78 BOTANY OF LA SALLE COUNTY. 



the calyx tube cohering 1 with the ovary which is 



2 to 4 celled 

 LUDWIGIA. P, Flowers axillary; petals 4 or 0; 



stamens 4. Blooms through summer and fall; 



flowers Y. Wet lands. 

 L. alternifolia. Smooth, erect, 2/^ to 3 ft., 



branched; leaves lanceolate, acute at both ends; 



capsule squarish with winged angles. 

 Jh. Iv. polycarpa. I/eaves narrowly linear; capsule 



somewhat top-shaped, longer than calyx lobes. 

 L- palustris. Water Purselane. L/eaves opposite, 



ovate or oval, tapering into a slender petiole. 



Ditches. 

 EPILO BIUM. Willow Herb. Leaves nearly sessile; 



stem more or less tinged with purple as are the 



leaves; branches slender, fruit long, slim and 



angled. Wet lands. 

 E. strictum. Erect, 2/^ ft., covered with glandular, 



whitish hairs; petals notched. E. Mol le 5th Ed. 

 E. angustifo lium. Erect, tall, 4 to 7 ft., leaves 



scattered, lanceolate, nearly entire; flowers 



large P. petals entire. 



Jh. E. colosatum. Somewhat soft-hairy, very branch- 

 ing; leaves purple veined, flowers Pi. 1 to 3 ft. 

 E. palustre. Slender, 1 ft. or less, more or less 



branched; covered with fine hairs; leaves erect 



or nearty so, sessile, narrow lanceolate; margins 



revolute. 

 OENOTHERA. Evening Primrose. Calyx lobes 4, 



reflexed; petals 4, stamens 8, leaves- alernate, 



flowers Y. or W. 



O. biennis. Stout, erect, 1 to 5 ft., hairy. 

 O. rhombipetala. Somewhat wooly; petals broad- 

 ovate, acute. 

 Jh. O. sinua ta. More or less decumbent. 1 ft. rough, 



