fractions, according to species Five Poisonous Range Weeds- . and season. When possible, the same species was sampled at dif- When and Why They Are Dangerous ferent elevations on the same date. The individual parts M. COBURN WILLIAMS AND EUGENE H. CRONIN were dried for 24 hr at 60 C, Plant Physiologists, Crops Research Division, Agricul- ground to a 40-mesh powder, and tural Research Service, U.S.D.A., in cooperation with the Agricultural Experiment Station, Logan. stored in air-tight polyethylene containers. Highlight poisons has been reported by Larkspurs and falsehellebore Three larkspurs, halogefon, and Dye (1956)) Williams (1960)) were analyzed for total western falsehellebore were exam- Cook and Stoddart (1953)) and as previously described for tall ined for seasonal variation of their contained poisons. With the excep- Morton et al. (1959)) on haloge- larkspur (Williams and Cronin, tion of low larkspur, greatest con- ton; Beath (1919, 1925)) and 1963). Soluble and total oxalates centrations of fhe poisons were Williams and Cronin (1963)) on in halogeton were determined found in the leaves. concen- tration in tall larkspurs decreased larkspurs; and Keeler and Binns by the method of Dye (1956). with plant maturity. Cattle losses (1964)) on falsehellebore. Our The above have, for a mav be reduced if fall larkspurs are continuing research was con- number of seasons, been analyzed avoided during early vegetative qrowfh. The alkaloid content of tall ducted with five poisonous spe- for changes in the concentration larkspurs was increased by freaf- cies common in the Intermoun- of their contained poison follow- menf with 2,4,5-T and silvex. Only ing applications of experimental 2,4,5-T increased alkaloid content of tain West: duncecap larkspur, western falsehellebore. ( occidentale S. herbicides. Samples were taken Wats.; tall larkspur, D. barbeyi 1,2, and 3 weeks after treatment, Poisonous plants have always (Huth) Huth; low larkspur, D. and processed and analyzed as constituted an indigenous com- nekonii Greene; halogeton, Halo- described. ponent of the flora of the West- geton glomeratus (M. Bieb.) C. A. Results and Discussion ern range. Halogeton (Halogeton Mey.; and western falsehellebore glomeratus (M. Bieb.) C. A. Veratrum californicum Durand. Tall and Duncecap Larkspur.- Mey.) is the only one of our most With the exception of duncecap More cattle are killed in the troublesome poisonous weeds larkspur, the common names West by tall larkspurs than any which has been introduced. used are those approved by the other poisonous weed. Authen- The native larkspurs (Delphin- Terminology Committee of the ticated cattle losses attributed to ium spp.) , western falsehellebore Weed Society of America (Dar- tall larkspur on one grazing (Veratrum californicum Dur- row et al., 1962). Duncecap lark- allotment in Utah have ranged and), and halogeton have become spur is designated as the com- from 2 to 12% during the last 10 management problems by (1) mon name for DeZphinium occi- years. introducing domestic animals dentale in Standardized Plant Plants begin growth in late where these weeds are prevalent; Names (Kelsey and Dayton, spring as soon as snow has mel- and (2) range misuse, particular- 1942). Unfortunately, duncecap ted. As many as 20 to 30 shoots ly overgrazing, which permits larkspur is usually called tall may arise from a single crown. weeds to increase in density and larkspur in the West and is there- In the vegetative stage, tall lark- invade new areas at the expense fore frequently confused with spurs resemble the poisonous of desirable vegetation. Delphinium barbeyi. monkshood, Aconitum colum- Apart from recognizing these bianum Nutt. Tall larkspurs, species in the field, few under- Materials and Methods however, have hollow stems and stand the complex physiological Plants were collected by loca- prefer well-drained soils, while characteristics peculiar to each, tions, as follows: low larkspur, monkshood has a solid, pithy such as the poison or poisons it duncecap larkspur, and western stem and occurs on moist sites. contains; why only certain classes falsehellebore, Wasatch Moun- Flowers of the two genera are of livestock are poisoned; the tains east of Logan, Utah; tall easily