seeds are found about August 20, and by the end of the first week in September the whole seed crop has ripened. Data on the vitality of the seeds were obtained only in 1909, when an average from three tests gave 27.5 per cent germination.

As its common name implies, sheep sedge is a highly relished sheep forage. The leaves are tender and juicy throughout the summer, and the plant seems to be consumed with about the same eagerness at all times during the growing season. Horses, too, graze this sedge with unusual eagerness, consuming flower stalks with the same avidity as the leaf blades. Since sheep sedge is restricted to moist habitats it is, of course, not very abundant, but in favorable situations it holds its own remarkably well, and it is not uncommon to find it predominating over other sedges and more fastidious species almost to their entire exclusion.

Three other species, usually called marsh or water sedges, C. festiva, C. vulgaris bracteosa, and C. tolmiei subsessilis, are, on account of their general appearance, forage value, and distribution, often confused with sheep sedge. Of these, Carex festiva resembles it most, but differs in many minute characters (compare Plates XXVIII and XXIX). The leaves of Carex festiva are much broader and coarser, and are rough on the edge, and the color of the plant is light green. The other two species, C. tolmiei subsessilis and C. vulgaris bracteosa (Plates XXX and XXXI) have much more elongated spikes, of a brown-black color, which alone should eliminate confusion. The latter attains about twice the height of the former, and its culms are more acutely angular. The forage value of all three species is practically the same, though C. vulgaris bracteosa is relatively less abundant than the other two. C. tolmiei subsessilis remains palatable to stock for a longer period than either of the others, but is more abundant in the alpine or upper subalpine regions, and therefore matures. later, being of little importance as forage when the other species are of highest value.

ELK GRASS.

(Carex geyeri.)

Of the dry-land sedges, elk grass is by far the most abundant. It occurs in the Canadian and Hudsonian zones, often as the predominating species on exposed hillsides, and is among the earliest of the herbs to send forth its leaf blades. Many hillsides have been almost wholly vegetated by this species.

Since elk grass produces new plants by stolons the growth is dense and segments of a tuft are almost inseparable (Plate XXXII). The slender, angled, rough culms, about 1 foot high, exceed but slightly the harsh and rough-edged leaf blades. The spikes are slender, borne at the summit of the culm, the staminate flowers usually appearing above, and the pistillate (1 or 2 in number) below.

The very nature of the habitat in which elk grass succeeds indicates its unusual ability to withstand low moisture conditions. The soil in which it grows is a coarse gravelly one, which liberates the water more readily than finer soils. Drought tests resulted in the extensive wilting of all leaf blades of the plant only when the water content was reduced to 6.5 per cent, and in some instances slightly lower. This places elk grass very near the head of the list in its ability to exist under adverse moisture conditions. Flower stalks begin appear during the last week in June, and by July 20 practically all are out. About the time that the last flower stalks are sent up matured seeds are found. By August 15 the seed crop is almost entirely ripened and disseminated. The seed has about average viability, the tests in 1907 and in the two subsequent seasons showing germinations of 6, 26, and 32 per cent, respectively.

In the forepart of the season elk grass is grazed with a certain amount of avidity, though practically every other grass species is preferred to it. It is only eaten by sheep up to about August 1, unless the stock are starved. After that date the leaves become so tough, hard, and fibrous that even horses will not graze it if other forage is available. Sheep always scatter widely when feeding upon it, doubtless searching for more palatable food.

RUSH.

(Juncus parryi.)

Among the several species of rushes found on the highland ranges Juncus parryi is commonly met with, and in value is typical of other species which are abundant in the region studied.

Like most rushes of the drier situations, Juncus parryi is tufted, and has woody, fibrous, deep-spreading roots capable of withstanding an unusual amount of abusive grazing. The stems are thin and wiry, from 4 to 10 inches long, and the cylindrical leaves are about half the length of the flower stems (Plate XXXIII); the inflorescence, usually 2 or 3 flowered, is surpassed by a bract similar to the leaves. Juncus parryi is confined to the high ranges. In the Hudsonian zone it occurs extensively in open, exposed situations on well-drained, often poorly disintegrated soils. It is usually associated with elk grass (Carex geyeri) and is just about as drought resistant, the specimens studied not wilting beyond recovery until the soil-moisture content was reduced to from 5.5 to 7 per cent. Above timber line it is found in considerable abundance in association with typical alpine species.

On the lowest areas on which the plant occurs the flower stalks begin to show about July 10, and by August 5 nearly all have been sent up. Matured seeds are usually not found before August 25.

The viability of the seed crop has not been determined. Other species of the same genus growing in similar habitats have given results that are comparatively low. (See Table 2, p. 58.)

The forage value of Juncus parryi is not especially high, resembling that of elk grass more than any of the other species described. Like the latter, this rush is eaten to some extent early in the season, but soon becomes extremely tough and unpalatable. For this reason, if other forage is available, it remains untouched by horses and sheep. Since it is grazed to such a limited extent, practically nothing is known of its nutritive qualities.

A number of other rushes of minor importance occur throughout the mountains, the majority in moist soils.

WOOD RUSH.

(Juncoides parviflorum.)

This genus is closely related to the rushes and resembles them in general character. It may be distinguished from the latter, however, by the leaf sheaths, which in this genus are closed and in the rushes open. Further, the seed vessel or capsule of Juncoides bears 3 seeds while in Juncus the capsule is many-seeded. About 60 species are on record and they are widely distributed.

Wood rush is a tufted, hardy, perennial plant, the stems, commonly 2 to 3 in a tuft, 1 to 2 feet high. As shown in Plate XXXIV, the grasslike flat leaves, usually about one-third the length of the flower stems, are wide and sharp-pointed; inflorescence a loose panicle, commonly 2 to 4 inches long, its lowest bract foliaceous, usually less than the length of the panicle; flowers borne singly or 2 to 3 together on the branches of the panicle on slender pedicels or stalks. Wood rush is strictly a high-range plant, and while found to a limited extent in the warmer situations of the Arctic-alpine zone it is almost entirely confined to the Hudsonian zone. The densest and most luxuriant growth occurs in the semihumid soils of exposed situations, though it is often found in considerable abundance both in well-drained soils and on forested areas. Its most common associate is tufted hair-grass (Deschampsia caespitosa) and black hair-grass (D. atropurpurea). In water requirements it is similar to the two species of hair-grasses, neither of which may be classed as highly drought resistant. It is usually unable to recover from a wilted condition in its natural habitat when the water content of the soil drops to between about 10 and 12.5 per cent.

Since the plant grows only on the higher and relatively moist soils, the flower stalks seldom begin to show until July 20. Three weeks later practically all have been produced. Matured seeds are found about the time that the last flower stalks are sent forth, though the