AMMIACEAE 865 



1. Torilis nodosa (L.) Gaertn. Foliage hispid. Stems usually branched from the 

 base, the branches ascending, spreading or decumbent, 1-4 dm. long, often zigzag : leaf- 

 blades once or twice pinnate, 2-6 cm. long ; segments pinnatifid : umbels sessile or short- 

 peduncled, forming clusters opposite the leaf-bases : bracts narrow : rays 1-3, very short : 

 fruit ovoid or oblong-ovoid, about 3 mm. long, the outer armed with barbed spines, the inner 

 sharply tuberculate. 



In waste places, Pennsylvania to Iowa, California, Florida, Texas and Central America. Natural- 

 ized from Europe and Africa. Spring to summer. 



9. CORIANDRUM L. 



Annual slender caulescent herbs. Leaves alternate : blades pinnately dissected. Flow- 

 ers perfect, in compound umbels. Involucres wanting. Sepals acute, unequal. Petals 

 white, often unequal, broadest above the middle, inflexed at the apex. Disk with a conic 

 stylopodium. Fruit subglobose, not constricted at the commissure : carpels with 5 delicate 

 ribs : oil-tubes solitary under the secondary ribs. CORIANDER. 



1. Coriandrum sativum L. Foliage glabrous. Stems erect or ascending, 2-6 dm. 

 tall, branched: leaf-blades various, dissected, those of the lower cauline and basal leaves with 

 coarse-toothed incised or lobed segments, those of the upper leaves with narrowly linear seg- 

 ments : umbels peduncled, 1.8-5 cm. broad: rays 4-8, spreading or ascending, 1-2 mm; 

 long : pedicels 1-3 mm. long : corolla white : fruit subglobose or ovoid-globose, 3-3.5 

 mm. long, slightly ribbed. 



In waste places, in and about most of the larger cities of the United States. Naturalized from the 

 Mediterranean region. Summer. 



10. BIFORA Hoffm. 



Annual caulescent herbs, with glabrous foliage. Leaves alternate : blades pinnately 

 dissected. Flowers perfect, in compound umbels. Involucres and involucels of few' 

 bracts or wanting. Hypanthium truncate, or sepals very small. Petals white, broadest 

 above the middle, inflexed at the tip. Disk with a small conic stylopodium. Fruit 

 broader than long, laterally flattened : carpels without primary ribs and with 4 secondary 

 ribs : oil-tubes wanting. 



1. Bifora Americana ( DC. ) S. Wats. Foliage more or less scabrous. Stems 2-6 

 dm. tall, corymbosely branching above : leaf -blades 2-6 cm. long, the segments narrowly 

 linear or linear-filiform : umbels 1.5-5 cm. broad : bracts linear-subulate, or pinnatifid : 

 rays 5-8, nearly equal, 10-20 mm. long : pedicels 2-3 mm. long : corolla white, 3-3.5 

 mm. broad : fruit 4-5 mm. broad, faintly ridged, each carpel subglobose. 



In dry soil, Arkansas and the Indian Territory to Texas. Spring and summer. 



11. AFIASTRTTM Nutt. 



Annual, usually slender caulescent herbs, with glabrous foliage. Leaves alternate : 

 blades finely dissected. Flowers in naked or nearly naked compound umbels. Involu- 

 cels rarely present. Hypanthium truncate or nearly so. Sepals obsolete. Petals white, 

 entire, flat or inflexed at the apex. Disk with a small stylopodium. Styles short. Fruit 

 longer than broad, laterally flattened : carpels tuberculate, not ribbed : oil-tubes solitary 

 in the intervals and under the secondary ribs, and 2 in the inner side. 



1. Apiastrum patens (Nutt. ) Coult. & Rose. Stems 2-6 dm. tall, branched above, the 

 branches slender, more or less spreading : leaf -blades 2-5 cm. long, once or twice ter- 

 nately parted, the segments filiform : umbels long-peduncled : rays very variable in length, 

 1-15 mm. long, erect or ascending : corolla white, minute : fruit ovoid, stout, 1 mm. long, 

 granular. . 



On prairies and plains, Indiana to Nebraska, Texas and New Mexico. Spring and summer. 



12. ERIGENIA Nutt. 



Low perennial caulescent herbs, with tuberous roots. Leaves alternate : blades ter- 

 nately decompound. Flowers in few-rayed compound umbels. Involucres usually of a 

 single bract. Hypanthium truncate. Petals white, broadest above the middle, flat. 

 Fruit broader than high, laterally flattened : carpels with 5 delicate ribs : oil-tubes 2-3 in 

 each interval. 

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