Eucalyptus

Foreword

The planting of trees of various species of Eucalyptus in California has been carried on since January, 1856, when Mr. C. L. Reimer successfully introduced 14 species. During all this time neither nurserymen nor the general public have had any work on this genus by which they could identify the various species. Everything depended on the seedsmen primarily and in a secondary way on the accuracy of the records of planters. From mistake in both these respects the greatest confusion and uncertainty has arisen. Of the large number of useful species introduced into California but three or four are certainly and generally known today. The botanical works covering this genus are inaccessible to the public on account of their great cost. There are only three copies of the Eucalyptographia and two of Bentham's books in this State, as far as I know. The importance of this genus as producers of kino, oils, timber and fuel, for ornament and the reclamation of waste places and for the probable sanitary effects of several of the species together with the rapidity of growth of nearly all and the remarkable adaptability to the major portion of California makes a means of identification a want that should be supplied. -fj Baron Ferdinand Von Mueller has, in the broad spirit of a true scientific man, given me the use of his great work on this genus, even to copying the plates.

Jl*

FORE WORD.

I have taken advantage of the courtesy of this distinguished man but the cost of using the plates would have defeated the main object I had in view, which is to make the knowledge of the Eucalyptus accessible to the largest possible number of enquirers.

I have also received very valuable aid from Mr. J. Ednie Brown, the prominent Australian Forester and botanist, and from Mr. Walter Gill, the present Forest Conservator of South Australia. The fine forest work in this colony under Messrs. Brown and Gill offers a wide field of knowledge to Eucalyptus planters.

Prof. A. J. McClatchie, of the Throop Polytechnic Institute of Pasadena, Cal., has given me specially valuable assistance, and I take pleasure in speaking of the important aid he has rendered in this work.

To many others I am much indebted for aid and information. Amongst them I may mention Hon. Thos. F. Bayard, now our ambassador to Great Britain, E. M. Shelton, Instructor in Argiculture, Queensland, Messrs. Scharf and Shorting, Pasadena, to Mr. Geo. S. Davis, publisher of the Bulletin of Pharmacy, Detroit, Mich., and to Prof. Tommasi Crudelei. Prof. J. H. Maiden, of Sydney, who is the authority on the chemistry of the Eucalyptus, has given me important help in various directions. Prof. B. E. Fernon, Chief of the Division of Forestry at Washington, has given me aid and comfort. The Rev. G. Montgomery, Bishop of Monterey and Los Angeles, assisted me in obtaining the original data of the Tre Fontane experiments for which I owe him much. Prof. S. M. Woodbridge, Ph. D., Hon. El wood Cooper, Mrs. Jennie C. Carr, together with many more have rendered me valuable assistance. Both our own Federal and all foreign officials appealed to

FORE WORD.

have gone to much trouble and pains to promote my work. Two Secretaries of State, one Secretary of the Interior and several scientific men of the Department of Agriculture have, by their kindly help, demonstrated the public spirit of our high officers. It is difficult for a reader of this book to appreciate what this help has been. Sometimes two or three words in a line will represent voluminous and prolonged correspondence. Sometimes the result of a year's investigation is to leave some statement out entirely.

This work is arranged in two divisions. The first contains a popular account of the species of Eucalyptus introduced into California as far as known. The location of illustrative specimens is in each case indicated so that enquirers may readily see for themselves what the tree looks like. The second division will contain the special examination of points of interest in this genus including methods of planting, timber strength, the oils and kinos, the medicinal value, the sanitary influence, vernacular names and lists of species suited to different conditions of soil and climate. This division will also contain a condensed botanic description of all the species of Eucalyptus described by Baron Von Mueller and taken from his great work. A few notes regarding varieties and points noted in California will be added to this. To facilitate the use of these botanic descriptions there will be a key and an illustration of the typical anthers, magnified sixty times, prepared by Prof. McClatchie, of the four classes established by Von Mueller. I believe that the key, plate and descriptions will enable any intelligent person to identify the leading species of Eucalyptus. To complete this part of the plan there will be a botanic glossary.

EUCALYPTUS.

GENERAL POINTS.

