Volume 47 Number 1 Winter 1987 Amoldia (ISSN 0004-2633; USPS 866-100) is published quarterly, in winter, spring, summer, and Page fall, by the Arnold Arboretum of Harvard University. 2 A Diversity of Hollies Subscriptions are $12.00 per calendar year Polly Hill domestic, $15.00 per calendar year foreign, payable in advance. Single copies are $3.50. All remittances must be in U. S. dollars, by check drawn 14 RESEARCH REPORT on a U. S. bank or by international money order. Send subscription orders, remittances, change-of- Clonal and Age Differences in the address notices, and all other subscription-related Rooting of Metasequoia glyptostroboides communications to: Helen G. Shea, Subscriptions Manager, Arnoldia, The Arnold Arboretum, Cuttings Jamaica Plain, MA 02130-2795. John E. Kuser Postmaster: Send address changes to: 20 BOTANY: THE STATE OF THE ART Amoldia How Development’s Clock Guides The Arnold Arboretum Evolution ’" Jamaica Plain, MA 02130-2795. ° John W. Einset Copyright © 1987, The President and Fellows of Harvard College. 26 BOOKS Edmund A. Schofield, Editor Peter Del Tredici, Associate Editor Helen G. Shea, Subscriptions Manager Manon D. Cahan, Editorial Assistant (Volunteer) Jan Brink, Research Assistant (Volunteer) m , Arnoldia is pnnted by the Office of the University Publisher, Harvard University. Front cover.~ A fruiting branch of Ilex opaca Aiton. From a glass transparency in the Archives of the Ar- nold Arboretum. (See page 2.) Inside front cover: The buttressed trunk of a Metasequoia glyptostro- boides H. H. Hu & Cheng tree growing in the Bailey Arboretum, Locust Valley, New York ("Bailey 1"~. Photograph by John E. Kuser. (See page 14.) Inside back cover: Ilex pedunculosa Miquel growing in a schoolyard in Kamo, Kyushu, Japan. This photo- graph was taken on March 4, 1914, by Ernest H. Wil- son. From the Archives of the Arnold Arboretum. (See page 2.) Back cover: Ilex cornuta ’Bmfordii’, a vigorous holly cultivar and one of the parents of Ilex ’Lydia Morris’. Photograph by Donald Wyman. (See page 12.) Sii~iw of North America Tab XLV A Diversity of Hollies Polly Hill Decades of work on Martha’s Vineyard have yielded valuable insights into the hardiness of hollies-and numerous new cultivars as well Hollies (Ilex spp.) have long been popu- cribe grow at "Barnard’s Inn Farm," our lar. During the festive Christmas season summer home on Martha’s Vineyard, their bright berries and shiny, prickly Massachusetts, an island situated in the leaves are enjoyed widely. But most peo- Atlantic Ocean, south of Cape Cod. A ple are unaware of the great-and few of the hollies are native to the Vine- increasing-diversity of hollies available yard and the adjacent coastal mainland, for a variety of landscape situations. but others hail from Europe or Asia. Only The beauty of hollies deserves those hardy in Zone 6 can adapt and ma- more than passing admiration. In fact, ture, but my collection has grown in the when one becomes aware of their varied last twenty-five years, until now there are charms, holly collecting can become an upwards of one hundred thirty taxa. addiction. Their flowers, mostly white, The soils on Martha’s Vineyard are small, inconspicuous, and sweetly are strongly acid, nutritionally poor, dry, scented in May, when most species and sandy. The hollies endure gales and come into flower. Their leaves have an temperatures as low as -10 F in winter unlimited variety. Some hollies have and dry soils in summer. Greatly in their spiny, others have spineless, leaves, favor are the humid sea air and the per- while still others have both spiny and fect soil drainage. spineless leaves. The leaves may be long and slender, short and fat, thin or leathery, round, elliptic, serrated or llex opaca entire, quilted or smooth. Their fruits, borne only by female plants, may be red, To the average Easterner, the word orange, yellow, black, or greenish white "holly" suggests Ilex opaca Aiton, a tree to pinkish white. Many species of holly native from eastern Massachusetts to are beautiful for their branching, which Florida and west to Missouri and Texas. can be layered, upright, pendant, or It grows wild in Delaware and Maryland twiggy. near our home. In the 1930s the Farmers The hollies I know and will des- Market in downtown Wilmington provided us with sprays for Christmas and a hand- made wreath for our front door, clusters Flowering and Fruiting Branches, Flowers, and of live berries decorating the wreath. Fruits of Ilex opaca Aiton. Drawing by Charles E. Faxon. Onginally published in Charles Sprague Sar- Now, in the 1980s, one can spot holly gent’s Silva of North America (Volume 1, 1891).). trees along the highway, but the large 4 females are gone, and only an occasion- repetition, we built a barn owl nest in our al male will be left undisturbed; both the big barn; mice, voles, and baby rabbits holly wreath and the Farmers Market are are now kept in check most satisfactorily.) of the past-spent. At Barnard’s Inn Farm, I have ob- Cultivars of Ilex opaca. All the served that hollies have strong healing wild plants I have seen on Martha’s Vine- powers when damaged. For example, a yard have had very small berries. To ob- six- to ten-inch- (15- to 25-cm-) wide band tain garden-worthy subjects, I brought of bark that had been eaten by baby mice any Fl or FZ seedlings that had self-sowed from the trunk of a four- to five-inch- / 10- in my Delaware garden to the Barnard’s to 13-cm-) diameter Ilex opaca tree re- Inn Farm nursery for trial. The first selec- covered after I heaped damp oak leaves tion, made in 1960, was named ’Martha’s high around the base of the trunk, and Vineyard’. It has a formal growth habit, kept them damp. Tiny points of new bark making a tight cone, is as glossy as a emerged here and there, until the member of the species can be glossy, whole was renewed. (To discourage a and has very large, bright-red fruit. It is hardy and fast-growing, with a strong cen- tral leader. Good reports of the clone’s hardiness have reached me from farther north and farther inland. ’Barnard Luce’ is named for a descendant of an early settler of Martha’s Vineyard, Henry Luce, and the last one of the name to live (about a ccntury ago) at Barnard’s Inn Farm. Like ’Martha’s Vineyard’, ’Barnard Luce’ is a hardy, glossy "opaca," in this case from Maryland. It is more open and informal in habit than ’Martha’s Vineyard’ and shows off its bright-red fruits on long pe- duncles, resulting in a highly visible dis- play. My several trees come from cut- tings taken from a tree I discovered on Maryland’s Eastern Shore, near Barber. It was a female, especially selected for its high gloss. Ilex opaca ’Nelson West’ is a narrow-leaf male selection whose cuttings were taken from a tree in shady woods near New Lisbon, New Jersey. It is registered, and, though found in 1961, the the Fruit and Leaves Ilex Ai- Close-up of of opaca rooted cuttings have only grown to twelve- ton, a Species Native to the East Coast of the United States. Photograph (taken in 1899 by Alfred or fifteen-foot (3.5- or 4.5-m) trees. This RehderJ from the Archives of the Arnold Arboretum. wild plant is lacy, dainty, and graceful in appearance. Narrow-leaf forms with airy tolerance to coastal conditions. A low habit are seldom seen in Ilex opaca. meadow lies behind the beach, and there A new selection, ’Villanova’, regis- the old, gnarled trunks of the hollies rise tered in 1984, has yellow berries. This vertically-branchless for about eight feet was a lucky find nurtured from a tiny vol- (2.5 m)-then, making a right-angled unteer by my brother, Howard Butcher bend, horizontally, away from the wind III, at his home in Villanova, Penn- and water. At the tips of these branches sylvania. The shiny leaf is exceptionally one can find a few holly leaves to prove broad, almost round. The berry is distin- that they are alive and growing. The guished by its rich, deep-yellow color and grove’s origin is obscure, but it appears its spherical shape. The plant is being to be spontaneous. Elsewhere on the tested at Barnard’s Inn Farm. Vineyard, in a spot of woods sheltered I raise only a few of the many from high winds, there is a wild tree forty other named cultivars in existence. Of feet (12.5 m) in height. those few, I rate highest ’Jersey Knight’, a splendid male; ’Xanthocarpa’, a yellow- fruited tree from Longwood Gardens; and llex aquifolium ’Miss Helen’, a beautiful selection from McClean’s Nursery in Baltimore. I am Nowadays, sprays of the common holly raising about fifteen other cultivars-"old of Britain (Ilex aquifolium Linnaeus) timers" and newly registered plants- arrive on the East Coast in boxes ~, which I will evaluate once they have airmailed from the West Coast, where grown a while longer. they are raised in the splendid nurseries Ilex opaca, after experiencing the of Washington and Oregon. The leaves series of hurricanes that assaulted the may be variegated or all green; in either East Coast from the 1930s through the case the berries are red and 1950s, was rated second in salt and wind large-larger than those of Ilex opaca. tolerance; Pinus thunbergii, the Japa- Zone 6 is too cold for many cultivars of nese black pine, was, not surprisingly, Ilex aquifolium, but I planted the seeds rated first.