746 BOTANY AND PHARMACOGNOSY. 



/8 Sclerenchymatoiis Tissue Wanting. 

 I. Pollen Grains Numerous, 



81. ARNICA FLORES. Yellowish-brown; pollen grains 

 spherical, with numerous centrifugal projections, 3-pored, 25 to 35 

 fjL in diameter; non-glandular hairs of three kinds either uni- 

 cellular, 5- or 6-celled or consisting of a pair of united unicellular 

 hairs with numerous pores on the dividing wall ; glandular hairs 

 of three kinds either with a large unicellular stalk and unicellular 

 glandular head, or with a stalk of a single row of 4 cells and a 

 i-celled glandular head, or a stalk of a double row of 5 cells and 

 a 2-celled glandular head ; pappus consisting of a multicellular 

 axis with unicellular branches (Figs. 119, B; 241). 



82. SAMBUCUS. Starch grains not present; pollen grains 

 numerous, spherical or elliptical and nearly smooth, about 18 /x 

 in diameter ; numerous fragments composed of broken or whole 

 anthers ; corolla with dentate papillae ; oil globules from secretion 

 cells ; in calyx some rosette aggregates of calcium oxalate ; in 

 flower stalk, large spiral duct 30 /x wide, and parenchyma with 

 brown contents. 



83. MATRICARIA. Pollen grains numerous, nearly spher- 

 ical or triangular, very spinose, from 18 to 25 fi in diameter; 

 fragments of corolla with glandular hairs ; characteristic cells of 

 anther ; stigma with papillae ; peculiar ladder-like cells of wall 

 of akene ; sclerenchyma fibers of involucral scales. 



2. Pollen Grains Few. 



84. CALENDULA. Bright yellow (Fig. 296, B) ; charac- 

 teristic tissue of petals containing oily drops ; few pollen grains ; 

 colored brownish with sulphuric acid. 



85. CROCUS. Orange-red (Fig. 296, A) ; glycerin mount 

 of deep orange color ; few, nearly smooth, nearly spherical pollen 

 grains, 85 to 100 /x in diameter ; papillae of stigma ; coloring prin- 

 ciple soluble in water but not in fatty oils, being the reverse in 

 capsicum ; with sulphuric acid fragments become blue immediately. 



86. ANTHEMIS. Non-glandular and glandular hairs; 

 spherical, prickly pollen grains about 30 /x in diameter, which are 



