EAELY PENNSYLVANIA FLORA FROM WEST-CENTRAL ILLINOIS 



length-to-width ratio is about 2:1; the cushions are 1.3 to 1.5 cm long 

 and 0.5 to 0.7 cm "wide. Each cushion merges with those above and below. 

 There are transverse wrinkles on the lover portion of nearly all 

 the cushions, and wrinkles are visible on the upper part of one. A 

 prominent ligule scar, a short vertical slit, is seen just above the 

 leaf scar. The outlines and details of the leaf scars are not clear. 

 They are located just above the center of the cushions and appear to be 

 nearly as wide as the cushions. 



SPHENOPSIDS 

 Annular i a cf. ve mens is 

 Text fig. 1+B, C; pi. 1, fig. h 



Description . — The leaves, averaging 12 in a verticil, are 5 mm 

 long and 1 mm wide. Each leaf is slightly longer than the internode. 

 The leaves are conspicuously lanceolate, more or less uniform in width, 

 taper toward the base and toward the acute apex. They are equal in 

 length, radiate from the node; they are straight or slightly curved. The 

 midrib is 0.3 mm wide and is longitudinally striated. The stem is 1 mm 

 wide, with inter nodes 3 to k mm long. 



Discussion . — A single specimen referable to this species has 

 been found at Spencer Farm. At first glance, the leaf arrangement ap- 

 pears to be that of Asterophyllites , an impression held originally by 

 Arnold (19^+9) regarding his specimen from Michigan. However, closer 

 examination of the Illinois specimen reveals that some leaves radiate 

 from the axis at an angle greater than 90°. Abbott (1958) interpreted 

 the leaves as radiating from the node in a single plane and transferred 

 this species to Annularia. 



The number of leaves per whorl is not determinable from the Il- 

 linois specimens. A maximum of six is observed although it is certain 

 that others were originally present but are not visibly preserved. The 

 ratio of width to length of the leaves is more like that of Annularia 

 than Asterophyllites , as originially noted by Arnold (19^9, p. 183) and 



Abbott (1958, p. 326) 



Annularia cf. aster is 



PI. 1, fig. 6 



One specimen of Annularia has been found in the Spencer Farm 

 Flora; it shows only a single whorl of leaves. The leaves are 3 to k mm 

 long and about 1 mm wide. The midvein is not visible. There are eight 

 leaves in the whorl, which is 7 mm in diameter. 



The specimen is similar to A. asteris in the number of leaves in 

 the whorl, in overall size, and in the general shape of the leaves. 



Asterophyllites longifolius (Sternberg) Brongniart 

 PI. 1, fig. 5 



The linear leaves are 1.5 mm wide, except for a single specimen 

 (ISM kl6l2k) that has leaves only 0.25 to 0.375 mm wide; and they are 



