Branched Burr Reed

Sparganium androcladum is less variable than the similar and more common S. americanum, from which it is distinguished by its generally larger size and more robust habit; leaves stiffer, wider, more strongly keeled; inflorescence branches usually without pistillate heads, the bracts ascending; fruiting heads larger; fruits distally shiny, the beak longer and hooked. Immature fruits of S. androcladum resemble mature fruits of S. americanum. Some specimens will not key readily to either species. The complex nomenclatural history is discussed by C. D. K. Cook and M. S. Nicholls (1987).

Sparganium androcladum has an unusual, discontinuous distribution, which is wholly within the range of S. americanum, except in the central Mississippi Valley (M. L. Fernald 1922b). In the absence of convincing specimens, the presence of S. androcladum in Virginia cannot be confirmed, although E. O. Beal (1960) reported it there, and it occurs nearby in West Virginia.

Plants robust, to 1.2 m; leaves and inflorescences erect, emergent. Leaves stiff, keeled from base at least to middle, flattened distally, to 1.2 m  5--15 mm. Inflorescences: rachis (0--)1--3 branched, erect, bracts strongly ascending, not basally inflated; pistillate heads (1--)2--4 on main rachis, 0(--2) on lateral branches, axillary, not contiguous, sessile or short-peduncled, 2.5--3.5 cm diam. in fruit; staminate heads 3--8 on main rachis, 1--6 on lateral rachises, most not contiguous. Flowers: tepals often with prominent subapical dark spot, subentire to entire; stigma 1, linear. Fruits brown, proximally dull, distally shiny, subsessile to short-stipitate, fusiform, usually constricted near equator, body not strongly faceted, 5--7  2.5--3 mm, tapering to beak; beak often curved and hooked, 4--7 mm; tepals attached at base, reaching to equator or somewhat beyond. Seeds 1.

Ont., Que.; Ark., Conn., Ill., Ind., Iowa, Ky., Maine, Mass., Mich., Minn., Mo., N.H., N.J., N.Y., Ohio, Okla., Pa., R.I., Tenn., Vt., W.Va., Wis.

Flowering late spring--summer (Apr--Jul).

Shores and shallow, quiet, circumneutral waters; 0--800m.

Sparganium simplex Hudson var. androcladum Engelmann in A. Gray, Man. Bot. Northern U.S., Manual, ed. 5, 481. 1867; S. americanum Nuttall var. androcladum (Engelmann) Fernald & Eames

Sparganium lucidum Fernald & Eames, Rhodora 9 : 87. 1907
Sparganium simplex androcladum Engelm.; A. Gray, Man. ed. 5. 481, in part. 1867.
Perennial, with a rootstock ; stem erect, stout, 7-10 dm. high ; leaves strongly carinate, 3-6 dm. long, 5-12 mm. wide, firm, dark-green; inflorescence simple or somewhat branched; branches or heads axillary; bracts ascending, 2.5-4 dm. long; branches bearing one pistillate and sometimes 1-4 staminate heads, the main axis bearing 2-4 sessile pistillate and 6-10 staminate heads ; sepals spatulate, two thirds as long as the achenes, rounded or truncate, slightly erose at the apex ; fruiting heads about 3 cm. in diameter ; achenes olive-brown, shining; stipe short, about 1 mm. long; body fusiform, about 8 mm. long; beak 3-4 mm. long; stigma linear, 2.5-3.5 mm. long.
Type locality : Medford, Massachusetts.
Distribution : Ponds and streams, from Massachusetts and New York to Missouri and Illinois.

Sparganium androcladum (Engelm.) Morong, Bull. Torrey
Club IS : 78. 1888.
Sparganium americanum I&11. Bot. S. C. & Ga. 2 : 521. 1824. Not 5. americanum Nutt. 1818. Sparganium ramosum Chapm. Fl. S. U. S. 443. 1860. Not S. ramosum Huds. 1778. Sparganium simplex androcladum Engelm.; A. Gray, Man. ed. 5. 481. 1867. Sparganium simplex androgyna Meinsh. Mel. Biol. Acad. St. Petersb. 13 : 387. 1893. Sparganium americanum androcladum Fernald & Karnes, Rhodora 9 : 87. 1907.
Perennial, with a rootstock ; stem 3-10 dm. high, erect; leaves dark-green, triangular at the base, 5-10 dm. long, 5-12 mm. wide; bracts similar but barely concave at the base, slightly dilated and narrowly if at all scarious-margined ; inflorescence branched, with branches or peduncles axillary; lower branches usually with a single (sometimes no) pistillate head and 3-7 staminate ones, usually strongly geniculate ; sepals with dilated claws, two thirds as long as the achenes, their blades cuneate and erose at the apex ; fruiting heads 2-2.5 cm. in diameter ; achenes stipitate, brown, dull, their bodies fusiform, 5-6 mm. long, 3 mm. thick, terete or obtusely angular, often constricted at the middle ; stipe and beak each about 3 mm. long ; stigma linear, about 2 mm. long ; anthers linear-oblong, about 1 mm. long and one fourth as thick.
Type locality : New England.
Distribution : Shallow water, Newfoundland to Florida, Alabama, and Minnesota.