distinguished because the distribution of the poison within larkspur, Wasatch Plateau east calyx on monkshood lacks the the plant; how the poison content of Manti, Utah; halogeton, west spur characteristic of larkspurs. varies during the plant’s life of Snowville, Utah. Plants were Tall larkspurs produce flowers cycle, and the effect of climate sampled weekly in the field from from July to September. The and herbicides on the concentra- soon after emergence until ter- flowering plants average 3 to 4 tion of the poison. mination of their active growth. ft in height but may reach 6 ft or Information on the character- Plants were divided into leaf, more. Tall larkspurs grow at an istics and properties of plant stem, flower, and leaf-seed- elevation of 6,000 to 11,000 ft,

274 POISONOUS RANGE WEEDS 275

Table 1. Percent fofal alkaloids in planf tissue of duncecap larkspur, wesiern falsehellebore. and low larkspur, 1965. Duncecap larkspur Western falsehellebore Low larkspur Date of 7000 ft 8000 ft 6000 ft 8000 ft 8000 ft Collection Apex Leaves Stems Apex Leaves Stems Leaves Stems Leaves Stems Leaves Stems Flowers May 28 ------0.3 0.5 June 3 ------0.3 0.2 June 10 4.1 3.7 2.6 - - - 0.2 0.2 June 17 2.5 2.4 1.5 - - - 0.2 0.1 - - - - - June 23 3.0 2.3 1.1 5.4 3.5 3.5 0.2 0.2 0.4 0.4 0.2 0.1 - June 29 2.6 2.1 1.0 4.6 4.5 3.4 0.2 0.2 0.5 0.3 0.2 0.2 - July 8 3.3 2.1 0.7 3.1 2.7 1.5 0.2 0.2 0.2 0.2 0.2 0.4 0.5 July 15 3.3 1.8 0.6 3.3 3.2 1.1 0.3 0.3 0.2 0.2 0.3 0.3 0.6 July 21 2.8 1.6 0.7 3.5 2.8 1.1 0.2 0.1 0.2 0.2 0.2 0.2 0.4 July 28 2.3 1.3 0.8 3.3 2.2 1.1 0.2 0.2 0.2 0.2 - 0.3** - August 5 2.0 0.9 0.8 2.6 1.6 1.1 0.3 0.2 0.3 0.2 - 0.2** - August 12 2.1 1.2 0.6 2.0 1.6 0.6 0.2 0.1 0.2 0.1 - 0.2** - August 19 0.9 0.6 0.4 2.3 1.4 0.5 0.2 0.2 0.3 0.2 - August 26 0.8 0.6 0.4 2.3 1.2 0.7 0.2” 0.2* 0.2 0.1 - September 2 0.8 0.6 0.3 2.8 1.0 0.5 - - 0.2* 0.2” - September 9 0.6 0.5 0.3 1.9 0.8 0.7 September 20 - - - 1.0” 0.3” 0.4” * Plants dead ** Whole plant samples only either on open meadows or inter- Tall larkspurs are most poison- In years when cattle losses spersed among aspen and fir. ous during early growth, espe- from tall larkspurs are unusually Tall larkspur may be distin- cially during the first few weeks heavy, ranchers frequently as- guished from duncecap larkspur following emergence (Table 1). sume that the plants are more by the tawny pubsecence of its Alkaloid content decreases rapid- toxic than usual. This assump- and by its tendency ly until flowering, during which tion is true if losses occur follow- to produce bi-colored (light blue alkaloid levels drop more slowly. ing a winter of above normal and dark blue) petals. Tall lark- After the plants have reached snowfall or if the spring is un- spur occurs in , New full flower, alkaloids rapidly de- usually cold. The toxicity of lark- Mexico, , and Southern cline. At 7,000 ft elevation, the spur is dependent upon two con- Wyoming and Utah (south of apex consisted of leaves June 10 ditions: date of emergence, large- Provo). Duncecap larkspur grows to July 1; buds July 1 to 15; ly determined by winter snow- generally north of tall larkspur flowers July 15 to 30; and seed fall, and temperature following in Northern Utah, Idaho, Nevada, pods and seeds thereafter. Equiv- emergence. Toxicity corresponds Northern Wyoming, Montana, alent growth stages in plants col- very closely to stage of growth. Oregon, and Washington. lected at 8,000 ft occurred 2 to 3 The later the start of growth, the The toxic substances in lark- weeks later. more toxic plants will be-at any spurs are alkaloids. These com- The majority of the alkaloids particular date during the grow- pounds are complex organic are found in the green leaf. ing season. Cold weather follow- molecules which contain, in ad- Young leaves, particularly the ing emergence can further retard dition to carbon, hydrogen and apical bud, are rich in alkaloids. development. oxygen, a small amount of nitro- Stems are high in alkaloids only Duncecap larkspur (Table 1) gen. Alkaloids are widely dis- when very young and succulent; was collected at 7,000 and 8,000 tributed throughout the plant and as they become more woody, ft elevations. Plants at 7,000 ft kingdom. Many that occur in the concentration