Vol. 10 No. 2 MORTON ARBORETUM JOY MORTON, Founder BULLETIN OF POPULAR INFORMATION LISLE, ILLINOIS May 20, 1935 Subscription $1 a year; lOc a copy. Copyrighted by Morton Arboretum LOCAL OFFICERS C. E. Godshalk, E. L. Kammerer, John van Gernert, Superintendent Botanist Propagator "HIGH-LIGHTS" OF THE SPRING BLOOMING SEASON Beginning with the Vernal Witchhazel, Hamamelis vernalis, whose tiny, fragrant orange yellow flowers were already scent­ ing the air by late February, a continuous procession of lavjsh blossom displays have passed in review. The Cornelian Cherries, Cornus mas, were the first sh.rubs in the Arboretum to produce a mass blossom effect. Their fat round buds, formed the fall before, always open at the first sign of warmth, disclosing dense clusters of diminutive golden yellow flowers. From mid-March through the first week in April, they were the most prominent feature of the landscape in the vicinity of Cedar Point. The Japanese Cornelian Cherry, Cornus officinalis, a close relative, bloomed slightly earlier. Its longer stemmed flowers and the presence of tufts of brown hairs in the axils of its leaves distinguish it from the former. During the last week in March, the early blooming Forsythia ovata began opening its solitary pale yellow bells. Introduced from northern Korea by Wilson in 1917, it is of particular value in localities where Forsythias are uncertain, due to its ability to withstand extreme cold. While we have never found it to be particularly floriferous here, it can almost always be depended upon to make a brave showing of yellow at least ten days or more in advance of its relatives. April first, found Forsythia viridissima koreana, a Korean form of the Greenstem Forsythia, fully budded. Unlike its sparse blooming parent, this showy variety puts forth its clustered ,bright yel- 5 low flowers in greatest profusion. It was effective until the middle of the month, at which time Forsythia saxatilis, a low, somewhat twiggy species obtained in 1928 from the Arnold Arboretum, had started to open its small lemon yellow flowers. The real climax of the Forsythia display was not reached, however, until the ."intermedia" varieties burst into bloom. They lasted until tlie first of May, presenting ,the most effec­ tive showing since 1932. Of the April blooming shrubs, none were more beautiful than the. Dahurian Rhododendron, Rhodod'endron dauricum. F_ully budded on the 19th, only two days of mild weather were necessary to bring out its fragile cup-shaped flowers of deep lilac-mauve. Never before has it produced them in such quan­ tity. This seems strange when we learn that its native habitat is in the colder regions of Manchuria and Korea. Our late frosts are responsible for this as they often nip its flower buds after they have been hastened into development by premature warmth. A variety of this species, R. dauricum mucronulatum, also blossomed this spring, but only scantily. Its flowers, while similar in size and shape to those of the type plant, differ in color, being a deep lilac-magenta. Both are true Rhododendrons of the deciduous-leaved type. While the Rhododendrons were at their best in Sargent's Glade, Prunus Armeniaca ansu, a variety of the common Asiatic Apricot, was the center of attraction in the Prunus col­ lection. Both specimen trees there were thickly studded with large, round pink buds which expanded on the 24th into de­ lightful masses of pink blooms. Unfavorable weather condi­ tions ended their effectiveness far too soon. Other equally attractive Prunus soon replaced them, how­ ever. The charming Higan or Spring Cherry, Prunus subhir­ tella, repeated its generous display of 1932, reaching its high­ est perfection of bloom on the 26th. Clear pink at first, the buds open lighter, hiding every branch and twig under an al­ most ethereal mantle of silvery pink. It is easy to understand why. this1tree is sometimes called the "Queen of Cherries." Prunus incisa, the Fuji Cherry, as though in competition with P. subhirtella, blossomed out into an even denser mass of pink. Its nodding short stemmed soft colored flowers, fully three-fourths of an inch across, remain attractive unusually long due to their persistent, vinous-red calyx lobes and yellow anthers. Many other Prunus furnished displays worthy of mention. 