828 LYTHKACEAE 



Leaves mostly opposite. 



Leaf-blades oblong to orbicular or rarely cuneate. 



Hypanthium trumpet-shaped : leaf-blades short-petioled. 1. L. Vulneraria. 



Hypanthium tubular or nearly so : leaf-blades sessile. 2. L. ovalifolium. 



Leaf-blades linear. . 3. L. lineare. 



Leaves mostly alternate. 



Leaf-blades narrowed at the base. 



Larger leaves with linear blades : sepals broadly triangular, the accessory 



teeth short and stout. 4. L. linearifolium. 



Larger leaves with elliptic or lanceolate blades : sepals mucro-like, the acces- 

 sory teeth subulate. 

 Leaf -blades thick, those of the branches numerous, approximate, mostly 



less than 1.5 cm. long : hypanthium 6-8 mm. long. 5. L. lanceolatum. 



Leaf blades thin, those of the branches few, mostly over 1.5 cm. long : hy- 

 panthium 3-5 mm. long. 6. L. Curtissii. 

 Leaf-blades rounded or cordate at the base. 7. L. alatum. 



1. Lythrum Vulneraria Ait. Stems more or less creeping, spreading or ascending, 1-12 

 dm. long, very slender : leaves opposite ; blades leathery, oblong to oval, 0.5-1 cm. long, 

 obtuse, flat, rounded or cordate at the base, short-petioled : flowers axillary, about 1 cm. 

 broad : hypanthium 5-6 mm. long, short-pedicelled, slightly trumpeted-shaped, fluted : 

 sepals low, mucronate, the accessory teeth subulate, ascending : petals purple, cuneate- 

 obovate, obtuse : stamens in short-styled flowers, exserted : capsules 4-7 mm. long. 



On margins of ponds and swamps, Florida to Texas and Mexico. Spring to fall. 



2. Lythrum ovalifolium Engelm. Steins erect 'or decumbent, 1-3 dm. tall, simple 

 or branched, the branches very slender : leaves opposite ; blades oblong to orbicular- 

 oblong, or the lower ones cuneate, 1-1.5 cm. long, obtuse or acutish, entire, sessile : flowers 

 axillary, 7-9 mm. broad : hypanthium nearly tubular, 4 mm. long, fluted-angled : sepals 

 short, apiculate, shorter than the subulate accessory teeth petals violet, cuneate, rounded at 

 the apex, spreading : stamens exserted : capsules narrowly oblong, included : seeds 0.4 mm. 

 in diameter. [L. alatum var. pumilum A. Gray.] 



In damp soil, Texas. Spring and summer. 



3. Lythrum lineare L. Stems wand-like, 3-12 dm. tall, 4-angled, branched above : 

 leaves opposite ; blades linear, 1-4 cm. long, leathery, acute, or the lower ones obtuse, 

 slightly revolute, sessile : flowers dimorphous, 7-8 mm. broad : hypanthium rather short, 

 about 4 mm. long, trumpet-shaped, fluted : sepals triangular, awn-tipped, about as long as 

 the short horn-like accessory teeth : petals cuneate or cuneate-oblong, rounded at the apex, 

 pale purple or pink : stamens included, or exserted in the case of short-styled flowers : 

 capsules oblong-clavate, hardly 4 mm. long : seeds 0.8 mm. long. 



In or near salt meadows, New Jersey to Florida and Texas. Summer. 



4. Ly thrum linearifolium (A. Gray) Small. Stems slender, simple, or branched at 

 the base or above, angled, the branches erect or spreading : leaves alternate, firm ; blades 

 linear or linear-oblong, acute or acutish at the apex, slightly revolute, sessile : hypanthium 

 trumpet-shaped, 5 mm. long : sepals broadly triangular, acute, their accessory teeth short 

 and stout : corolla nearly 1 cm. broad : petals obovate, rounded at the apex, purple, drying 

 violet-purple : capsules narrowly clavate-oblong. \_L. alatum var. Linearifolium A. Gray.] 



In moist ground, Texas to Arizona and Mexico. Spring to fall. 



5. Lythrum lanceolatum Ell. Stems erect or ascending, 6-16 dm. tall, sharply 

 angled or slightly winged, usually with numerous strongly ascending branches : leaves 

 alternate or some of the lower ones opposite ; blades elliptic to linear-elliptic, 1-6 cm. long, 

 acute at the apex, narrowed to the sessile base, those of the branches numerous, approxi- 

 mate mainly about 1 cm. long : hypanthium slender, 6-8 mm. long, fluted : sepals mucro- 

 like, acute, their accessory teeth subulate, ascending : corolla violet-purple, 8-10 mm. broad : 

 petals rose-purple, obovate or cuneate-obovate, obtuse : stamens included : capsule narrowly 

 oblong, included : seeds 0.8 mm. long. 



In low grounds and in swamps, South Carolina to the Indian Territory, Florida and Texas. Summer. 



6. Lythrum Curtissii Fernald. Similar to L. lanceolatum in habit, but less rigid. 

 Stem wing-angled, the branches pliable : leaves mainly alternate ; blades relatively thin, 

 those of the main stem 2-5.5 cm. long, those of the branches relatively few, distant, usually 

 about 2 cm. long : hypanthium 3-5 mm. long : sepals somewhat longer than the bristle- 

 like teeth : petals pale purple. 



In low grounds and marshes, Georgia and Florida. Summer and fall. 



7. Lythrum alatum Pursh. Stems erect or ascending, 3-13 dm. tall, angled and 

 often slightly winged, much branched, the branches erect or ascending : leaves alternate, 

 or some of the lower ones opposite ; blades lanceolate, oblong or ovate-lanceolate, 1 

 cm. long, acute at the apex, rounded or cordate at the more or less clasping base, sessile : 

 flowers conspicuous, dimorphous, on short 2-scaled pedicels : hypanthium 5-8 mm. long, 



