July 8, 1891.] 



Garden and Forest. 



317 



Europe ; C. vulvaria likewise is found, but less generally 

 diffused. 



Portulaca oleracea, so common and troublesome in eastern 

 and European gardens and fields, has appeared in a few local- 

 ities, but, although doing well, has made no headway as a 

 troublesome weed. The altered aspect of its fleshy leaves, 

 which become much reduced in size, and almost terete, under 

 conditions of extreme drouth, so that the thick red stems re- 

 semble a group of stout, radially disposed worms, suggests a 

 marked adaptation to environments. 



The native C/aytonia perfoliata, although somewhat persis- 

 tent among the grass in moister ground in spring, hardly 

 maintains itself against regular cultivation, but its pretty 

 relative, the Calandrinia Menziesii, does not give up so readily, 

 and may be seen covering the ground in orchards and vine- 

 yards in the coast region, forming a beautiful carpet of purple 

 that attracts attention from afar. Its vegetative duration is 

 too short, and its root system too light, to render it troublesome, 

 but the multitude of its shining black seeds render it diffi- 

 cult of extirpation. 



University of California. E. W. Hllgard. 



New or Little-known Plants. 



Arbutus Arizonica. 



THE Arizona Arbutus has long been a puzzle to the 

 botanists, not many in number, who have seen it 

 growing. Dried specimens, as they appear in herbaria, 

 do not afford characters, except in their narrow leaves, by 

 which to distinguish them readily. Indeed, except in the 

 form of their leaves, several of the American species, in 

 all of which the flowers and fruit are very similar, are not 

 easy to separate in herbaria. The resemblance between 

 the three species which are found in the territory of the 

 United States is so great that Professor Gray at one time 

 considered the Texas tree a mere form of the Pacific coast 

 A. Menziesii, from which he did not distinguish our Arizona 

 plant at all ("Syn. Fl. N. A.," ii., i., 27). Afterward he 

 considered the Texas tree to be a variety of the Mexican 

 A. Xalapensis, which he called var. Texana, and the Arizona 

 tree another form, calling it var. Arizonica ("Syn. Fl. 

 N. A.," ed. 2, ii., i., Suppl., 396). The Texas tree, which I 

 have seen growing in several places in western Texas, in- 

 cluding Buckley's original station, does not, however, 

 appear distinct in any way from A. Xalapensis, as I under- 

 stand that species after having seen it growing on the 

 mountains near Monterey in Mexico, and in the series of 

 specimens preserved in the herbarium of the Royal Gar- 

 dens at Kew. As I know it, it is a low, wide-branching 

 tree, with a stout trunk separating near the ground into a 

 number of large, upright-growing stems. Near the ground 

 only the trunk is covered with thick dark brown or nearly 

 black deeply-furrowed bark, the surface of the ridges 

 separating gradually into thin scales. The remainder of 

 the trunk and the branches are covered with the thin, 

 smooth, bright red bark peculiar to all the plants of the 

 genus. The leaves are oval or ovate or rarely lanceolate- 

 oblong, two or three inches long, rather thick and coriace- 

 ous, dark green above and sometimes pale on the lower 

 surface. The ovary is pubescent. 



The Arizona tree differs from the other species of the 

 genus, as I know them, in the mature bark which covers 

 the trunk and the lower parts of the principal branches, and 

 which is as white as that of our White Oak and deeply fur- 

 rowed, the ridges being broken by cross-fissures into thick 

 square plates. The leaves are paler and much narrower 

 than those of the Texas tree, although much reliance can- 

 not be placed on the shape of the leaves of Arbutus, as 

 they vary strikingly on the same plant, and even on the 

 same branch. The character of the bark, which was the 

 same on all the trees seen by Dr. Engelmann and myself 

 on the Santa Rita Mountains, and the habit of the tree, 

 which is that of a small Oak, appear sufficient, however, to 

 distinguish this species which, if my views upon it are cor- 

 rect, will have to be called Arbutus Arizonica. It is 

 apparently confined to the mountain ranges of southern 

 Arizona ; at least, Mr. Pringle has found nothing like it in 



northern Mexico, although he has been on the lookout 

 there now for several years for all forms of Arbutus. 