The Eucalyptus is a genus of hard wood, evergreen trees and shrubs. It belongs to the order Myrtaceae and to the tribe Leptospermeae. The name was suggested by the lid or cap-like covering over the immature flower. It is from the Greek and may be translated "well hidden." This genus was discovered and described first by I/Heritier, in 1788; who based it on the species "obliqua." The blue gum was discovered ten years later by Eabilliardiere, who described Eucalyptus cornuta at the same time. In 1806 Eabilliardiere described two other of the more valuable species, viz: Eucalyptus viminalis and Eucalyptus amygdalina. It is said that so large were the trees of the blue gum first seen by Labilliardiere in Tasmania, that he could ascertain that they were in flower only by his telescope. The flowers were brought down after prolonged firing at the upper branches with guns. Labilliardiere says in his own notes that he obtained the flowers and fruit by chopping down a tree.

The genus just escaped being called Aromandendrum. This name was given by Dr. Wm. Anderson, who described it independently when with Cook's second voyage io EUCAL YPTUS.

of discovery. Baron Von Mueller, coming into this field late, has described and named more species than any one person; in fact he is now the recognized authority on this genus. Anyone desiring to study the Eucalyptus should by all means procure Baron Ferdinand Von Mueller's Eucalyptographia, together with his other numerous works on the genus. Bentham's Flora Australiensis is reliable. The splendid work commenced by J. Ednie Brown on the Forest Flora of South Australia is in folio size and contains colored plates of each tree described. This work unfortunately was never finished. Prof. J. H. Maiden's "useful native plants of Australia" contains valuable information on the kinos, oils and timbers of the genus. Many valuable and interesting articles on the Eucalyptus are scattered about in scientific journals or in monographs practically inaccessible to us in California. Bentham's and Von Mueller's works are expensive. Most of the popular and many of the scientific monographs on these valuable trees and their products are out of print, and a considerable percentage are in French, and a few in Italian and Spanish. It seems useful, therefore, to bring some of this scattered information together in this work. To it I have added our Californian experiences. Indeed, it is especially to furnish a popular statement of facts for Californian use that I have undertaken this monograph on the Eucalyptus.

The first great acclimatizer and .Eucalyptus missionary was M. P. Ramel. This gentleman was so struck with the extraordinary qualities of this genus while at Melbourne, in 1854, that he started a crusade in its favor. Planchon calls Von Mueller the prophet and Ramel the apostle of the Eucalyptus. The first Eucalyptus tree known to have grown outdoors in Europe is said to have

EUCALYPTUS. u

been planted at Hyeres, in the South of France, in 1857. In 1875 this tree was 20 metres high, the trunk 1 metre from the soil was 2 metres 10 centimetres in circumference.

Certainly Ramel's enthusiasm for the Eucalyptus is well justified.

The highest monument in Europe, for instance, is 460 feet high, while the tallest Eucalyptus is 480 feet high.

Eucalyptus trees had, even in 1854, been planted by different gardeners in Europe, and at least one, by M. Hardy, in Algiers; but he did not know the tree until 1863, two years after the Hamma and Cordier plantations in that African province.

It was first called Eucalyptus glauca in Europe (Eucalyptus globulus) when grown from seed.

The Eucalyptus was introduced into this State in 1856. Hon. Ell wood Cooper, of Santa Barbara, has been probably the most active agent in bringing Californians to a knowledge of the Eucalyptus. Col. Warren of the California Farmer, Mrs. Jeanne C. Carr and General Stratton were also very active and enthusiastic as apostles of these trees on the Pacific Coast. It seems indeed regrettable that the work of Prof, and Mrs. Carr, at and about our University, in planting should be today so little available through the loss of the records.

The genus contains about 150 species, rather less than more, and the number is still not fully settled. This is on account of the doubt of the specific value of some now ranked as varieties and of others now ranked as species, and also on account of the incomplete study of the tropic flora of Australia, New Guinea, Timor and the Moluccas. If we consider the island of Tasmania as a part of Australia there are about five species of Eucalyptus found outside of that continent and all of these in the adjacent islands of New Guinea and Timor, and one only in the Moluccas. There is not a single species found in New Zealand. It seems indeed strange that the most adaptable of all forest trees to the semi-tropic world belt should be derived from so confined a genus. Besides this the most friendly to new conditions of all its species is one naturally limited to the damp gorges of Tasmania and Victoria. At least twenty important species of Eucalyptus have a wider Australian range than Eucalyptus globulus or the common blue gum. Still it is the blue gum that has been found thus far the best suited as a tree for other countries and wide ranges of soil - and moisture. In California when any one speaks of Eucalyptus trees in a general way the blue gum is meant. By this we may judge how completely our Eucalyptus plantations are dominated by this species.

