17U AMMIACEAE 



Plant 1-2 dm. high, glabrous; leaflets ovate or lanceolate, few-toothed, 5-15 mm. 

 long; fruit oblong, 6-7 mm. long. 4. O. MacDougali. 



21. HARBOURIA Coult. & Rose. l. //. trachypleura. 



22. SiUM (Tourn.) L. \Yater Parsnip. l. S. cicutaefoHum. 



23. CICIJTA L. Cow Bane. Poison or Water Hemlock. 

 Axils of the leaves not bearing bulblets; leaflets lanceolate. 



Bractlets scarious-margined. 1. C. cinicola. 



Bractlets not scarious. 



Fruit orbicular in outline; rootstock usually horizontal or ascending. 



2. C. vaoans. 

 Fruit oval in outUne; rootstock exceedingly short, erect. 3. C. occidentalis. 



Axils of the leaves (especially the upper ones) bearing bulblets; leaflets narrowly linear. 



4. C. butbifera. 



24. AULOSPERMUM Coult. & Rose. . 



Involucres present. 1, A. glaucum. 

 Involucres wanting. 

 Corolla yellow. 



Rachis of the primary leaf-segments dilated: secondary segments confluent. 



broad, toothed or merely cleft. 2. A. lonqipes. 



Rachis of the prmiary lea,f-segments not dilated; secondary segments distinct, 



finely dissected into oblong lobes. 3. A. angustum. 

 CoroUa not yellow. 



Corolla white. 4. A. ibapense. 



Corolla purple. 5. A. planosum. 



25. PHELLOPTERUS Nutt. 



Wings of the fruit tliin and broad, scarcely rugose. 



Pedvmcles even in fruit shorter than the leaves; wings thickened at the insertion. 



Flowers white; fruit 6—8 mm. long. 1. P. montanus. 



Flowers purple; fruit 10-14 mm. long. 2. P. macrocarpus. 



Peduncles at least in fruit equalling or exceeding the leaves; wings not thickened at 

 the insertion; fruit more than 8 mm. long. 

 Involucels 1-3-nerved; corolla piu-plish. 



Fruit oblong. 3. P. biilbosus. 



Fruit orbicular. 4. P. utahensis. 

 Involucels 5-13-nerved. 



Bracts wliite with green middle; coroUa white or pink. 5. P. camporum. 



Bracts and corolla purple. 6. P. vutUinervatus. 



Wings of the fruit thick, somewhat corky and rugose. 7. P. Jonesii. 



26. CORIOPHYLLUS (^I. E. Jones) Rydb. Indian Parsnip. 



Wings thickened at the insertion. 



Leaves ternately bipinnatifld; oil-tubes soUtary in each interval. 1. C. Jonesii. 



Leaves pinnate, with lobed or divided leaflets; oil-tubes several in each interval. 



Leaves ovate to ovate-oblong in outline; flowers pedicelled. 2. C. Rosei. 



Leaves reniform to oblong-cordate in outline; flowers sessile. 3. C. basallicus. 

 Wings not thickened at the insertion. 



Flowers purplish; oil-tubes on the commissure 8. 4. C. ptirpureus 



Flowers greenish yellow; oil-tubes on the commissure 4. 5. C. Betheli. 



27. PTERYXIA Xutt. 

 Petals yellow. 



Leaves broadly rhombic in outline. 



Dorsal ribs with broad wings. 1. P. foeniculacea. 



Dorsal ribs with narrow wings. 2. P. Elrodi. 

 Leave-s oblong or ovate in outUiie. 



Pinnae very small and distant. 3. P. petraea. 



Pinnae larger and crowded. 4. P. calcarea. 



Petals wliite. 5. P. albi flora. 



28. PSEUDOREOXIS Rydb. l. P. bipinnaius. 



29. CYMOPTERUS Raf. 



Umbels dense, globular; petals white; involucre wanting. 

 Involucels of linear to oblong bractlets. 



Ultimate divisions of the leaves Imear or linear-oblong, acutish; fruit orbicular, 



6-8 mm. long. 1. C. acaulis. 



Ultimate divisions of the leaves short, broadly oblong, obtuse; fruit 7-10 mm. long. 

 Bractlets oblong, rarely lanceolate, obtuse; fruit orbicular, 8-10 mm. broad; 



wings strongly thickened. 2. C. Parryi. 



Bractlets linear or lanceolate, acute; fruit oval, 6-8 mm. broad; wings moder- 

 ately tliickened. 3. C. lucidus. 

 Involucels of broad membranous, more or less 3-cleft bractlets; fruit fully 10 mm. 

 long, broadly elliptic. 4. C. Leibcrgii. 



