AMMIACEAE 871 



28. CYNOSCIADIUM DC. 



Annual caulescent herbs. Leaves alternate : blades pinnately or palmately divided 

 into narrow segments, or the basal leaves with entire blades : flowers perfect, in compound 

 umbels. Involucres and involucels of persistent or deciduous narrow bracts. Sepals per- 

 sistent. Petals broadest above the middle, inflexed at the apex. Disk with a conic stylo- 

 podium. Fruit elongated, dorsally flattened : carpels with strong ribs, the lateral ribs 

 more prominent : oil-tubes solitary in each interval or two in the inner face. 



Leaf-segments palmately disposed : fruit with an oval or globose body and a long beak. I. C. digitatum. 

 Leaf-segments pinnately disposed : fruit with an oblong body and no beak. 



Stems simple at the base : fruit fully 3 mm. long. 2. C. pinnatum. 



Stems branched at the base : fruit about 2 mm. long. 3. C. pumilum. 



1. Cynoaciadium digitatum DC. Stems erect or ascending, 2-6 dm. tall, branching 

 above: leaf-blades various; those of the basal leaves linear or linear-lanceolate, entire, those 

 of the stem-leaves palmately 3-5-parted ; segments linear or nearly so, each narrowed to a 

 slender tip : umbels peduncled, rather irregular : rays usually 3-8, 2-3 mm. long : pedicels 

 unequal, 6-20 mm. long : fruit 3 mm. long, the body oval or subglobose, longer than the 

 beak, prominently ribbed. 



In wet grounds, Arkansas to Alabama and Texas. Spring and summer. 



2. Cyaosciadium pinnatum DC. Stems erect or decumbent, 1-5 dm. tall, sparingly 

 branched : leaf-blades various ; those of the basal leaves entire, 3-8 cm. long, longer than 

 those of the stem, or like those of the stem pinnately divided ; segments few, linear, atten- 

 uate, the terminal one larger: umbels many-flowered, 2-5 cm. broad : rays 5-10, often uni^ 

 form in length, 1-2.5 cm. long : pedicels 2-8 mm. long, very slender : fruit oblong, 3 mm. 

 long, not beaked, less prominently ribbed than in C. digitatum. 



In wet grounds, Missouri to Arkansas and Texas. Spring and summer. 



3. Cynosciadium pumilum (Engelm. & Gray) Coult. & Kose. Stems low and 

 diffusely branched : leaf-blades similar to those of C. pinnatum : umbels with 3-6 rays : sepals 

 larger than in C. pinnatum: fruit oval to suborbicular, about 2 mm. long, terminating in 

 the small stylopodium. 



On prairies, southern Texas. Spring. 



29. LILAEOFSIS Greene. 



Low succulent herbs of marshy situations, with creeping stems. Leaves clustered at 

 the nodes, reduced to terete club-shaped septate organs, sometimes dilated above. Bracts 

 of the involucre several. Flowers perfect, several in simple peduncled umbels. Sepals 

 acute. Petals white, concave, somewhat hooded at the apex. Fruit subglobose, or lentic- 

 ular, laterally flattened : carpels with thick, corky lateral ribs and filiform dorsal and inter- 

 mediate ribs or all sometimes corky, with oil-tubes solitary in the intervals. Seeds terete. 

 [Crantzia Nutt.] 



Peduncles surpassing the leaves : fruit pinched at the base ; lateral ribs only corky. 1. L. lineata. 

 Peduncles shorter than the leaves : fruit not pinched at the base ; all ribs corky. 2. L. Carolinensis. 



1. Lilaeopsis lineata (Michx.) Greene. Stems creeping in the mud. Leaves 2-5 

 cm. long ; petioles dilated upward, usually linear-spatulate, barely broadened into blades, 

 conspicuously cross-partitioned : peduncles 3-7 cm. long, surpassing the leaves : fruit or- 

 bicular-ovoid, pinched near the base, about 2 mm. long, the lateral ribs corky, the dorsal 

 not at all corky. [ Crantzia lineata Nutt. ] 



In salt and brackish marshes and low grounds, Massachusetts to Florida and Mississippi. Summer. 



2. Lilaeopsis Caroline" nsis Coult. & Rose. Stems creeping in the mud. Leaves 

 5-25 cm. long ; petioles elongated ; blades oblong or spatulate : shorter than the petioles : 

 peduncles 1-1.5 cm. shorter than the leaves : fruit suborbicular or oval-orbicular, about 

 3 mm. long, not pinched near the base ; all the ribs corky. 



In low grounds, eastern North Carolina and Louisiana. Summer. 



30. EURYTAENIA T. & G. 



Herbs, with slender branching stems and glabrous foliage. Leaves alternate : blades 

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

 cleft bracts. Sepals prominent, thin. Corolla white. Disk with a depressed stylopo- 

 dium. Fruit usually flattened : carpels with slender dorsal and contiguous ribs and lateral 

 wings : oil-tubes solitary in the intervals. 