of the poison were 18 to 20 inches high before small amounts in food are harm- drops very rapidly. Before the snow had melted at 8,000 ft. less but other alkaloids, such as bud stage of development, the Consequently, the stage of de- morphine, atropine, and strych- dry weight of the plant is about velopment of plants at 8,000 ft nine, are highly poisonous, evenly distributed between the was 3 weeks behind those at the though all three have great me- leaves and stems. After flower- lower elevation. Until late in the dicinal value under controlled ing the older leaves begin to die, season, higher elevation plants use. Familiar examples of alka- thereby reducing the percent dry contained a larger concentration loids are caffeine in coffee and weight of the leaves in a whole of alkaloids than lower ones at nicotine in tobacco. plant sample. each date of collection. Duncecap 276 WILLIAMS AND CRONIN

larkspur, collected on September land heavily infested with lark- are more toxic than others; 9, 1965, at a site above 8,000 ft, spur. therefore, the toxicity of indi- from which snow did not melt Most losses from tall larkspurs vidual species will depend upon until August, contained 1.3% and occur within 2 weeks after cattle type and concentration of alka- 0.7% alkaloids in the leaves and reach infested areas. Plants usu- loid. The same alkaloid may oc- stems, respectively. These plants ally have not reached full-bloom cur in several species of larkspur; were flowering, and at a stage of and are therefore highly poison- others are unique only to one growth comparable to larkspur ous. Few losses occur after the species. Beath (1925) extracted on July 28 on the 7,000 ft site. full-bloom stage of growth is crude alkaloids from five species The similarity in alkaloid con- over. Alkaloid level in duncecap of larkspur, including those dis- tent is striking and emphasizes larkspur at 7,000 ft declined to cussed here, and evaluated their the close correlation between less than half by full-flower in relative toxicity via intravenous stage of growth and toxicity in mid-July. By September the injections in rabbits. Alkaloids tall larkspurs. plants were, at most, only about from low larkspur were most Because of above normal one-seventh as toxic as on June toxic, while alkaloids from tall snowfall, tall larkspur at Manti 10. Since stems account for an larkspur were only slightly less did not emerge on many sites increasing percentage of the dry poisonous. Alkaloids from tall until August. The alkaloid con- weight later in the season, the and low larkspurs were three tent of both leaves and stems was actual toxicity was undoubtedly and four times more poisonous, much higher than at comparable much less. respectively, than alkaloids from dates in 1963, when the growing Tall larkspurs are not unpalat- duncecap larkspur. The alkaloids season began earlier (Table 2). able to cattle, and releasing a of duncecap larkspur were the We have no information re- hungry herd onto an infested least poisonous of the five spe- garding larkspur toxicity as in- area merely invites disaster. cies examined. On the range, fluenced by moist or dry grow- Low larkspur .-Low larkspur however, duncecap larkspur is ing-seasons. One would suspect is widely distributed from South actually more poisonous than that alkaloid metabolism in deep- Dakota westward to Colorado, low larkspur, since it contains up rooted perennial tall larkspurs Wyoming, Utah, and Idaho, to 10 times more alkaloids per would seldom be affected by where it thrives on foothills, gram of plant tissue. Tall lark- moisture limitations at higher plains, and open mountain mead- spur not only contains the more elevations. Abnormally heavy ows. The plants emerge in early poisonous types of alkaloids, but cattle losses during a season spring after snow melt, flower in produces them in concentrations when tall larkspur begins early June and July, then dry up and equal to any other tall larkspur. growth cannot be traced to ex- disappear. Each plant consists of The heavy cattle losses caused by cessive toxicity in the plants; one or two stems, two to six this species are, therefore, not rather, conditions favoring in- leaves, and, when in full flower, suprising. Clawson (1933) re- creased consumption of the it reaches a height of 1 to 2 ft. ported that the lethal dose of plants must be responsible-poor Low larkspur alkaloid levels young tall larkspur may be as range condition, lack of forage, do not vary greatly during its low as 0.7% of an animal’s or releasing hungry animals onto short growing season except that weight, or roughly 3.5 lb for a they tend to be higher during 500-lb animal. flowering. The small leaves dry A few seconds of additional Table 2. Seasonal distribution of alkaloids (percent) in fall larkspur. rapidly after flowering; there- grazing on any larkspur species fore, only whole plant samples may mean the difference be- Date of 1965 1963 ’ were collected late in the season tween mild symptoms and fatal collection* Lvs. Stems Lvs. Stems ______(Table 1). The alkaloid content poisoning. It should not, for prac- July 10 - - 2.8 2.8 is only 10 to 20% of that found tical purposes, be inferred that July 18 - - 2.5 1.4 in the tall larkspurs; therefore, alkaloid toxicity varies to the ex- July 23 3.4 2.1 1.9 0.9 cattle losses tend to be less tent that various species can be July 30 2.8 1.6 1.8 0.5 Aug. 4 2.8 1.3 1.7 0.4 severe. At the site where these categorized as “more toxic” or Aug. 11 1.9 1.4 1.2 0.4 collections were made, the plants “less toxic”. All species are dan- Aug. 17 1.5 0.7 1.1 0.3 had largely matured and disap- gerous. But cattle losses recorded Aug. 27 1.3 0.4 1.0 0.2 peared before cattle were re- over the years suggest that tall Sept. 3 1.9 0.8 0.5 0.2 leased on the area. larkspur must rank first as a Sept. 7 0.9 0.7 0.4 0.1 Alkaloid concentration does killer in the Rocky Mountain * Dates are for 1965. Dates for 1963 not, alone, determine larkspur region. were either the same or varied by toxicity. Each species contains Western FaZseheZZebore.- only 1 or 2 days. several alkaloids, some of which Western falsehellebore is a tall, POISONOUS RANGE WEEDS 277

Halogeton. -H&g&on is an annual of the goosefoot family which, since its introduction 30 years ago, has invaded 12 million acres of Western rangeland. The plant contains unusually heavy concentrations of soluble oxa- late which are bound primarily as sodium salts. Oxalates are readily absorbed into the cir- culatory system of the affected animal. There the two sodium ions are replaced by one calcium withdrawn from the serum cal- cium. Excessive depression of the serum calcium level is inevit- ably fatal. Calcium oxalates are then precipitated primarily in the liver and kidneys where they interfere with normal function of these organs. FIG. 1. TVestern fal;ehellehore infestation Soluble oxalates are highest in Forest, Idaho. the leaves and lowest in stems of halogeton (Table 3). Seed con- robust member of the lily family bore contain monobasic and tains about 2% soluble oxalates which grows above 5,500 ft ele- steroidal-type alkaloids, but are (Williams, 1960). Though halo- vation. In flower the plant stands not known to contain the same geton produces primarily soluble 6 to 8 ft tall. Individual leaves specific alkaloids. Falsehellebore oxalates, some insoluble oxalates, measure up to 9 x 12 inches. is seldom grazed by cattle; there- primarily salts of calcium, are Plants emerge as soon as snow fore losses are almost entirely present. Insoluble oxalates are melts, flower in July and August, confined to sheep. not absorbed; therefore they are and set seed in September. Seed Alkaloid content in falsehelle- nontoxic. Soluble oxalates pre- production is erratic, however, bore is highest when plants dominate in the leaves while in- and in some years plants may emerge. The level drops quickly soluble oxalates occur in higher dry up and become dormant to about 0.27% of the dry weight conc@rations in the stems. while in full flower. Plants of the plant. The alkaloid con- The oxalate content of the rooted in moist seeps become centration varies slightly above halogeton leaf tends to be rela- dormant as rapidly as those on or below this figure throughout tively high during midsummer, dry sites. In 1964, seed produc- the season until the plant dies. then peak in September (Wil- tion was abundant. In 1965, few The stems contain slightly less liams, 1960). The data in Table 3, flowers and no seed were pro- alkaloid. Flowers have little or duced on the same area even no alkaloid content. Table 3. Seasonal disfribtiion of though moisture and growing The altitude difference in soluble and insoluble oxalafes conditions were more favorable Table 1 represents 2,000 ft. Late (percent) in stem and leaf-seed- sepal fractions of halcgeton. than during the preceding year. emerging plants were higher in Several alkaloids are found in alkaloids than older plants at Date of Lf.