Arbutus Arizonica (see Fig. 54) is a tree forty or fifty feet 

 in height, with a tall trunk eighteen inches to two feet in 

 diameter, covered with white bark, stout spreading 

 branches forming a rather compact round head, and 

 stout tortuous red branchlets. The leaves are pale, lanceo- 

 late, or rarely oblong, two to three inches long and a third 

 to nearly an inch broad, with entire or minutely denticu- 

 late margins, and are rounded or gradually contracted at the 

 base into slender-grooved petioles sometimes an inch long. 

 These, like the young shoots, are slightly puberulous when 

 they first appear. The inflorescence is two and a half to 

 three inches long, tomentose, with conspicuous scarious 

 bracts. The flowers are rather smaller than those of A. 

 Xalapensis, but otherwise not distinguishable from those of 

 that species, except in their pubescent ovary. The fruit 

 ripens in October, and is a quarter of an inch broad. 



Arbutus Arizonica is found on dry gravelly benches and 

 ridges between six thousand and eight thousand feet over 

 the level of the sea, growing with Quercus grisea, Q. Emoryi, 

 Q. chrysoiepis and Pinus ponderosa, just above the region 

 of Pinus Chihuahuana and below that occupied by Pinus 

 Arizonica. It appears to have been first noticed by the late 

 Dr. Thurber at the time of the Mexican Boundary Survey. 

 Much later it was collected by Rothrock, Lemmon, Sar- 

 gent and Engelmann, who first called attention to the 

 character of the bark, Pringle, and Mayr. It grows in a 

 region which is almost unsurpassed on this continent in 

 the variety and interest of the trees which compose its 

 forests — a region which will well repay more detailed study 

 at the hands of botanists than it has yet received. 



C. S. S. 



Cultural Department. 



Stray Notes from the Arnold Arboretum. — III. 



QOMETHING was said in the last issue of these notes of the 

 •^ horticultural value of the two arborescent Cornels of 

 eastern America, and now there is something to say in the 

 same connection of some of the shrubby species, among 

 which are to be found at least three or four excellent garden- 

 plants, and possibly more, but nothing is known yet of the be- 

 havior of the California species in cultivation. 



By far the most beautitul of our shrubby Cornels is Cornus 

 circinata. This is a plant of northern woods, in which it 

 grows in rich and in sandy soil or on rocky banks and hill-sides 

 from Nova Scotia to Dakota, and through the hilly and higher 

 parts of the northern states and along the mountains to Vir- 

 ginia. It is not a large plant, and produces rather rigid 

 erect stems rarely reaching the height of ten feet and 

 covered with smooth dotted bark, which is at first pale 

 green and later becomes light brown or purple. The leaves 

 are perhaps the most beautiful thing about this plant ; they 

 are large for the leaves of a Cornel— four or five inches long 

 and three inches or more broad — elliptical and long-pointed. 

 The color of the upper surface is yellow-green, while below 

 they are bluish white or steel colored and covered with short 

 soft hairs. The coloring of the leaves of few shrubs is more 

 striking and beautiful. The flowers appear rather early among 

 those of the Cornels and at the very beginning of June ; they 

 are produced in rather small, flat cymes, like the flowers of 

 most of our species, and are small and yellowish white. The 

 fruit is more beautiful than the flowers. It is spherical, as 

 large as a pea, bright blue, and very conspicuous for the size 

 of the clusters. It ripens early in the summer. This has 

 always been a favorite plant in the Arboretum, and has been 

 used in considerable numbers through the shrubberies and 

 along the drives. A few years ago it was only the botanists 

 who knew or cared anything about our Cornels and many 

 other native shrubs, but now landscape-gardeners and nur- 

 serymen are beginning to find out their value, and Cornels 

 and Viburnums appear in this vicinity not only in public gar- 

 dens and parks but in small villa gardens as well — a hopeful 

 thing, perhaps, as indicating that garden fashions in this coun- 

 try are working out of the old ruts and that the popular knowl- 

 edge and appreciation of plants is broadening. 



Ten years ago, in this neighborhood at least, the list of 

 shrubs one found in the majority of villa gardens, was a very 