The blue gum is a remarkable tree. It is about third as to height in the genus, being surpassed only by E. amygdalina and Eucalyptus di versicolor. The tallest blue gum measured was found in Tasmania and was 330 feet in height. Numbers have been measured over 250 feet, and a height of even 400 feet is claimed for it. In this matter of height measurement Von Mueller calls attention to the fact that extreme height in the Eucalyptus is due to long slim branches reaching skyward. In this respect it is quite different from the great stems of timber of our pines and Sequoias which have only very short vertical branches. Those of an ultra patriotic humor ma}' still claim that for tree height of solid stem and for cubic wood contents our Sequoias lead the world. In dry, open plains it is not likely that blue gums will grow to be very tall. In fact there are few in California over 150 feet high. If, however, some were planted in any of the burned and desolated redwood coast canyons of California where the conditions of moisture and exposure are similar to those in its native haunts we might reasonably expect to see blue gum trees eventually as tall as any in Australia. In its native haunts the blue gum is often, nay, generally, exposed to light frosts. Some very observant planters in the warmer parts of New South Wales state that the Eucalyptus globulus is never a long lived and really successful tree unless subjected to occasional nipping airs. Other authorities, however claim successful experiments in tropical highlands with this species, locations probably free from frost. But such reports are only made from tropical sections wdth a heavy rainfall. The tree has failed in Arizona and Texas. But, in those places, its failure is due, doubtless, to excessive frost on the one hand, and prolonged excessive heat on the other.

Mr. J. Ednie Brown and Mr. Walter Gill both found the blue gum unsuited to their interior plains (South Australia) generally similar in dryness and heat to our interior valleys. We have fully confirmed their experience except where the subsoil is moist.

In Arizona even this condition fails, apparently, to reconcile them to the prolonged heats of that section.

In Australia Eucalyptus leucoxylon, Eucalyptus corynocalyx and Eucalyptus polyanthema seem specially suited to sections too dry for the blue gum, and Eucalyptus rostrata for air too dry and hot and frosts too severe.

The blue gum is the fastest growing tree in the world. There are, indeed, trees that for a short time, or under special conditions, grow as fast as the blue gum. In fact in the damp Vitorian gorges the variety regnans of

Eucalyptus amygdalina is reported to grow faster than any wood-making plant. Nothing in our experience with regnans shows it to be a fast growing plant. So also, in experiments at and near Santa Monica we have found several species growing for a short time in that situation as fast as the blue gum. Of these experiments we may mention a Eucalyptus viminalis (Manna-gum) that, nineteen months from the seed, and fourteen months from the transplanting, without cultivation, on a side hill, grew fourteen feet six and three-fourths inches. 'A Eucalyptus corynocalyx (sugar gum) of the same age and in the same place grew only one-fourth of an inch less. I have seen an E. Gunnii for the first two or three years, grow faster than a blue gum by its side. But taking dry and wet canyon and plain the blue gum will exceed in growth any tree in the long run.

Some of the records are as follows :

GROWTH OF E. GLOBULUS.

Malaga. Spain, 6 yrs. ------- 65 feet

Nielgherry hills, India, 18 mos. from seed, 20to25 feet Eago Maggiore, Italy, 9 years, - - - - 60 feet

Nice, France, 5 years, 50 feet

Kinneloa, California, 8 years, ----- 71 feet

Experimental plantation of trees reported on by J. Ednie Brown, Conservator of Forests, S. Australia, showing comparative rate of growth of different trees similarly situated.

EUCALYPTUS.

Plantation C.

Height, Age and Girth of Trees.

Date of Planting iss,

Pinis insignis

" pinaster

" halepensis

Eucalyptus globulus

" longifolia

" oblique (Tasmanian Stringybark)

" diversicolor (karri)

" siderophloia (Ironbark)

Melia azedarach

Eucalyptus cornuta

" obliqua (South Australian Strtngybark) Pinus insignis

^Eucalyptus globulus

" longifolia

" siderophloia

" obliqua (South Australian Stringybark)

" corynocalyx

" cornuta

fCatalpa speciosa

|Fraxinus Americana

|| Walnut

Wattles (Acacia pycnantha)

" (small tree measurements)

Cupressus sempervirens

Age

Height years ft. in.

33 8

22 8

33 6

14 10

23 8

27 6

35 6

20 6

29 6

25 8

23 3

25 6

21 8

24 6

S

Girth 2 ft. from ground ft. in.

2 4

1 2

1 6 1 5 1 5 1 6 1 10

9 6

* Numbers averaging 40ft., and girthing from ift. 6in. to 2ft. 3m t Averaging

20ft. and ift. girth in best land. I Averaging 20ft. and 15m. in moist land,

leveraging 20ft. and isin. in girth, and in good bearing.

