LOBELIA FAMILY 223 



Anthers united; stem-leaves developed. 



Hypanthium cylindric or linear-clavate; pod at maturity 1-celled. 



Aquatic plants with two kinds of flowers, tlie submerged ones cleistogamous ; pod 



splitting on one side. 2. Howellia. 



Land plants of wet situations: flowers all alike; pod splitting lengthwise by 1-3 

 slits, but the valves remaining united at the ape.x. 3. Bolelia.. 



Hypanthium turbinate or oblong; pod 2-celled, 2-valved. 



Corolla with a closed tube. 4. Porterella. 



Corolla split to near the base on the upper side. .5. Lobella.. 



1. NEMACLADUS Nutt. l. N. ramoissimus. 



2. HOWELLIA A. Gray. l. h. aquatilis. 



3. BOLELIA Raf. 



Corolla scarcely exceeding the obtuse sepals; stamens shorter than the sepals. 



1. B. brachyantha. 

 Corolla and stamens much exceeding the acute sepals. 2. B. elegans. 



4. PORTERELLA Torr. 



Pedicels longer than the floral leaves. 1. P. carnosula. 



Pedicels shorter than the floral leaves. 2. P. eximia. 



5. LOBELIA (Plum.) L. Lobelia, Cardinal-flower. 



Corolla red. 



Leaves oblong-ovate to ovate-lanceolate. 1. L. cardinalis. 



Leaves narrowly lanceolate to Linear. 2. L. splendens. 



Corolla blue or whitish. 



Corolla 2-2.5 cm. long. 3. L. syphilitica. 



Corolla less than 1 cm. long. 

 Stem leafy. 



Stem-leaves spatulate or oblanceolate ; raceme many-flowered; plant puberu- 



lent. 4. L. hirtella. 



Stem-leaves linear or linear-oblanceolate ; racemes few-flowered; stem and 

 leaves glabrous. 5. L. strictiflora. 



Stem scapiform; leaves all in a basal rosette, usually submerged. 



6. L. Dortmanna. 



Family 132. DIPSACEAS. Teasel Family. 

 1. DIPSACUS L. Teasel. i. d. sylvestris. 



Family 133. AMBROSIACEAE. Ragweed Family. 



Staminate and pistillate flowers in the same heads, the latter few (rarely solitary or none) , 

 marginal. 

 Achenes turgid, obovoid or pear-shaped, raarginless. 



Involucres of 5 dilated-ovate, rigidly acuminate bracts; achenes with a large ter- 

 minal areola, surroimded by a disk. 1. Oxytenia. 

 Involucres not with dilated rigidly acuminate bracts; terminal areola minute. 

 Heads paniculate; coroUa of the pistillate flowers rudimentary or none. 



2. Cyclach.\ena. 

 Heads spicately or racemosely disposed; corolla of the pistillate flowers evi- 

 dent. ;j. ivA. 



Achenes flattened, wing-margined; involucres of 5 ovate or oblong herbaceous bracts 

 and within them 1-2 large scarious ones subtending the pistillate flowers. 



4. DiCORIA. 



Staminate and pistillate flowers in different heads, the latter I-l, without corolla and 

 enclosed in a nut-like or bur-like involucre. 

 Involucres of the staminate heads with united bracts; receptacles low; rudimentary 

 styles penicillate or fimbriate at the apex. 

 Involucres of the solitary pistillate flower with 9-12 dilated scarious wings; anther- 

 tips blunt. o Hymenoclea 

 Involucres of the 1-4-flowered pistillate heads not winged, but usuaUy armed with 

 spines or tubercles; anther setiferous-acuminate. 

 Spines or tubercles of the 1-flowered pistillate heads in a single row. 



0. Ambrosia. 

 Spines of the I-4-flowered pistillate heads in more than one row. 



7. Fr.^nseria. 

 Involucres of the staminate heads with distinct bracts; receptacle cyhndraceous; 

 spines of the 2-flowered pistillate heads in several rows, uncinate. 8. X'anthium. 



1. OXYTENIA Nutt. l. o. acerosa. 



2. CYCLACHAENA Fresen. Horseweed, Carele.ss Weed. 



1. C. xanthifolia. 



3. IVA L. Marsh Elder, Bozzleweed, Salt Sage, Poverty Weed. 



1. I. axillaris. 



