484 



HOETICULTUEE 



October 3, 1914 



ARNOLD ARBORETUM BULLETIN No. 62, 



The flowers of woody plants are not 

 common in this climate at the end of 

 September, but visitors to the Arbore- 

 tum will still find a few interesting 

 plants in bloom. The most conspicu- 

 ous, perhaps, is the Manchurian and 

 north China Aralia cMnensis. It is 

 a near relative of the so-called Hercu- 

 les' Club (Aralia spitiosa) of our 

 southern woods and, like the American 

 plant, it has stems covered with 

 prickles, large, compound, dark green 

 leaves, and immense clusters of small 

 white flowers which are followed by 

 small shining black fruits. The 

 American plant is not quite as hardy 

 as its Asiatic relative, but it is now 

 well established here. The plants are 

 just past flowering. 



The Japanese Hydrangea paniculate 

 and its monstrous form, on which all 

 the flowers are sterile (var. grand i- 

 flora) are in bloom. The latter is 

 one of the most generally planted 

 shrubs in the United States, although 

 it is a much less interesting and less 

 beautiful plant than the still com- 

 paratively little known normal form. 

 In the Shrub Collection, too, the hand- 

 some Elsholtzia Stauiitonii Is in full 

 flower and now at its best. This mem- 

 ber of tbe Mint Family, and a native of 

 northeastern Asia, has long erect spikes 

 ■of rosy pink flowers and light green 

 foliage. One of the comparatively re- 

 cent introductions of the Arboretum, 

 it is only beginning to appear in 

 American and European gardens. Near 

 it Vitex incisu from northern China is 

 in flower. Although this plant is a 

 native of a cold region the stems are 

 •often killed back to the ground here 

 in severe winters, but as new stems 

 grow several feet tall during the sea- 

 son, and as the flowers are produced 

 on the new growth, this killing back 

 improves rather than injures the flow- 

 ering of tbis shrub which at this time 

 of the year is attractive with its 

 finely divided leaves and slender erect 

 clusters of small rose-colored flowers. 

 The flowers of the true Heathers (Cat- 

 lima) have already passed but flow- 

 ers may still be seen on the Cornish 

 Heath, Erica vagans. and the Trum- 

 pet Creepers from the central and 

 southern states are still producing 

 iiowers. 



Small plants of Gordonin Altaniaha 

 are now in bloom and during several 

 ■weeks will continue to open their 

 white cup-shaped flowers which re- 

 semble those of a single-flowered Cam- 

 ellia. This tree is a native of south- 

 ern Georgia where it was discovered 

 late in the eighteenth century. Al- 

 though often hunted for, it has not 

 been seen growing wild for more than 

 a hundred years, and has only been 

 preserved by the cultivated descend- 

 ants of the plants introduced by its 

 early discoverers. This Gordonia 

 florishes in the neighborhood of Phila- 

 delphia but it is not very hardy in 

 the Arboretum, and it is surprising 

 that it was uninjured by the severity 

 of last winter which destroyed so many 

 ■hardier plants. Indigofera amblpanth'a 

 which has been in flower for nearly 

 three months, still continues to pro- 

 duce its slender erect spikes of rose- 

 colored flowers. This is one of Wil- 

 son's discoveries in western China and 



one of the most beautiful of the small 

 hardy shrubs of recent introduction. 



The name Vlmus campeslris has been 

 selected by recent writers on Euro- 

 pean trees for the Elm of the hedge 

 rows of southern England, which was 

 largely planted a century ago in east- 

 ern Massachusetts chiefly, no doubt, 

 through the agency of a Major Pad- 

 dock who established a nursery of this 

 tree in Milton. The large English 

 Elms which once flourished on Boston 

 Common were of this species, and 

 large specimens can still be seen in 

 several of the Boston suburbs. The 

 origin of this Elm is unknown. It 

 does not produce seeds propagating it- 

 self by suckers, and is known to grow 

 spontaneously only in some of the 

 countries in southern England, and in 

 a few parks near Madrid, in which it 

 is now known to have been introduced 

 from England many years ago. It is 

 a noble tree, able to adapt itself to 

 various climatic conditions, and well 

 suited to those of New England; in- 

 deed no other exotic tree, with the ex- 

 ception of the European White Willow, 

 has been here so long or grown to such 

 a large size. Another English Elm, 

 Vlmus vcgeta. usually called the Hunt- 

 ington Elm, a supposed natural hybrid 

 between two European species, Ulmus 

 nitens and V. glabra, the so-called 

 Scotch Elm, grows to a larger size 

 than Vlmus campeslris and is perhaps 

 the fastest growing of all Elm trees. 

