MOXOPETALOUS EXOGENOUS PLANTS. 313 



CEPHALANTHUS, L. Button-bush. 



Calijx obconical, 4-toothed ; corolla tubular, 4-cleffc, im- 

 bricated in the bud; stamens 4; style slender, exserted ; 

 stigma capitate ; fricit dry, obconical, separating from the 

 base into 2-4 one-seeded carpels; seeds pendulous; alhu- 

 men horny. — Aquatic shrubs, with oval or lanceolate 

 leaves, short entire stipules, and white flowers collected 

 into a globose long-peduncled head ; receptacle hairy. 



C. occiDENTALis, L. Smooth, or the young branches 

 and lower surface of the ovate-oblong acute leaves pubes- 

 cent ; peditncles terminal, and in the upper axils. Ponds 

 and marshes. Stem 4°-12° high; leaves petioled, 3-5' 

 long, sometimes 3 in a whorl ; heads 1' in diameter. 



MITCHELLA, L. 



Flowers by pairs, with their ovaries united; calyx 

 4-toothed ; corolla funnel-shaped, 4-lobed, hairy within, 

 valvate in the bud; stamens 4; 5i??/?e slender; stigmas 4:', 

 fruit composed of two 4-seeded fleshy drupes united, 

 crowned with the 4-toothed calyx. — A smooth creeping 

 evergreen shrub, with small broadly-ovate leaves, minute 

 stipules, and fragrant w^hite iQvmmdl floioers. 



M. REPENS, L. Shady woods. Stem l°-2° long; leaves 

 6"-10" long, mostly somewhat cordate, shining above, on 

 slender petioles ; corolla i' long; fruit red. 



OLDENLANDIA, Plum. Bluets. 



Floivers tetYSLmeroiis; m??/:r 4-toothed, persistent ; corol- 

 la funnel-shaped, salver-shaped, or wheel-shaped, 4-lobed, 

 imbricated in the bud ; stamens 4 ; stigma mostly 2-lobed ; 

 capsule roundish or obcordate, 2-celled, opening loculicid- 

 ally at the apex, which is often free from the calyx ; seeds 



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