Measurements taken September 1st, 1886.

i6

EUCAL YPTUS.

Plantation E.

Height, Age and Girth of Trees.

Date of Planting

SS2

Name of Tree

* Eucalyptus viminalis

Eucalyptus globulus

Eucalyptus corynocalyx

Pinus maritima or pinaster fPinus insignis

J Pinus maritima

Age years

5 5

5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4

Height ft. in.

Girth at 2ft.

Height ft. in.

1 1

1 o

1 6

2 o

1 5

1 2

1 o

1 4

1 4

♦Numbers of these 20ft. in height. fA great number from 17ft. to 20ft. high.

Measurement taken August 31st, 1886. Height.

//eight, Age and Girth of Trees at White Park.

Date of Planting

Name of Tree

Plantation G

Pinus radiata

" maritima

" insignis

Eucalyptus viminalis leucoxylon

corynocalyx

gomphocephala

Plantation I

Quercus peduuculata

Catalpa speciosa

Populus fastigita

Ulmus suberosa

Eucalyptus leucoxylon

corynocalyn

■' viminalis

Pinus insignis

" maritima

Plantation J

Eucalyptus corynocalyx

viminalis

Girth

Age

Height

2ft.

Height years ft. in.

ft. in.

1 1

1 2

1 1

1 11

1 1

4to5

ECCALYPTUS.

n

Experimental plantation of trees at Santa Monica made by W. S. Lyon, Forester to the California State Board of Forestry.

Tract A.

Tract B.

Best.

Average.

Best

Average.

1. Eucalyptus polyanthema (Many-

Flowered Gum)

2. Eucalyptus globulus (Tasmanian

BUie Gum

3. Eucalyptus cornuta

4. Eucalyptus obliqua (Stringy Bark

or Messmate

5. Eucalyptus leucoxylon (Victorian

Iron Bark

6. Eucalyptus rostrata (Red Gum)....

7. Eucalyptus corynocalyx (Sugar

Gum)

8. Eucalyptus viminalis (Manna

Gum)

9. Eccalyptus Stuartiana ( A p p 1 e-

Scented Gum)

10. Acacia mollissima (Soft Leaf

Wattle)

11. Acacia pycnantha (Golden Wat-

tle)

12. Acacia melanoxylon (Blackwood)..

9.6

4.6

6 6 6.6 6 3 6

5-6 46

5-6 5-6 4 6 5 3

5 6 5-6

5-6

3 6 j Growth

in B small but thrifty.

None planted in B

4 Sent out last year

as the "Tooart Gum," remarkably thrifty in both plantations.

Moribund in 1!.

Lacks good color in A.

Richer, better

color in the iron soil.

..Not planted in A.

4.6

Not planted in B.

4 6 "Off" color in B.

Not planted in B.

Not planted in B.

Strongly

vigorous in both.

Sickly in A. Dead in B.

Analysis of Soil in Tracts.

Tract B.

Insoluble matter

Soluble silica

Potash (K..O)

Soda (N.,6)

Lime (CaO)

Magnesia (MgO)

Br. ox. manganese (Mr 2 4 Peroxide ot iron (Fe 2 3 )...

Alumina (A1 2 3 )

Phosphoric acid (P 2 0-,)

Sulphuric acid (SO ;i )

Carbonic acid (CO J

Water and organic matter...

Totals

Report of Byron O. Clark, Eucalyptus sideroxydon, (Eucalyptus leucoxylon) on the side of a zanja at Anahiem. Cut when 4^2 years old. Height 71 feet.

In Dr. Aber's plantations on the Rio de La Plata, Argentine the Karri, Eucalyptus diversicolor, grew fastest and Eucalyptus corymbosa ranked with blue gum.

At from ten to twelve years of age the blue gum in California ceases to maintain its phenomenal fast growth. The other species cease their fast growth, as a general rule, some years sooner. In this matter some ratio seems to exi«t between the duration of rapid growth and the eventual height of the tree.

The blue gum is like all the valuable species of Eucalyptus in not being able to stand prolonged or very heavy frost. What it will stand depends something on the humidity, the condition of the tree as to sap flow and the age of the tree. Old trees have withstood a temperature of 15 F. without material injury. Young trees will, however, stand no such temperature. A minimum temperature of 24 may be deemed safe. Von Mueller has noted the blue gum shoots on giant trees along the Dandenong range in Victoria, frost burned, and has also noted these trees covered with snow for long periods without injury. In California, one species of our indigenous Rhus of the disagreeable smelling leaf, what we call the evergreen sumac, is often frost burned in its native haunts. So in the blue gum and the sumac we find imperfect adaptation to their present native conditions, due perhaps to a changing climate.