6 Among them were the ever popular Nanking Cherry, Prunus tomentosa, Prunus Korolkowii, a shapely, ascending branched species with pretty white flowers, Prunus cerasifera divaricata, the wild form of the Asiatic Cherry-Plum and Prunus salicina, the free blooming White Japanese Plum. At present our own native Plum, P.rqnus americana, and its numerous varieties are completing their part in the showing. Those to whom the double flowering Cherries appeal, had the opportunity of seeing several of these blooming during the early part of May. Prunus pseudocerasus fl. albo pleria was probably the most outstanding of them all. So double were its large white flowers that the tree appeared to be covered with myriads of long, drooping stemmed roses. Prunus serrulata pubescens Taizanfukum, another double Japanese Cherry, was blooming in a sheltered spot on the south lawn by May 10th. Although its large blush pink flowers are­ handsome enough individually, their beauty "en masse" is somewhat detracted by the bronze color of the unfolding leaves. Similar to the above Cherry is Prunus serrulata horinji, a dou­ ble or semi-double pale pink form with blossoms in loose clusters. Judging from the luxuriance with which the flowering Pears (Pyrus in variety) have blossomed, :it would appear that they were trying to out-do the Cherries and Plums. Instead of confining their flowers as in former years to a few of the upper­ most branches, every twig from fork to tip was heavy with bloom. The Ussurian Pear, Pyrus ussuriensis, has been mentioned in the Bulletin before, but inasmuch as it was the first species in the collection to flower, it ·may be well to review a few of its most desirable qualities. First of all, its shapely habit of growth is commendable, individual trees forming even and regularly branched specimens of neat outline. It has splendid foliage, too, the leathery leaves being deep green and lustrous. During its prolonged blooming season, April 25th to May 10 this year, its smooth-barked branches were crowded with dense, hemispherical clusters of pure white flowers. There are several varieties of the Ussurian Pear which are likewise worth cultivating; for example, P. ussuriensis Champali with denser clusters of fringed flowers, P. ussuriensis hondoensis with finer serrated leaves and longer stemmed blooms, and P. ussuriensis ovoidea with more spreading branches and ovoid to subglobose fruits. 7 Pyrus Calleryana, the Callery Pear, is another free flower­ ing oriental species wliich blossoms and leafs slightly later than P. ussuriensis. In the case of this tree, however, its varieties are even more beautiful than the parent, particularly the low, horizontally branched Pyrus Calleryana Faurei. After _seeing its graceful, tapering sprays of small, brilliant white blossoms with their prominent rose colored anthers, it will be agreed that this is one of the gems of the Pear family. Having a later season of bloom than its relatives, it prolongs the Pyrus display considerably. The other two varieties, while not so outstanding, are good, P. Calleryana graciliftora with its more open, irregular habit of growth and smaller flowers, and P. Calleryana tomentella with its densely tomentose branchlets. Pyrus serrulata, a Chinese introduction of 1917, also stood out prominently in the collection. The effect of its pure white flowers in combination with the pinkish-terra cotta tints of its unfolding leaves was most pleasing. Like P. ussuriensis it is a tree of symmetrical shape, perfectly fitted for specimen planting. Scarcely had the pears reached their prime when the multi-colored Japanese Quinces, Chaenomeles in variety, began to brighten the easterly base of Cedar Point. Although having become increasingly more floriferous in the past few years, they have never been more beautiful. In an open meadow in the same vicinity the pearly Juneberries or Shad­ blows, Amelanchier in variety, were concluding their finest exhibition. Attention is now focussed on the Flowering Crabapple collection (Malus in variety). Like a patchwork quilt worked in white, pink and rose, these dwarf apples spread out over the gentle slope rising above the eastern termination of Lake Road. While every species has contributed generously to the mass color effect, all honors for individual beauty belong to the hybrid form, Malus adstringens, whose soft rose pink flow­ ers of ·such a rare shade, have attracted the notice and admira­ tion of all who have seen it. It is a cross between the common Apple, M. pumila and the Siberian Crab, M. baccata. At the time of writing, the thorn trees (Crataegus in var.) throughout the Arboretum are deluged with snowy_ bloom. With the native pink crabapples, they form the most perfect combination imaginable. E. L. K. 8 .