PRIMULACEAE 901 



many stamens as there are corolla-lobes and opposite them, adnate to the tube 

 or on the calyx, rarely alternating with staminodia. Filaments sometimes united 

 at the base. Anthers 2-celled : sacs opening introrsely. Gynoecium a single 

 pistil. Ovary free or nearly so, 1-celled, with a free central placenta. Style 

 entire. Stigma entire or lobed. Ovules amphitropous, numerous or two. 

 Fruit a 1-celled capsule opening by 2 to 8 valves. Seeds 2 or many, with a 

 smooth roughened or furrowed testa. Endosperm fleshy or horny. Embryo 

 usually transverse. 



Corolla-lobes erect or spreading. 

 Lobes of the corolla imbricated. 



Ovary superior : plants with dissected leaf-blades. ' 1. HOTTONIA. 



Ovary partly inferior : with entire leaf-blades. 2. SAMOLUS. 



Lobes of the corolla valvate or convolute. 

 Capsules opening lengthwise. 



Staminodia wanting : filaments united at the base. 3. LYSIMACHIA. 



Staminodia present : filaments distinct or essentially so. 4. STEIRONEMA. 



Capsules circumscissile. 



Corolla longer than the calyx : filaments pubescent, adnate to the base of the 



corolla. 5. ANAGALLIS. 



Corolla shorter than the calyx : filaments glabrous, adnate to the corolla- 

 tube. 6. CENTUNOULUS. 

 Corolla-lobes reflexed. ^ 7. DODECATHEON. 



1. HOTTONIA L. 



Aquatic herbs, with glabrous foliage. Stems submerged. Leaves numerous, the sub- 

 mersed with pinnately dissected blades : petioles often inflated. Scapes erect, the inter- 

 nodes inflated. Bracts whorled. Flowers whorled at the nodes, pedicelled. Calyx persist- 

 ent : lobes 5, narrow, imbricated, longer than the tube. Corolla white, salverform : 

 tube longer than the 5 imbricated lobes of the spreading limb. Stamens 5, adnate to the 

 corolla-tube below the middle : filaments about as long as the anthers. Ovary sessile : 

 style filiform : stigma capitate. Ovules numerous, anatropous, inserted on a rounded 

 stalked placenta. Capsule membranous, partially 5-valved. Seeds numerous, slightly 

 angular. FEATHERFOIL. 



1. Hottonia inflata Ell. Stems submerged, spongy, 2-6 dm. long, leafy, simple or 

 branching : leaf-blades ovate to oblong in outline, 5-10 cm. long, finely divided almost to 

 the middle into linear-filiform segments : scapes tufted, 1-3 dm. long, jointed, the lower 

 joint often 2.5 cm. thick, the upper ones successively smaller : bracts linear or linear-spat- 

 ulate, 5-15 mm. long : flowers whorled at the nodes : pedicels variable in length, 0.3-5 cm. 

 long : calyx often minutely glandular ; tube very short ; lobes linear, 5-10 mm. long, 

 rather obtuse : corolla white, 3 mm. long, shorter than the calyx, the lobes oblong, obtuse, 

 as long as the tube : stamens included : capsules subglobose, about 3 mm. in diameter, 

 glabrous : seeds about 0. 5 mm. long. 



In ponds and ditches, Massachusetts to New York, Florida and Louisiana. Spring and summer. 



2. SAMOLUS L. 



Annual or perennial caulescent herbs. Leaves alternate, various : blades entire. 

 Flowers white or pink, in simple or panicled bracted or naked racemes. Sepals united at 

 the base, persistent. Corolla perigynous : tube very short, the rounded lobes of the limb 

 imbricated. Stamens 5, adnate to the corolla-tube, sometimes alternating with 5 narrow 

 staminodia in the sinuses of the corolla-lobes. Anthers cordate, erect. Ovary 1-celled : 

 stigma obtuse or capitate. Ovules numerous, half-anatropous, in a subglobose placenta. 

 Capsule barely, if at all, elongated, 5-valved at the apex. Seeds numerous. WATER 

 PIMPERNEL. BROOK WEED. 



Racemes sessile or nearly so : staminodia at the sinuses of the corolla. 1. S. floribundut. 

 Racemes long-peduncled : staminodia wanting. 



Peduncles glandular-pilose : corolla 4-5 mm. broad ; lobes broadly cuneate. 2. S. cuneatus. 

 Peduncles glabrous : corolla 6-9 mm. broad ; lobes suborbicular. 



Glaucous : corolla 8-9 mm. broad. 3. /S. alyssoide*. 



Bright green : corolla 6-7 mm. broad. 4. S. ebracteatus. 



1. Samolus floribundus H.B.K. Light green, glabrous, 1-6 dm. tall. Stems 

 simple or diffuse : leaves few ; blades obtuse, mainly 3-15 cm. long, spatulate or oval, 

 or obovate, narrowed into winged petioles, the lower stem-leaves like the basal, passing 

 through oval to ovate, the upper ones sessile or nearly so : racemes sessile or very short- 

 peduncled : pedicels 1-2 cm. long, spreading or ascending : calyx campanulate ; lobes 



