AMMIACEAE 869 



1. Deringa Canadensis (L. ) Kuntze. Glabrous or nearly so. Stems 3-10 dm. tall, 

 finally widely branched : leaf-blades 3-foliolate ; leaflets ovate, oval or elliptic, 4-10 cm. 

 long, acute or abruptly pointed, doubly serrate with sharp teeth, the lateral ones often 

 lobed : umbels peduncled : rays few, slender, unequal in length : pedicels 2-25 mm. long : 

 corolla white, 2-3 mm. broad : fruit oblong, 4-6 mm. long, straight, or curved at full 

 maturity. [ Crypfotaenia Canadensis ( L. ) DC. ] 



In thickets and copses, New Brunswick to South Dakota, Georgia and Texas. Spring and summer. 



22. AMMI L. 



Herbs resembling Buxlcus in habit and inflorescence. Leaves alternate : blades finely 

 divided or dissected, the segments entire or toothed. Flowers perfect, very numerous in 

 compound umbels. Involucres and involucels present, the bracts of the involucre, at least, 

 divided. Hypanthium truncate. Petals white, very unequal, cleft at the apex. Stylo- 

 podium flat. Fruit short, laterally flattened : carpels 5-angled, with prominent ribs and 

 an oil tube in each interval. Seeds terete or half-terete. 



Ultimate segments of the leaf-blades toothed : mature umbel open. 1. A. majus. 



Ultimate segments of the leaf-blades entire : mature umbel contracted. 2. A. Visnaga. 



1. Ammi majus L. Stem 3-8 dm. tall, branched. Ultimate segments of the leaf- 

 blades toothed : mature umbels and umbellets open, the concreted bases of the rays of the 

 latter barely 2 mm. broad : fruit 1.5-2 mm. long. 



In waste places, southern Texas. Introduced from Europe. 



2. Amml Visnaga (L. ) Lam. Stem 5-12 dm. tall. Ultimate segments of the leaf- 

 blades entire : mature umbels and umbellets contracted, the concreted bases of the rays of 

 the latter 3-4 mm. broad : fruit 2-2.5 mm. long. 



In waste places, near Pensacola, Florida, and on ballast at other seaports. Introduced from Europe. 



« 



23. TAENIDIA Drude. 

 Perennial caulescent herbs, with glabrous or glaucous foliage. Leaves alternate : 

 blades pinnate or ternately compound : leaflets entire or toothed. Flowers in spreading 

 naked umbels. Hypanthium with a truncate or nearly truncate margin. Petals 5, their 

 tips inflexed. Stylopodium wanting. Styles slender. Fruit oblong, more or less strongly 

 laterally flattened : carpels 5-angled, with slender ribs and 3 oil-tubes in the intervals. 

 Seeds nearly terete except the flat face. Pimpernel. 



1. Taenidia integ^rrima ( L. ) Drude. Root stout, tough. Foliage glaucous : stems 

 sometimes branched at the base, 3-9 dm. tall, branching above : leaf-blades 5-20 cm. long : 

 twice or thrice ternately compound ; leaflets ovate to oblong or oblong-lanceolate, entire, 

 1-3 cm. long, apiculate : umbels long-peduncled ; rays 10-20, wire-like, 5-8 cm. long, un- 

 equal : pedicels 8-15 mm. long: corolla yellow, 1-1.5 mm. broad : fruit broadly oblong, 

 3.5-4 mm. long. 



On rocky hillsides and in sandy soil, Quebec to Minnesota, Georgia and Mississippi. Spring. 



24. EULOPHUS Nutt. 



Perennial caulescent herbs, with tuberous roots. Leaves alternate : blades ternately 

 compound. Flowers in compound umbels. Involucre wanting or of 1 bract. Involucels 

 usually of 2 bracts. Sepals prominent. Petals white or pink, broadest above the middle, 

 inflexed at the tip. Disk with a conic stylopodium. Fruit somewhat elongated, laterally 

 flattened : carpels delicately ribbed : oil-tubes 2-5 in the intervals. 



1. Eulophus Americanus Nutt. Foliage glabrous. Stems 8-15 dm. tall, branched 

 above, leaf-blades various, those of the basal and lower stem-leaves 1-4 dm. long, biter- 

 nately compound, with linear or oblong-linear leaf -segments, those of the upper stem-leaves 

 ternate, their leaf segments narrowly linear and elongated : umbels with 10-20 rays : bracts 

 of the involucres much reduced or none ; those of the involucels linear-lanceolate, 2 mm. 

 long : fruit oblong or oblong-ovoid, 4-6 mm. long, 3-4 mm. broad, the oil-tubes 3 between 

 the more or less obsolete ribs, 4 in the inner side. 



In low grounds, Ohio to Missouri, Tennessee and Arkansas. 



25. SIUM L. 



Perennial caulescent herbs of swamps or marshy places. Leaves alternate : blades 

 pinnately compound : leaflets toothed, pinnatifid or dissected. Flowers perfect, in com- 