-seed-sepal stems western falsehellebore (Keeler lower elevations only for a pe- collection Sol. Insol. Sol. Insol. and Binns, 1964). One or more riod of 2 weeks. After July 8, no June24- 25.0 3.2 3.4 7.6 of these acts as a teratogenic significant differences in alka- July 9 24.3 4.5 2.9 6.0 agent which causes severe mal- loid levels were apparent. July 22 22.6 4.9 4.1 6.1 Aug. 6 formations in lambs. if the ewe The data indicates that false- 22.3 5.3 2.3 2.6 Aug. 19 22.9 1.7 3.8 4.5 eats the plant during the very he&bore is capable of producing Sept. 3 19.1 5.4 1.1 3.7 early stages of gestation (Binns its toxic effects with almost uni- Sept. 17 16.4 3.5 1.6 5.5 et al., 1963). This problem has form intensity throughout the Oct. 1 16.3 3.4 1.6 4.2 been particularly severe in Idaho growing season. Dead but unde- Oct. 15 24.5 3.9 4.0 3.9 where ewes are bred on the composed leaves are frequently Oct. 26 24.4 9.0 2.1 4.8 range for early lamb production. as high in alkaloids as the green NOV. 12 25.5 3.1 1.9 2.6 Both larkspurs and falsehelle- leaf. Nov. 23 19.1 3.0 1.9 3.6 278 WILLIAMS AND CRONIN however, represent a leaf-seed- near Powell, Wyoming, Novem- now being tested affect alkaloid sepal fraction, so that the lower ber 26, 1965, contained the same content in falsehellebore. The oxalate content noted from Sep- concentration of soluble oxalates concentrations of oxalates in tember to early October repre- found in plants from Snowville, halogeton and alkaloids in low sents inclusion of flowers, seeds, Utah. In Wyoming Bohmont et larkspur have been neither and - all of which are al. (1955) found that oxalate con- raised nor lowered by any her- lower in oxalates and thereby tent in halogeton ranged from bicides thus far evaluated, in- dilute the overall oxalate concen- 14 to 21%; this is no different cluding 2,4,5-T and silvex. Be- tration. By mid-October seeds from whole plant analyses made cause the tall larkspurs may be began to disperse, samples con- in Utah, Nevada, and Idaho. The more toxic following applications tained a greater percentage of fact that sheep are rarely lost to of phenoxy herbicides, particu- leaves, and oxalate percentage halogeton in Wyoming must be larly silvex and 2,4,5-T, post- responded upward accordingly. attributed to good management, treatment grazing should be re- When only pure leaf samples are better range condition, and per- stricted 2 to 3 weeks after treat- collected, one may expect solu- haps lower halogeton densities. ment and until the plants begin ble oxalate content to exceed Type of Livestock Poisoned.- to dry and lose their palatability. 30% from late August or early For almost every kind of plant Summary September to frost and later, de- poison there is a difference in pending upon climatic condi- tolerance with each class of live- Distribution and seasonal tions. A leaf sample collected stock. Tolerance of cattle for al- changes of toxic compounds were near Cisco, Utah, in November kaloids is particularly low. A studied in five poisonous range contained 38.25% soluble oxa- dose of larkspur fatal for cattle, species. Concentrations of the lates, the highest concentration based on body weight, may or poisons declined with maturity that we have found. may not even produce symptoms in two tall larkspurs; remained The toxicity of the dead plants in sheep. The reasons for these relatively unchanged in western during the winter is largely de- differences are not known. Ap- falsehellebore and halogeton; and pendent upon weather. Wind- parently the microflora of the peaked at flowering in low lark- storms, hail, and heavy rain will sheep’s digestive system are spur. With the exception of low remove leaves from standing more efficient in breaking down larkspur, the majority