NYSSACEAE. 205 



Stamens 2, alternate with the petals. Ovary 1-2-celled. Fruit obovoid, usually 

 bristly with hooked hairs. 



1. C. lutetiana L. Plants 3-6 dm. tall: leaf-blades ovate, 5-10 cm. long, 

 remotely denticulate: pedicels 4-8 mm. long: corolla about 3 mm. broad: fruits 

 broadly obovoid, about 4 mm. long, with stiff hairs. — Common, in woods and 

 thickets. — Sum. — Enchanter 's-nightshade. 



Family 4. GUNNERACEAE. Water-milfoil Family. 



Perennial, or rarely annual, aquatic or amphibious herbs. Leaves 

 alternate or whorled: blades entire to dissected, often of 2 kinds on the 

 same plant. Flowers perfect or monoecious. Calyx of 2-4 sepals. 

 Corolla of 2-4 small petals, or wanting. Androeeium of 1-8 relatively 

 large stamens. Gynoecium of 1, or of 2-A, sometimes united, carpels. 

 Ovary inferior. Stigmas 1-4. Fruit an angled, ribbed, or winged nutlet 

 or drupe. 



1. PKOSEE.PINACA L. Herbs with creeping stems. Leaves alternate: 

 blades toothed or pectinate-pinnatifid, the lower ones more finely dissected. 

 Flowers perfect, axillary. Petals wanting. 



1. P. pectinata Lam. Leaf -blades pectinate or pectinate-pinnatifid: fruits 

 3,5-4 mm. long, the angles rather obtuse. — M. Rare, in swamps along the 

 Conestoga near Lancaster. — Limestones. — Sum. ■ — ■ Mermaid-weed. 



Order AMMIALES. 



Herbs, shrubs, or trees, or vines. Leaves alternate or opposite : blades 



simple or compound. Flowers perfect, polygamous, or dioecious, often 



borne in umbels. Calyx of typically 5 small sepals surmounting the 



hypanthium. Corolla of typically 5 petals, or wanting. Androeciimi of 



as many stamens as sepals. Gynoecium 2-carpellary or rarely several-1- 



carpellaiy. Ovary inferior. Fruit drupaceous or baccate, or diy (a 



cremocarp). 



Fruit drupaceous or baccate : gynoecium 1-several-carpellary, if 2-carpellary, stig- 

 mas introrse. 

 Styles single or united: ovule with a dorsal raphe: leaves mostly opposite; 



blades entire or merely toothed. Fam. 1. Nyssaceae. 



Styles distinct : ovule with a ventral raphe : leaves mostly 



alternate ; blades lobed or compound. Fam. 2. Hederaceae. 



Fruit dry, a cremocarp : gynoecium 2-carpellary : stigmas 



terminal. Fam. 3. Ammiaceae. 



Family 1. NYSSACEAE. Dogwood Family. 



Shrubs or trees, or rarely partly herbaceous plants. Leaves opposite 

 or alternate : blades usually entire. Flowers perfect or unisexual, borne 

 in naked or involucrate, open or congested cymes. Calyx of mostly 4 or 5 

 sepals. Corollas of 4 or 5, or rarely more, petals, or wanting. Androeeium 

 of usually as many stamens as sepals. Gynoecium of 1 carpel or of 2-4 

 united carpels. Styles single or ui:iited. Fnait mostly a drupe, or baccate. 



Flowers dioecious or polygamo-dioecious : stigmas lateral : drupe with a 1-celled, 



1 -seeded stone. 1. Nyssa. 



Flowers perfect : stigmas terminal : drupe with a 2-celled, 2-seeded 

 stone. 

 Flowers in open cymes, not subtended by an involucre : fruit 



surmounted by the style, globular, not red. 2. Svida. 



Flowers in a head, subtended by a large involucre : fruit sur- 

 mounted by the calyx, elongate, red. 3. Cynoxylon. 



