

428 CERATOPHYLLACEAE 



the calyx-lobes, broadened upward, unappendaged. Stamens 10. Ovary 1 -celled : styles 

 5, alternating with the calyx-lobes. Capsule 1-celled, opening by tooth-like valves. 

 Seeds black, the embryo curved. 



1. Agrostemma Githago L. Foliage pubescent with long appressed hairs. Stems 

 erect, 2-9 dm. tall, branched, the branches erect or ascending : leaf-blades linear, 4-12 

 cm. long, acute, sessile: pedicels 0.5-2.5 dm. long : calyx pubescent like the stem ; tube 

 cylindric, 1.5-2 cm. long, 10-ribbed ; lobes linear, longer than the tube, acute : petals with 

 obovate blades 2 cm. long, rounded or notched at the apex, purple or magenta, paler at 

 the base, indistinctly nerved, shorter than the calyx-lobes : seeds angular, 2 mm. in 

 diameter, spiny-tuberculate all over. 



lu fields, common in or about grain fields throughout North America. Naturalized from Europe. 

 Summer. COKN COCKLE. CORN ROSE. 



Order 11. RANALES. 

 HerV^s, shrubs or trees. Leaves normal, often of 2 forms on aquatic plants : 

 blades simple or sometimes compound. Flowers perfect, monoecious or dioe- 

 cious, variously disposed. Calyx and corolla of distinct and separate members. 

 Androecium of usually hypogynous stamens, which are mostly more numerous 

 than the sepals. Gynoecium of 1 or several, distinct or rarely more or less united, 

 carpels. Ovary superior. Fruit various. 



Stamens usually numerous, the anther-sacs opening by slits. 



Land plants, except in CERATOPHYLLACEAE and some RANUNCULACEAE : leaf-blades not peltate. 

 Flowers perfect or monoecious, if dioecious on neither vines nor herbs with simple leaves. 

 Plants with minute axillary monoecious flowers : anthers with 



horn-like appendages. Fam. 1. CERATOPHYLCLA 



Plants with perfect or rarely dioecious flowers : anthers not 



with horn-like appendages. 

 Carpels 1 or more, distinct, at least at maturity. 



Sepals 3-15 : petals about as many : plants if shrubby not 



with pulpy fruit : endosperm even. Fam. 2. RANUNCULACEAE. 



Sepals 5: petals G: fruit pulpy : endosperm channeled. Fam. 3. ANONACEAE. 

 Carpels more or less coherent or united into cone-like struc- 

 tures, or immersed in the pulpy receptacle. 



Sepals yalvate. Fam. 3. ANOXACEA K. 



Sepals imbricated. Fam. 4. MAGNOLIACKAK. 



Flowers dioecious : vines with simple leaves. Fam. 5. MENISPERMACEAE. 



Water plants : emersed or floating leaves with peltate blades. 

 Carpels several and distinct. 



Carpels not in a fleshy receptacle : sepals and petals 3 or 4 each : 



stamens 3-18. Fam. 6. CABOMBACEAE. 



Carpels immersed in a fleshy receptacle : sepals and petals nu- 

 merous : stamens indefinite. Fara. 7. NELUMRONACKAK. 

 Carpels united into a compound pistil. Fam. 8. NYMPHAKACKAK. 

 Stamens few and definite, the anther-sacs opening by hinged valves, 



except in Podophyllum. Fam. 9. PODOPHYLLACKAK. 



FAMILY 1. CERATOPHYLLACEAE A. Gray. HORNWORT FAMILY. 



Aquatic perennial herbs, with submersed jointed branching stems. Leaves 

 whorled : blades 2-cleffc or finely dissected, the filiform segments forking. 

 Flowers monoecious, inconspicuous, axillary, sessile. Calyx herbaceous. Sepals 

 6-12, narrow, rather valvate, toothed or cleft at the apex. Staminate flowers 

 with 10-24 stamens crowded on a flat or convex receptacle : filaments very short : 

 anthers opening by longitudinal cracks, the connective produced into an often 

 2-3-toothed fleshy appendage. Pistillate flowers without staminodia. Ovary 

 1-celled, sessile : style cylindric. Ovule solitary, anatropous, pendulous. Fruit 

 nut-like, somewhat flattened, 1-celled, naked : pericarp leathery or crustaceous. 

 Seed pendulous, with a membranous testa. Endosperm wanting. Embryo 

 straight. 



CBRATOPHYLLUM L. 



Characters of the family. The plants flower mainly in the summer. 



Achenes unarmed. 1. ('. subincrxurn . 



Achenes armed on the edges with spines. 



Leaves 6-9 in a whorl ; segments spiny-toothed : achenes with a spine on either side of the base. 



2. C. dcmersum. 



Leaves 9-12 in a whorl ; segments bristly-toothed : achenes fringed with spines. 3. ('. echinatnm. 