This year we have had, in Southern California, nights colder than usual, that is, temperatures that occur once or twice in a decade. After these cold nights I visited two sandy washes along the foot hills, in one of which were 2

EUCALYPTUS. ig

year old small sugar gums (Eucalyptus corynocalyx) out one year, and in the other some yearling blue gums and many older, but stunted trees. In both washes the native sumac was frosted, and in nearly every case the whole foliage killed. The sugar gums were not all touched, but nearly all had the outer top leaves frost burned. Hardly any of the young blue gums were touched and these only very lightly. However, the young blue gums were among the older trees and doubtlessly received some protection.

Our common Rhus is comparatively rare along the coast further south, and another ornamental and very attractive Rhus, well worthy of gardeners' attention, takes its place. This latter, rare here, has not been frosted at all this year. This seems rather a strange thing, a southern type to be so resistant.

I am quite convinced that we could obtain a more reliable frost resistance in the blue gum by a careful gathering of seeds from trees thriving in the coldest places to which this species is indigenous. Although the native habitat of the blue gum is restricted, it still is subject to a consider- . able climatic range. Both in Victoria and Tasmania it climbs well into the mountain valleys, and it seems only reasonable that seed from some of the more exposed trees would resist more cold than those on the warm mesas. The seeds of all other plants are eventually impressed by the climates in which they are produced. This fact is availed of by agriculturists in vegetables, grains, etc. We know also that certain tree seeds all of the same species produce plants of different capacities in resisting cold on one side and heat and drought on the other. Take, for instance, the Douglass spruce indigenous from British Columbia to the Mexican line. Seeds of this spruce show great variations in the resistance of the trees they produce to unfavorable climatic conditions, and these variations correspond with the climatic conditions where the seed produced grew.

It seems only resonable to presume that this quality would extend also to the seeds of the blue gum. Our California plantations of blue gum are now practically all made from locally gathered seeds.

Doubtless, too, the prevalence of conditions, such as prolonged drought, whereby the tree remains dormant during the periods of exposure, would prove favorable to resistance of frost. The vegetable world, in this respect, is the opposite of the animal. There are indeed hibernating animals that remain dormant during the winter, living on themselves, but no animal can resist extreme cold so well with diminished as with active circulation. In the vegetable world the opposite condition prevails.

Animals suffer most from cold when exposed to wind. With plants it is exactly the reverse. At least such is the fact in the semi-tropics. A breeze on a cold night is considered a protection against frost. It is a wise precaution to discourage active sap circulation in delicate plants as periods of possible frosts approach. In irrigated sections this may be done by withholding water in the fall.

As the young Eucalyptus is more susceptible than the old to frost so we find numerous sections where this tree does well if the young are protected with straw, gunnysacks or any light covering; indeed just as young orange and lemon trees are in some of our interior plateaus. In these sections the citrus fruits are a success, but every now and again a great deal of snow falls in the neighboring mountains and the night air descending to the valleys is colder than usual. When to this condition we have added a dry still atmosphere the rapid radiation causes frosts severe enough to seriously injure and even kill young citrus trees. The shortness of the young trees is one element of their danger. The nearer the ground the greater the danger. One writer says that the climatic range of the orange tree is that of the blue gum and where one will grow so will the other. In contradiction to this, reports to me from Arizona mention citrus trees as successful and Eucalyptus a failure. In this case however it is said to be the prolonged dry heat that unfavorably affects the Eucalyptus (Eucalyptus globulus.) On the other hand the blue gum thrives remarkably in the damp cool climate of the California coast where the orange is a sad failure. About the Southern confines of Los Angeles city where the blue gum is in superb health and has a great development the orange tree also thrives but gives an inferior fruit with excess of acidity.

I think that the orange and blue gum will resist about the same degree of frost.

It should not be forgotten that water is an equalizer of temperature and helps frost resistance. Therefore if a frost threatens, a full flooding irrigation will diminish the danger.

In a Washington, D. C, nursery there is a Eucalyptus, species unknown, that for a number of years has been frozen every winter, but which sprouts anew each spring. In Paris the blue gum is sometimes used for ornament in the parks. The way this is done is to plant the seed in the open, transplant it to hot-house for winter, and set out the second summer, leaving it to its fate in the succeeding winter.

