AGAVES OF THE UNITED STATES. 91 
and disposed them in layers like the fibers of the Egyptian 
papyrus and the mulberry ( Broussonetia) of the South Sea 
Islands. This formed paper upon which their hieroglyphics 
were painted. Their manuscripts were folded in rhombic 
form and were bound in some resemblance to our quarto 
books by fastening wooden boards to the extremities. 
Humboldt states that no nation of the old continent made 
such an extensive use of hieroglyphics and in none do we see 
real books bound in the way described. 
+-++ Leaf without horny margin, slightly if at all repand; teeth small 
if present.— RiGiIpaE (Baker). 
++ Somewhat caulescent; leaves usually entire. 
A RIGIDA SISALANA Engelm.— Leaves bright dark green, 
120 to 180 cm. long, 10 to 14 cm. wide, narrowed, thick- 
ened and keeled above the base, broadest a little above or 
at the middle, and tapering to the apex; terminal spine 
terete, reddish-brown, not channeled, but slightly indented 
at the base, 1 to 2 cm. long, not decurrent ; margin usually 
entire, but often with occasional sharp, unequal prickles, 
and sometimes with stout ones; scape 45 to 90 dm. high; 
panicle much branched, sometimes covering half the length 
of the scape, and having a width about half its length; 
flowers 55 to 65 mm. long; ovary rather broad; perianth 
campanulate, 33 to 35 mm. long; segments a little longer 
than the tube; filaments inserted above the middle, nearly 
at the line which would mark the upper third of tube, 55 to 
60 mm. long; anthers 2 cm. long; capsules oblong, about 
50 mm. long and half as wide. Propagation by pole plants . 
and suckers.— Trans. St. Louis Acad. iii. 312, Collected 
Writings, 312; Baker, Amaryllideae, 181.— Yucatan, 
Southern Florida below the frost line, and the adjacent 
islands, including the Keys and the Bahamas.— Plates 54, 
55 and 56. Dr. Havard and Dr. Coulter state that it 
occurs in Southern Texas. 
Specimens examined: —From Merida, Yucatan, Dr. 
Schott, 1865; Key West, Wright, Parry, and Brummel, 
