2. Myriophyllum VerticillÓtum L. Whorled Water-Mil Foil

Fig. 3082

Myriophyllum verticillatum L. Sp. Pl. 992. 1753.

Submerged leaves in crowded whorls of 3's and 4's, the capillary divisions very slender, sometimes finer than those of M. spicatum, about 10 pairs, 1'-1 1 /2' long, often minutely scabrate. Floral leaves pectinate or pectinate-pinnatifid, longer or shorter than the flowers; spike 2'-6' long; petals of the staminate flowers 4, purplish; stamens 8; fruit 1"-\\" long, and about 1" thick, somewhat gibbous at the base.

In both deep and shallow water, Quebec and Ontario to New York, west to Minnesota and British Columbia. Also in Europe and Asia. Myriad-leaf.

2 Myriophyllum Verticill Tum L Whorled Water Mil F 1424

3. Myriophyllum Alterniflˇrum Dc. Loose-Flowered Water-Milfoil

Fig. 3083

Myriophyllum alterniflorum DC. Fl. Franc. Suppl. 529. 1815.

Submerged leaves usually in whorls of 3-5, occasionally scattered, the pinnate divisions capillary, 3"-5" long. Spikes short, 1'-2' long, numerous or several on the branching stems; uppermost floral leaves ovate or linear, entire or minutely toothed, smaller than the flowers, early deciduous; flowers mostly in pairs or solitary; petals of the staminate flowers 4, longer than the stamens, pale rose-color, deciduous; stamens 8; fruit nearly 1" long, slightly less than 1" thick; carpels rounded on the back, with a deep groove between them.

In deep water, Newfoundland to eastern Massachusetts and Ontario. Greenland. Common in Europe.

3 Myriophyllum Alternifl Rum Dc Loose Flowered Wat 1425

4. Myriophyllum TenÚllum Bigel. Slender Water-Milfoil

Fig. 3084

Myriophyllum tenellum Bigel. Fl. Bost. Ed. 2, 346. 1824.

Stems slender, scape-like, nearly leafless, simple, erect, 1 1/2'-6' or "rarely 12' high. Rhizome creeping, sending up many sterile stems; flowers alternate, solitary; uppermost bracts obovate, often longer than the monoecious flowers, the lower oblong, often shorter, the lowest minute or wanting; petals 4, purplish, longer than the 4 stamens; fruit i" long and about as thick at the top, sometimes enlarged at the base; carpels rounded or obtusely angled on the back, separated by a shallow groove.

Sandy bottoms of ponds and streams, Newfoundland to New Jersey, Pennsylvania, Ontario and Michigan.

4 Myriophyllum Ten Llum Bigel Slender Water Milfoi 1426

5. Myriophyllum H¨mile (Raf.) Morong. Low Water-Milfoil

Fig. 3085

Burshia humilis Raf. Med. Rep. (II.) 5: 361. 1808. Myriophyllum ambiguum Nutt. Gen. 2: 212. 1818. Myriophyllum humile Morong, Bull. Torr. Club 18: 242. 1891.

Typical form terrestrial, 1'-1 1/2' high, rooting in mud on shores. Leaves linear, entire or pectinate. Floating forms with stems often 12' long, branched, with all or most of the leaves pectinate into capillary segments; these produce the typical form if they take root; petals 4, purplish; stamens 4; fruit usually less than 1" long and about as thick at base, its carpels smooth, or rarely slightly roughened, separated by a shallow groove.

In ponds, Maine to Rhode Island, Maryland and recorded west to Illinois and Tennessee. Variable in appearance, but the variations are manifestly only conditions of the plant dependent upon its environment.

5 Myriophyllum H Mile Raf Morong Low Water Milfoil 14275 Myriophyllum H Mile Raf Morong Low Water Milfoil 1428

6. Myriophyllum heterophỳllum Michx. Various-leaved Water-Milfoil. Fief. 3086.

Myriophyllum heterophyllum Michx. Fl. Bor. Am. 2: 191. 1803.

Floral leaves in whorls of 3's to 5's, linear, ovate or lanceolate, serrate or rarely entire, much longer than the flowers. Submerged leaves subverticillate or scattered, crowded, pectinate-pinnatifid, about 10" long, the divisions 6-10 pairs, capillary; flowering spike elongated (sometimes 18' long); petals 4; stamens 4, rarely 6; fruit 1" long, and slightly longer than thick; carpels 2-keeled on the back, their sides convex, usually slightly scabrous.

In ponds, Ontario and New York to Florida, west to Minnesota, Texas and Mexico.

Myriophyllum hippuroides Nutt., with narrower floral leaves and fruit slightly longer, a species of the Pacific United States, is recorded from southern Ontario.