In Australia the numerous species of Eucalyptus have an extraordinary reported capacity of varying according to the soil and climate which they occupy. Some species have persistent bark in one geological formation and shed their bark in another. Some have green leaves, horizontal and broad near the coast and sickle shaped gray ones hanging vertical in the interior. The same species often vary, even in the color of their flowers. A number vary in the essential oils and odor of their foliage, and all are affected in the character and qualit} r of their timber by situation and climate. The forest trees indigenous to California have also often a strong tendency to vary, and again, like some Australian species, many of our trees are indigenous to very narrow limits. The Brewer, or beautiful weeping spruce, the Foxtail Balfour pine, the Torrey pine, the L,awson and Monterey Cypress, are amongst those so confined. One of our pines, the Monterey, P. iusignis, the fastest growing pine in the world, and more largely planted in Australia than any foreign tree, has a very restricted natural range about Monterey. We have in this pine some counterpart to the blue gums.

First — That it renders soil, air and water aseptic.

Second — That it is the most adaptable of our coniferous trees.

Third— That it is of so confined a natural habitat.

Fotirth — That other trees about it of very wide range like the Douglas spruce do not succeed in our plantations anything like so well.

So the blue gum of naturally restricted range succeeds better in plantations than very widely distributed Eucalyptus like, for instance, Eucalyptus rostrata, found in every division of Australia proper and absent only in Tasmania

The Monterey pine is a better tree than the blue gum.

for cold places, and on the blue gums' limit of temperature it is better for all sandy places and especially better for beaches exposed to sea winds. The Monterey pine, however, is not a valuable timber tree nor a good fuel one. Its uses are to hide scars, cover waste places, stop sand drift and look as handsome as a young pine can. It stands cutting and breaking better than any pine with which I am familiar. I know of one case where it sprouted from a blown over tree and grew well. The main tree was not cut off until the sprout had started.

Mr. L. Stengel, an experienced and careful nurseryman, is of opinion that Eucalyptus has a strong tendency to hybridize. There is just now a demand for Eucalyptus robusta (swamp mahogany). In preparing for this Mr. Stengel gathered robusta seed from four handsome specimens on Downey avenue, East Los Angeles. Recently while visiting his nursery Mr. Stengel showed me the results of his seed planting. The vast majority were true to the parent tree, but many in his large planting varied very widely from Eucalyptus robusta. One specimen was identical with globulus, several were like amygdalina varregnans; in fact about fifteen distinct species apparently came from these robusta seed. If hybridization be accepted as the cause of these nursery results, we may account for some of the truly extraordinary surprises Australian Eucalyptus seeds have given us. I have personally known seed from the collection of Baron von Mueller, and forwarded most kindly by him, come up in form quite foreign to the tree as described by him. I believe that every Californian experimenter in Eucalyptus has had a similar experience with Eucalyptus seeds.

Mr. Scharf, of Pasadena, who has taken a great interest

24 EUCALYPTI'S.

in introducing new species of Eucalyptus, has a number of sketches in color of the flowers of the ornamental Eucalyptus ficifolia, introduced for its brilliant red flowers. These sketches were largely of flowers from trees growing from seed gathered by himself from Eucalyptus ficifolia in his own nursery. The difference in the colors is radical, from pale orange yellow to deep red. The foliage in these ficifolias also varies greatly.

I am, however, not ready to accept these results as due to hybridization. Natural variation under new conditions and careless seed handling must be considered in the solution. Stengel's robusta is not the true robusta but a variety.

The blue gum is the best all round tree within its climatic range. It makes fire wood and timber fast; growing rapidly into an effective wind-break, contains a large amount of essential oil in its foliage ; its leaves are amongst the most efficient agents in cleaning out the incrustation of boilers. It is available for the medicinal preparation of Eucalyptol and is altogether the best tree for any considerable range of condition in semi-tropic climates as far as now known. The introduction of this tree has done more to change radically the appearance of wide ranges of country in California than any other one thing. In the reclamation of many arid plains of the central and southern parts of California the blue gum has worked almost like magic. It modifies the winds, breaks the lines of view all so quickly that one can scarcely realize that a valley of clustered woods and lines of trees was but a year or two before a brown parched expanse of shadeless summer dust. I do not think that the power of the blue gum in modifying the appearance of a country can be appreciated by any one who has not seen some stretch of country before and after its introduction.