Very common in New England and the east generally, where the type of robustum is absent. Toward the west it runs into the next, but it is occasionally found, even to the valley of Mexico (Pringle 3329). Approaches typical hiemale in its long sheaths and size, and differs little except in the cross-bands of silex. Found usually in moist sand near a watercourse; at times on high sandy banks. It is by no means certain that this is the variety described by Engelmann under this name, but from the brief description he gives it seems safe to assume that it is. Two branched forms are found, as follows:
a. Forma ramosum f. nov. (f. Ramigerum A. A. E., in Gilbert’s list, p. 26, not A. Br. in Sched., which normally branches at the 3 to 5 middle nodes.) Stems issuing one to several branches from the upper nodes after the death of the top of the main axis; teeth usually persistent and leaves centrally grooved. b. Forma polystachyum Prager. Stems issuing small spiciferous branches late in the season. As remarked by Mr. Gilbert (List, p. 26), these forms are seldom found together and many patches show neither.
The stems of this variety persist at least three years and probably longer. I have found but two causes of death, old age not appearing as a factor. Both are fungoid. After the stem has persisted for a time small white patches appear under the epidermis of the upper internode. These increase in number and the internode finally dies, not, however, till the second one shows the disease. This may continue till the whole stem succumbs. The other fungus is a smut that breaks out in small pustules, finally opening in black patches the size of the head of a pin or smaller. They are usually numerous and the stem dies rapidly.
The growth of the stem is indeterminate, but as each succeeding section is a little smaller than the one below, the time arrives in the history of each when no more can be pushed out and the growth ceases. The undeveloped internodes soon die and thus the stem, if it grows at all, must put its energy into branches, as the silex coating prevents its increase in diameter.
9. Robustum (A. Br.) E. robustum A. Br. Stems 3 to 6 feet tall, 2 to 6 lines wide, 16 to 48 angled, simple or branched the second year; ridges rough with cross-bands of silex; grooves naked with a smooth coat of silex, and when young with a thin white scurfy coat that soon falls off; sheaths tight to the stem, or recurved and deciduous in fragments in age, as broad as long, soon developing a black girdle at base, an ashy or pinkish one through the middle and a black one above, the last usually very small, all variable in breadth and intensity of color; leaves linear, sharply 3 angled; commissural groove not widened above; teeth more or less persistent for a season, seldom torn off by the growth of the stem, articulated to the leaves, cohering, in groups, brown centrally, with tawny margins ½ their height, ending in filiform usually flexuous appendages, the edges beset with unicellular bristles; branches variable in number and length, the sheaths mostly like those of the stem except the teeth always persist and the leaves are usually grooved centrally; spikes usually green, oval, up to an inch long and half as wide, sharply apiculate. Ramosum and polystachyum forms occur in this as well as in affine.
Rare east of the Mississippi, where it is replaced by var. affine. Very common west, where it has been reported from nearly every State. I have seen it from but six localities in the Eastern States, Wallingford, Pa., T. C. Palmer; Towson, Md., C. E. Waters; Peoria, Ill., F. E. McDonald; Illinois, without locality, Dr. Brendell; Mattsville, Ind., Guy Wilson; Sarnia, Mich., C. K. Dodge; accredited to New Jersey by Milde, and also found in the Himalayas.
Var. minus Eng. is simply the same thing reduced, often growing with it. As there is already a variety minus of hiemale this name will not stand, and the form is of too little moment to merit another.
Stems of this can usually be recognized at a glance, but it is hard to embody the description in words that will enable one to separate it from affine at once. From Californicum it can only be separated by use of a lens, as their appearance is identical.
10. Californicum Milde. Plants of various appearance, now 15 inches high and 4 lines wide, now 7½ to 8 feet tall and 8 lines wide, 25-40 angled; the ridges with two distinct rows of tubercles or occasionally with transverse bands of silex, the grooves abundantly supplied with rosulæ, either in regular rows or scattered, often indistinct on old stems because of a heavy deposit of silex; sheaths as broad as long, with a broad or narrow black or dark brown ring just above the base, an ashy band in the middle and another usually narrow dark band at top. In young plants the sheaths are usually concolorous with the stem save for the terminal band; leaves linear, 3-angled with two rows of tubercles on the middle angle; commissural groove narrow, slightly or not at all widened above; teeth persistent, dark brown, firm, united two-thirds their height by brown borders; or brown-centered, flexuous, membranous-bordered, united or free, or early deciduous, leaving only a small dark brown spot at the tip of the leaves; branches none or few, short or up to 18 inches long, fruited or not, on the upper part of old stems.
Type. California Balfour, 1854. I have seen it from the following localities: California: Sacramento, Wilkes Exp. (Sheaths black, teeth persistent, near var. Javanicum); Berkeley, W. C. Blasdale (very stout, often with two rows of stomata); San Rafael, Munson & Hopkins (like last, but with one row of stomata). Arizona: Cedar Ranch, MacDougal. Nevada: Humboldt Mts., Watson. Utah: Fish Lake, Jones; Glenwood, Ward. Idaho: Peter Creek, Sandberg; Salmon, Henderson. Oregon: Port Discovery, Wilkes Exp. Washington: Tacoma, Flett; Klickitat Co., Suksdorf. British Columbia: New Westminster, A. J. Hill. (No rosulæ, occasionally two rows of stomata, extraordinarily thick coating of silex.)