of the plants, reducing oxalate content. or detoxifying alkaloids. Cattle toxic principle was always found Rain will leach some soluble oxa- escape halogeton and falsehelle- in the leaves. lates from the leaves. A record bore poisoning largely because The toxicity of tall and dunce- November rainfall occurred they avoid these species. The few cap larkspur was closely deter- throughout Northern Utah from authenticated examples of halo- mined by stage of maturity. November 12 through November geton poisoning in cattle were These species tend to be more 25, 1965. The leaching effect of reported from an area where this poisonous later in the season if this precipitation may be noted weed constituted virtually the their emergence is delayed by in the markedly decreased solu- only available herbage. late snow melt, or if subsequent ble oxalate content in leaves Herbicides. - Two herbicides, growth is retarded by cold collected on November 23 (Table 2,4,5-trichlorophenoxyacetic acid weather. As elevation increased, 3). If fall and winter precipita- (2,4,5-T) and 2- (2,4,5-trichloro- duncecap larkspur contained a tion is light, the leaf-seed-sepal phenoxy) propionic acid (sil- greater concentration of alkaloids fraction may contain more than vex), increased alkaloid content at any given date. 30% soluble oxalates as late as in tall larkspur (Williams and LITERATURE CITED mid-February (Dye, 1956). Since Cronin, 1963) and duncecap lark- dead halogeton remains almost spur. In some years application BEATH, 0. A. 1919. The chemical ex- as poisonous as the living plant, amination of three species of of these herbicides has doubled larkspurs. Wyo. Agr. Exp. Sta. it should be avoided at all times. the alkaloid content of the leaves Bull. 120. 36 p. Halogeton is confined largely and stems for 2 or 3 weeks after BEATH, 0. A. 1925. Chemical ex- to desert valleys; therefore, oxa- treatment. Among the many ex- amination of three . late concentration is not affected perimental herbicides evaluated Wyo. Agr. Exp. Sta. Bull. 143. by changes in elevation. Oxalates for control of western falsehelle- 22 p. occur in such copious quantities bore, only 2,4,5-T increases alka- BINNS, W., L. F. JAMES, J. L. SHUPE, that geographical distribution, as loid content. Fortunately, the low AND G. EVERETT. 1963. A congeni- it now exists, would not cause effectiveness of this herbicide tal cyclopian-type malformation in lambs induced by maternal in- notable, or significant, differ- precludes its use in controlling gestion of a range plant, Veratrum ences in the oxalate levels of this species. californicum. Amer. J. Vet. Res. halogeton. Halogeton collected None of the five best herbicides 24: 1164-1175. POISONOUS RANGE WEEDS 279

BOHMONT, D. W., A. A. BEETLE,AND tion of Common and Botanical MORTON,H. L., R. H. HAAS, AND L. C. F. L. RAUCHFUSS. 1955. Halo- Names of Weeds, Weed Society of ERICKSON. 1959. Halogeton and its geton-What can we do about it? America. Weeds 10: 255-271. control. Idaho Agr. Exp. Sta. Bull. Wyo. Agr. Exp. Sta. Circ. 48 DYE, W. B. 1956. Chemical studies 307. 24 p. (Rev.). 12 p. on Halogeton glomeratus. Weeds WILLIAMS, M. C. 1960. Biochemical CLAWSON,A. B. 1933. Additional in- 4: 55-60. analyses, germination, and pro- formation concerning larkspur KEELER, R. F., AND W. BINNS. 1964. duction of black and brown seed poisoning. Suppl. to USDA Farm- Chemical compounds of Veratrum of Halogeton glomeratus. Weeds: ers’ Bull. 988. 3 p. californicum related to congenital 8: 452-461. ovine cyclopian malformations: WILLIAMS, M. C. 1960. Effect of so- COOK, C. W. AND L. A. STODDART. Extraction of active material. dium and potassium salts on 1953. The halogeton problem in Proc. Sot. Exp. Biol. and Med. growth and oxalate content of Utah. Utah Agr. Exp. Sta. Bull. 116: 123-127. halogeton. Plant Physiol. 35: 500- 364. 44 p. KELSEY, H. P., AND W. A. DAYTON, 505. DARROW, R. A., L. C. ERICKSON, Editors. 1942. Standardized Plant WILLIAMS, M. C., AND E. H. CRONIN. W. R. FURTICK, L. G. HOLM, AND Names. Mount Pleasant Press. 1963. Effect of silvex and 2,4,5-T M. M. SCHREIBER.1962. Report of J. H. McFarland Co., Harrisburg, on alkaloid content of tall lark- the Subcommittee on Standardiza- Pa. 675 p. spur. Weeds 11: 317-319.

