ONAGRACEAE 221 



3. LYTHRUM L. 



Flowers solitary in the axils : stamens not more than the petals. 

 Annual : flowers not dimorphous : stamens included, i. L. hyssopifolium. 

 Perennial ; flowers dimorphous : stamens of short-styled flowers exserted. 



2. L. alatum. 

 Flowers in panicled terminal spikes : stamens twice as many as the petals. 



3. L. Salicaria. 



1. Lythrnm hyssopifolium L. Hyssop Loosestrifb. (Man. p. 649 ; 

 I. V.f. 2545- ) Borders of salt marshes, Me. to Pa. and N. J. Also in Calif, 

 and S. Am. ^fat. from Eu. — Pennsylvania : Bucks, Plumsteadville. 



2. Ljrthmm alatum Pursh. Wing-angi<ed Loosestrife. (Man. p. 

 650; I. P. /. 2J46.) In low grounds, southern Ont. to Mass., Ky., S. 

 Dak. and Kans. — Pennsylvania : DEi<aware, Hay Island ; ALLEGHENY. 



3. Ly thrum Salicaria Iv. Spiked OR Purple I/OOSESTRIFE. (Man. 

 p. 650 ; I. F. y; 2549-) In swamps and wet meadows, Cape Breton Island 

 to Ont. and Del. Said to be nat. from Eu. — Pennsylvania: Northamp- 

 ton ; Bucks ; Philadelphia ; Chester ; Allegheny. 



4. PARSONSIA P. Br. 

 1. Parsonsia petiolata (L.) Rusby. Blub Wax-webd. Clammy 

 CUPHEA. (Man. p. 650; I. P. /. 2550.) In dry soil, R. I. to 111., Kans., 

 Ga. and I,a. Introd. into southern Ont. — Pennsylvania : Northampton ; 

 Bucks ; Philadelphia ; Delaware ; Chester ; Lancaster; Leba- 

 non ; Dauphin ; Franklin ; Huntingdon ; Allegheny. 



Family 3. ONAGRACEAE Dumort. Evening-primrose Family. 



Floral whorls of 4 parts or more. 

 Fruit a many-seeded capsule, opening by valves or a pore. 

 Hypanthium not prolonged beyond the ovary. 

 Seeds naked. 

 Leaves opposite : plants with creeping or floating stems. 



1. Isnardia. 

 Leaves alternate : plants with erect or ascending stems. 



2. LtrowiciA. 

 Seeds with tufts of hairs. 3. Chamaenerion. 



Hypanthium prolonged beyond the ovary. 

 Seeds furnished with tufts of hairs. 4. Epilobitjm. 



Seeds naked, sometimes tuberculate. 

 Stamens equal in length. 

 Ovules and seeds horizontal, angled. 5. OnaGRA. 



Ovules and seeds ascending, not angled. 6. Oenothera. 



Stamens unequal in length, the alternate ones longer. 



7. Kneiffia. 

 Fruit indehiscent, nut-like. 8. Gaura. 



Floral whorls of 2 parts. 9- Circaea. 



1. ISNARDIA L. 



1. Isnardia palustris L. Marsh Purslane. (Man. p. 652 ; I. P. /. 

 ^55S-) In muddy ditches and swamps, N. S. to Man., Ore., Fla., Calif, 

 and Mes..— Pennsylvania : Northampton ; Bucks ; Monroe ; Dela- 

 ware ; Chester ; Lancaster ; Franklin ; Erie ; Allegheny. 



