44 



ASTERACEAE 



Sonchus — Sow-thistle 



(Gr. name of the sow-thistle) 



1. Perennial; heads 2-3 cm. wide 5. arvensis 



2. Annual 



a. Achenes wrinkled crosswise ; ears of leaves acute 5. olerdceus 



b. Achenes 3-striate on each side ; ears rounded S. dsper 



Lactuca — Lettuce 



(Lat. lactuca, lettuce, from lac. milk, referring to the miiky juice) 



1. Pappus white 



a. Flowers blue £. pulchella 



b. Flowers yellow or cream-colored 



(1) Cultivated L. saliva 



(2) Native 



(a) Leaves' twistej into a vertical position, midrib spiny L. scariosa 



(b) Leaves normal, pinnatifid ; margin spiny L. ludovicidna 



2. Pappus brown L. spicdta 



Hieracium — Hawk weed 



(Gr. hieracium, hawkweed, from hierax, hawk) 



1. Leaves and stem with hairs 2-3 cm. long; achene long-beaked //. longipilum 



2. Leaves and stem with short stout hairs; achenes truncate //. scabrum 



Crepis — Hawksbeard 



(Gr. krepis, boot, base, perhaps from the 

 Leaves lanceolate, pinnatifid ; heads yellow 



basal 



1. Pappus dark brown 



2. Pappus straw-color 



a. Involucre hair} - 



b. Involucre smooth 



Leaves lobed ; heads blue 



Xabalus — Xabalus 



(Latinized form of the Indian name) 



Cichorium — Chicory 



(Latinized form of the Arabic name) 



Monocotyledons 



rosette) 



C. tcctdrum 



bus 



X. dsper 



X. altissimus 



C. intybus 



Alismales Arrowhead Order 



Alismaceae — Arrow-head Family 

 Aquatic and marsh herbs, with fibrous roots, flowers in clusters ; sepals 3, not petal-like, petals 3, 

 stamens 6-many, pistils several-many ; flowers apocarpous, apopetalous, hypogynous, regular. 



1. Each pistil 1-seeded 



a. Flowers perfect; pistils in a ring Alisma 



b. Pistillate and staminate flowers separate ; pistils covering a convex 



receptacle Sagittaria 



2. Each pistil many-seeded 



a. Stamens 9, fertile Butomus 



b. Numerous fertile and sterile stamens Hydrocleis 



Alisma — Water-plantain 



(Gr. alisrra, a water plant) 

 Native plant with ovate leaves, and many small flowers in an upright panicle A. plantago-aqudtica 



Sagittaria — Arrow-head 



(Lat. sagitta. arrow, from the shape of the leaves) 

 Several species, mostly blooming in midsummer 



1. Leaves arrow-shaped; pistillate flowers obviously stalked S. latxjolia 



2. Leaves linear, ovate, or rarely arrow-shaped ; pistillate flowers not 



stalked 5. rigida 