Emergence and Survival of Intermediate died mainly from frost damage. Spring-seeded plants died main- Wheatgrass and Smooth Brome ly from drought. In the mountain brush type in southern Idaho, Seeded on A Mountain Range’ Hull (1948) found 5 to 22% sur- vival of 4 grasses seeded at 2 A. C. HULL, JR. Range Scientist, Crops Research Division, Agricultural depths and 16 seeding dates per Research Service, U.S.D.A., Logan Utah year over a S-year period. Bleak (1959) in central Utah Highlight Hull et al. (1962) found low reported that seeds of smooth Intermediate wheafgrass and emergence and low survival of brome (Bromus inermis Leyss.) , smooth brome were seeded af 2 seeded grasses. They indicated tall oatgrass (Arrhenatherum depths and 3 seasons for 3 years fo that further information is elatius (L.) Presl) , and interme- determine the best season and depth for seeding mountain ranges. Emer- needed for successful seeding of diate wheatgrass (Agropyron i?2- gence was best from seeding in Sep- these lands. termedium (Host) Beauv.), tember. October, and June, in that seeded, in late fall or early win- order. Seeding at the 0.5- and l-inch Plummer and Fenley (1950) depths gave similar results. Low seeded six grasses in the subal- ter, germinated and produced emergence and high mortality of all pine zone in central Utah. Per- roots and shoots under a deep ireafmenfs indicate ihe need for ad- snow cover. Hull (1960) also de- ditional information on seeding cent seedling survival of the harsh sites on mountain ranges. three best species planted at six termined this for intermediate seeding seasons over a 5-year wheatgrass at a high elevation in Season and depth of seeding period was: Late spring, 26; southeastern Idaho. grasses on mountain rangelands early summer, 24; early spring, Laude (1956) subjected six may influence their emergence, 20; late fall, 14; late summer, 12; grasses in different stages of pre- survival, and productivity. On and early fall, 10. Frost heaving emergence to controlled freezing. Western mountain rangelands was the major cause of seedling Emergence decreased as the pre- death. Also in central Utah, emergence period lengthened. ICooperative research between Frischknecht (1951) seeded 16 The decreased emergence was Crops Research Division, Agricul- species on a sagebrush and on attributed to injury by low tem- tural Research Service, U. S. De- a mountain brush site. Emer- peratures and soil pathogens. partment of Agriculture, and Utah gence was best from seeding in Holmgren and Basile (1959) Agr. Exp. Station, Logan, Utah. I the early fall, early spring and found that germination of bitter- thank Glenn Carnahan and Wesley Bitters, former students who as- late fall in that order. Season of brush (Purshia tridentata sisted with field phases of the seeding made little difference in (Pursh) DC.) seeds planted 0.5 study, and E. James Koch, Biomet- survival. Sixteen to 22% of the inch or more deep was delayed rical Services, Agricultural Re- seeds produced established so that plants avoided the high search Service, Beltsville, Mary- plants on the mountain brush frost heaving loss which accom- land, who made the statistical analysis. Utah Agricultural Experi- site and 5 to 7% on the sage- panied early spring emergence ment Station Journal Paper 457. brush site. Fall-seeded plants from shallow seedings.