274 American Midland Naturalist Monograph No. 7 



71. Pyrrhopappus DC. — False Dandelion 

 P. carolinianus (Walt.) DC. Dry soil in s. 111., extending northward 

 to Hancock, Sangamon, and Crawford counties. May-June. 



72. Agoseris Raf. 



A. cuspidata (Pursh) D.Dietr. Dry soil, rare, in the northern 



half of the state, southward to Tazewell and Champaign counties. 



May-June. 



73. Taraxacum Zinn — Dandelion 



1 . Achenes greenish-brown; heads usually 3-5 cm in diameter, 150- 

 to 200-flowered, the flowers orange-yellow; outer involucral 

 bracts reflexed; leaves usually sinuate to coarsely pinnatifid, 

 the terminal lobe large; waste places, fields, roadsides, lawns, 

 etc., very common; nat. from Eur. Mar. -Nov. Common 



Dandelion [Leontodon taraxacum L.; L. vulgaris Lam.] 



- T. officinale Wiggers 



1. Achenes red or reddish-brown; heads 2-3 cm in diameter, 75- to 

 125-flowered, the flowers sulphur-yellow; leaves deeply pin- 

 natifid, the terminal lobe small; waste places, less frequent 

 than the preceding; nat. from Eur. Apr. -June. Red-seeded 

 Dandelion [T. laevigatum of auth., not (Willd.) DC; Leon- 

 todon crytlirospermum (Andrz.) Eichw.] 



- T. crythrospermum Andrz. 



Class II. Monocotyledoneae (Juss.) DC. 



126. Alismaceae DC. — Water-plantain Family 



1. Flowers numerous, small, perfect, in a compound panicle; leaves oval or 

 ovate; stamens usually 6; carpels flattened, arranged in a ring on a small 



flat receptacle 1. Alistna 



1. Flowers in whorls, fewer; stamens 9-many; carpels in a head on a convex 

 receptacle. 

 2. Leaves cordate or ovate, with 5-7 veins from the base; flowers perfect, 



3-9 or more in each whorl: plants annual 2. Echinodorus 



2. Leaves sagittate or lanceolate, more than 7-veined; plants perennial 



3. Sngittaria 



1 . Alisma L. — Water-plantain 



1. Petals 1-2 mm long; achenes 1.5-2 mm long; ditches and margins 

 of ponds, common. July-Sept. [A. plantago-aquatica Am. 

 auth., non L.] A. subcordatiirn Raf. 



1. Petals 3-5 mm long; achenes 2.2-3 min long; in similar habitats, 

 but apparently less common. [A. plantago var. americanurn 

 R. & S. : A. hrevipes Greene] A. trivialc Piu'sh 



2. Echinodorus Rich. — Burhead 



1. Leaves linear-lanceolate; scape 3-10 cm tall; stamens 9; achenes 

 10-15, black, merely apiculate; muddy shores, rare; Cass, 



Mason, and St. Clair counties. [E. tenellus (Mart.) Buch.] 



E. parvulus Engelm. 