 An Elm of this kind in the deer park 

 of Magdalen College at Oxford, sup- 

 posed to have been planted at the time 

 of the Restoration, was blown down in 

 April, 1911: it was one hundred and 

 forty-two feet high, with a trunk cir- 

 cumference at four feet from the 

 ground of twenty-seven feet. This was 

 believed to be the largest tree in Great 

 Britain and perhaps in Europe. Vl- 

 mus vegeta is a tree with paler bark 

 than that of Vlmus campeslris, large 

 main branches spreading at narrow 

 angles, giving the tree a vase-shaped 

 form, rather pendulous branchlets and 

 larger leaves than those of Vlmus 

 campcstris. and usually only slightly 

 roughened on the upper surface. This 

 free is not rare in English parks and 

 has been largely planted in Cambridge- 

 shire where in the neighborhood of 

 Cambridge there are many fine speci- 

 mens. Brooklands Avenue in that city 

 planted with this tree in 1830, shows 

 its value for such planting, for in all 

 England there is perhaps not a better 

 example of an avenue of planted trees. 

 The Huntington Elm was certainlv in- 

 troduced into New England much later 

 than Vlmus campeslris, and probably 

 the oldest trees here are not more 

 than sixty or seventy years old. This 

 Elm is perfectly hardy here, it grows 

 with surprising rapidity, and if exotic 

 Elms are to be planted in the United 

 States it may well be more generally 

 used here than it has been. 



Persons interested in the plants best 

 suited for the parks and gardens of 

 eastern North America can find mui'h 

 to learn in the Arboretum from this 

 time until the end of the year, for 

 it is the autumn that conifers are seen 

 to the best advantage and that the 

 mature leaves of the few broad-leaved 

 evergreens which flourish in this cli- 

 mate best show the beauty and value 



of these plants for the late autumn 

 and winter garden. Perhaps nowhere 

 else are so many different plants with 

 brilliant autumn foliage and handsome 

 and abundant autumn fruits assem- 

 bled; and in no other garden can such 

 plants be so easily and conveniently 

 studied. Such plants give a character 

 and beauty to the autumn garden 

 which can be found only in eastern 

 North America, and perhaps in Japan 

 where the leaves of many of the na- 

 tive trees and shrubs. assume brilliant 

 colors before they fall. 



The autumn color of a few plants is 

 already brilliant. The earliest of the 

 American trees to change the color of 

 its leaves is the Red or Scarlet Maple, 

 Acer ruhrum. On specimens of this 

 tree growing in swamps the leaves are 

 now often bright scarlet, while on 

 trees growing on higher and drier 

 ground the leaves are still bright green 

 or only slightly tinged with red. The 

 so-called Water Willow, Decodon verti- 

 cillatus. often known as Nessea, is a 

 native of all the region from Maine 

 to Florida and Louisiana, and is a 

 shrub with arching stems growing 

 only in the wet, often submerged bor- 

 ders of streams and ponds where it 

 often spreads into broad thickets. By 

 the borders of the ponds in the Arbore- 

 tum the leaves of this plant are al- 

 ready bright scarlet, and for a few 

 weeks the plants will be conspicuous 

 among the green sedges and swamp 

 grasses with which they are associated. 

 The leaves of some of the forms of 

 the so-called Virginia Creeper of east- 

 ern North America are already bright 

 scarlet. The earliest to adopt its au- 

 tumn dress and now in brilliant color 

 is Parthrnocissus i-itacea. This plant 

 rarely has adhesive discs at the ends 

 of the tendrils, and therefore cannot 

 attach itself to the trunks of trees or 

 to brick and stone walls, like Parthen- 

 ocissus quinqucfolia which is often 

 sold in nurseries as Amprlopsis Engle- 

 man nil. 



A few of the fruits which ripen in 

 early autumn are already conspicuous. 

 There is perhaps no shrub more beau- 

 tiful in the autumn than one of the 

 American Cornels, Cornus rugosn, or 

 as it is sometimes called, C. circinatn. 

 It is a tall, broad, round-headed shrub 

 with greenish branches and round, 

 oval, dark green leaves; the flowers are 

 not more showy than those of the other 

 Cornels, but the clusters of light blue 

 fruits on red stalks make them objects 

 of much interest and beauty. The red 

 Osier Cornel, Cornus racemosa, often 

 called C. stolonifcra or C. candidissima 

 is also beautiful at this season, for the 

 leaves are beginning to turn dark red 

 and the plants are covered with abun- 

 dant clusters of white fruits on bright 

 red stalks. This plant has been large- 

 ly used in the Arboretum; it spreads 

 rapidly into large, dense clusters, and 

 with its good foliage, abundant flowers 

 and beautiful fruits, few shrubs are 

 more desirable for park and roadside 

 plantations. 



The fruit of some of the new Chin- 

 ese Cotoneasters is handsome and the 

 autumn coloring of their foliage is of- 

 ten splendid. Most of these plants are 

 perfectly hardy, and among them are 

 certainly some of the most valuable 

 garden shrubs of recent introduction. 



