126 THE FLOKA OF NEBRASKA. 



Cliara r4>ittrafia A. Br. Schweiiier Char. )5. 1817, Nordst Praam. 111. 1882. 



Plauts rather long, 20-10 cm., not greatly branched; branches usually short; 

 stems and branches corticated; cortex-cells twice as many as the leaves 

 in the whorl ne.xt above; primary (or spine-bearing cortex cells) usually 

 most prominent; stipular whorl double; stipules ultimately falling off, 

 leaving two rows of scars; leaves G-10 in a whorl, variable in length and 

 number of corticated nodes, lower node always corticated; end-cell of 

 the leaf not corticated, short and obtuse; whorls often remote; monoe- 

 cious, 1-4 fertile joints; antherids small, 300-324 ji in diam, (280-350 fi 

 Migula); carpogones large, 900 // long; crown short and blunt; spore 

 570-012x370-380//; dark brown; 10-14 striate; bracts usually shorter than 

 the carpogone. 



Fremont, ponds in Cherry county; Ponca river, Boyd county. 



May be distinguished from C. ioetida by the larger spore. According to Mi- 

 gula the spores of C. foetida are never longer than 550 /x and those of 

 C. contraria never shorter than 550 /;. 



PI. XXXI., Fig. 1, part of a plant natural size; Fig. 2, part of stem showing 

 cortication, leaf-whorl, and stipular whorl x.jO; Fig. 3, part of leaf show- 

 ing naked end-cells and two fertile corticated nodes x50; Fig. 4, cross 

 section of stem .\50, (a) young spine. 



I'liara foetida A. Br. Ann. Sci. Nat. Bot. 1,11., .354. 1834. Flora 1835, p. G3. 



General habit like C. contraria, but more branched and leaf whorls-less re- 

 mote; stems and branches corticated; cortex-cells twice as many as the 

 leaves in the whorl next above; primary (or spine-bearing cells) usually 

 less prominent than secoudary cells; stipular-whorl double and promi- 

 nent; stipules persistent for some time and not blunt as in C. contraria; 

 leaves 6-10 in a whorl, with 1 to several corticated nodes, and 1 or more 

 naked ones;- end-cell of the leaf acute (not blunt as in C. contraria); 

 monoecious; 1-4 fertile joints; antherids about 3G0/J in diam.; carpogones 

 small; crown short, blunt; spores 486-,540x370-330 «; dark brown; 10-14 

 striate; 2 bracts at fertile joints longer than the carpogone, and i the 

 same length or shorter. 



Variations in the length of the bracts and the development of spines give 

 several forms: 



Form suBiNERMis LONGiBRACTE.\TA A. Br.— Spiues Very short or not developed, 

 bracts very long, 2-4 times the length of the carpogone. 

 Pumpkiuseed creek, Cheyenne county; Kimball; Cherry county; Ponca 

 river, Boyd county. 



Form SUBHISPIDA MiOROPTiLA ET BRACHTTELES A. Br.— Spines developed; bracts 

 shorter than the carpogone; end segment of leaf .short. 

 Buffalo creek, Haigler. 



Form SL-BiiispiDA macroptila et macroteles. a. Br.— Bracts longer than the 

 fruit; end-segment of leaf long. 

 Cherry county. 



PI. XXXII., Fig. 1, plant natural size; Fig. 2, part of stem showing one entire 

 leaf and the bases of the other leaves of a whorl (the leaf bent in order 

 to get it on the plate), (a), stipules, (&), spines; Figs. 3-4, cross sections of 

 stem, 3 a, spine coming from primary cortex cell x50. 



