudenmire, Francis Hueber, Frank McCormick, Scott McCoy, Robert Petty, Potzger, Helene Starcs, and Theodore Sperry. Cain, Daubenmire, Potzger, and Billings served as Presidents of the Ecological Society of America. Requests for use of materials, especially figures and tables for use in ecology text books, from the Butler University Botanical Studies continue to be granted. For more information, visit www.butler.edu/herbarium. NOTES ON CULTIVATED JUNIPERS MARION T. HALL Butler University I to Indianapolis, Indiana INTRODUCTION The genus Juniperus is the third largest in the coniferales, and its many species are not only widespread but also extensively cultivated. Several fac tors make the classifying of horticultural junipers both difficult and confus ing. First, the species are ill-defined since there are few good key characters and few qualitative characters. The numerous quantitative characters vary considerably. The characteristics of the reproductive organs, fruit characters, vary as much as those of the vegetative body. Secondly, natural hybridization at the species level is widespread and the recombinations are occasionally bizarre. Thirdly, horticultural selection is made by man without concomitant analysis of the variability of the populations at the site. Thus, it is often diffi cult to determine just which species a variety should be referred to. Fourthly, many of the selections are based on odd growth habit or aspect, low growing, cup-shaped, vase-shaped, upright, etc., and growth form is controlled in some cases by single gene differences, in others by polygenes. If the growth form is selected from a fairly pure population it is easy to label, if it comes from a hybrid swarm such a plant may be virtually impossible to properly associate with its progenitors once it is removed from the site. Because of these problems, selections of junipers to receive horticultural names should be accompanied by careful analyses of their origins. This is not so difficult as it sounds, at least not for a specialist in the group. The name Juniperus properly applies to those members of the family Cupressaceae with small, usually dark, fleshy, berry-like pistillate cones containing seeds without wings. The staminate and pistiUate cones may be borne on the same plant (monoe cious) or, more characteristically, on different plants (dioecious), even though the strongly dioecious species occasionally produce monoecious in dividuals, apparently at random. The junipers may very well be the most plastic of the cone bearing plants. They may be "forced" or trained to take innumerable shapes, many quite grotesque. I would estimate that the genus probably contains about forty species even though over sixty have been described. Geologically, the more primitive junipers are known from the Upper Cretaceous of New England and Green 2 73 land, while the more recent arid lands' junipers are known from the Pliocene does not satisfy m and the Pleistocene. The arid lands' types have probably evolved with the of the mature W( development of our modern deserts, apparently during the late Cenozoic. Junipems than to The majority of the species, the appressed scale·leaved ones, are character· based upon the (( istically found in semi·arid regions or in arid regions of mid-altitudes. The enchyma with a) I most primitive species, 1- drupacea LabiU., 1- Oxyced1"UJ L., and perhaps fields in horizont 1- fOelidiJJima Willd., are found in the arid areas of Asia Minor and from nodular; and 2) Morocco through Spain to the Caucasus. Other species are found from the overall differences Pamirs to Japan and Korea. In North America, junipers are found widely of 1- Oxycedmj oj from Canada and Alaska south through Mexico into Central America. The 1- OxycedrilJ fron most Widespread species is the circumboreaJ 1- commtmiJ L. The only species 1- drupat'etl, some extending into the southern hemisphere is the African 1- procera Hockst., junipers of southv which is an important forest tree at median to high altitudes from Ethiopia to northern Tanganyika. In the United States the most Widespread species is OXYCEDRUS. 1- virginiana L., especially so, if 1- scoptllorum Sarg. and 1- silh-ieola (Small) stipitate axes, the L. H. Bailey (barbademis of American authors) are considered as subspecies phylls decussate; 0 of it, a concept which I do not feel is justified by the data, however. their enlarged stig On each continent most of the species are centered about the Pacific side three, fewer by ab and are nearly equally divided between Eurasia and America. The present the base, eglandul distribution of Juniperus fits Buchholz' idea that the Pacific perimeter prob. buds scaly. ably represents the distribution center of the Coniferales during most of their There are nine 5 recent period of evolution. seven by a more COJ The conservative treatment of the genus calls for three sections: Caryoce dms L. (containir drus, Oxyced rus, and Sabina. The sections show structural series with regard Berth.), 1- brevif' to female cones and leaf types. The transitions are from more woody cones Hayata, 1- rigida S in section Caryocedrus to quite fleshy berry-cones in section O;,..-ycedrus, and 1- OxycedruJ, 1 from the acicular-type (awl shaped) leaves to reduced scale·type leaves in related with the lat section Sabina. 1- formosalla anI 1- commul1iJ~ 1- . SYNOPSES OF THE SECTIONS IN JUNIPERUS the section. CARYOCEDRUS. Microsporangiate strobili clustered 3 to 6 in a head, SABINA. Strobi spreading after anthesis, their axes stipitate; microsporophyJls 9 to 12, their strobili solitary; mi, connectives ovate acute, incurved at the apex; seeds joined into a thick glo. temate or opposite, bose woody 3-angled mass; leaves acicular. on the branches, g The single species, 1- drupacea Labill., may represent a relatively unsuc young plants free; cessful attempt at evolution toward a woody-coned arid lands' plant, or it The Sabina sedi, may represent the sole surviving species of a more ancient type of juniper. judged by quite cor This species is found in the eastern Mediterranean from the arid mountain in current taxonom sides of southern Turkey, to Syria, Lebanon, and the Peloponnesos. New and the Old ~ The evidence from wood anatomy and from gross morphology suggest more mesic habitat~ that Labillardiere (1791) was COrrect in placing this species in the genus In the Old World I Juniperus. Antoine's and Kotschy's evidence (1854) for the genus ArcetlthoJ ranean across Asia 74 known from the Pliocene does not satisfy me. Kaiser (1954) stated, "From the microstructural study obably evolved with the of the mature wood it is coucluded that this species is more similar to uring the late Cenozoic. Juniperus than to any other genus of the Cupressaceae. This conclusion is ved ones, are character based upon the combination of the following characteristics: 1) Ray par· ns of mid-altitudes. The enchyma with a) horizoutal walls relatively thide; b) abundant primary pit· ycedrus 1., and perhaps fields in horizontal walls; c) indentures regularly present; d) end-walls of Asia Minor and from nodular; and 2) \>(lood parenchyma with nodular transverse walls." The ies are found from the overall differences between J. drupacea in section Caryocedrus from those unipers are found widely of J. OxycedrllJ of section Oxycedrus are only slightly greater than those of to Central America. The J. OX'jcedJ'llJ from J. Jabina of section Sabina. As for the woody cones of umiJ 1.. The only species J.

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