236 PARSLEY ORDER 



Sium Linne 1753 



(The Greek name of a marsh plant) 



PI. 35, fig. 18. 



Sepals 5, united and grown to the ovary, teeth tiny, petals 5, white, 

 stamens 5, ovary 2-celled, stylopodium low, fruit flattened laterally, ovate 

 to oblong, each carpel with prominent nearly equal ribs, oil-tubes 1-3 in 

 the intervals, 2-6 on the commissure side ; leaves pinnate ; stemmed aquatic 

 or marsh perennial. 



Stems 2-6 ft. high ; leaflets 3-8 pairs, linear to lanceo- 

 late, toothed ; fruit 3 mm. long S. cicutifolium 



Thaspium Nuttall 1818 

 (Gr. thapsia, plant with a yellow dye) 



Sepals 5, united and grown to the ovary, teeth evident, petals 5, yel- 

 low, stamens 5, ovary 2-celled, stylopodium none, fruit ovoid, each carpel 

 with all the ribs strongly winged, oil-tubes solitary ia the intervals, 2 on 

 the commissure side ; leaves ternate ; tall stemmed perennial. 

 Stems 2-5 ft. high ; basal leaves mostly heart-shaped, 

 stem-leaves once-ternate ; fruits globose-ovoid, 4-5 

 mm. long T. trifolidhtw 



Washingtonia Rafinesque 1818 



(Named for George Washington) 



PL 35, fig. 10. 



Sepals 5, united and grown to the ovary, teeth none, petals 5, white or 

 purple, stamens 5, ovary 2-celled, stylopodium conic, fruit more or less club- 

 shaped, usually tapering to the base, and hairy; leaves 2-3-ternate ; stemmed 

 perennial. 



1. Fruits bristly-hairy 



a. Involucel present; style and base '2 mm. long; 



fruits 12 mm. long IV. longistylis 



b. Involucel wanting as a rule ; style and base" 



less than 1 mm. long; fruits 15-20 mm. long W. obtusa 



2. Fruits smooth; style and base 1-2 mm. long; 



fruits 12-16 mm. long W. occidentdlis 



Ztzia Koch 1825 

 (Named for Ziz, a German botanist) 



Sepals 5, united and grown to the ovary, teeth prominent, petals 5, yel- 

 low, stamens 5, ovary 2-celled, stylopodium none, fruit ovoid to oblong, 



