REVISION OF THE ENGLISH WEALDEN FLORA 



71 



Fig. 33 Reconstructions of Sidcatocladus robustus bearing leaves of Pseiidotorellia liiikii ( Romer) O Joan Watson & Nicola A. Harrison. 1 998. A, shoot 

 bearing elliptical leaves, the possible juvenile foliage; B, shoot bearing needle leaves, the possible adult foliage; both approximtely x 2.5. 



have become woody, as in living conifers. However, woody stems 

 have not been recognised in 5'. robustus which, like P. linkii. so far 

 occurs only as cuticular and resinous remains. We thus know nothing 

 of the older, thicker shoots of this species. 



Comparison. The two English species of Sukatocladus are dis- 

 cussed below in relation to similar unnamed Mesozoic shoots and 

 their associated leaves. 



Sulcatocladus dibbleri sp. nov. Fig. 34 



[Attributed to Sciadopityoides greeboami sp. nov. described above.] 



Diagnosis. Shoots 1-2 mm wide. Decurrent leaf bases 0.3-1.0 

 mm wide x 4.0-5.0 mm long. Foliage leaf scars triangular, occurring 

 at junction of 3 decurrent leaf bases. Cuticle of decurrent leaf bases 

 about 10 |am thick. Ordinary epidermal cells arranged in longitudinal 

 rows; rectangular or square, generally 20-1 15 pm long (rarely up to 

 200 jam long) x 10-30 pm wide; square cells more common near 



foliage leaf scar. Longitudinal ridges present over files of cells. 

 Papillae and trichomes absent. Hypodermis absent. Stomata longitu- 

 dinally orientated, restricted to zones adjacent to sutures, density up 

 to 1 5 per mm-. Stomatal pit spindle-shaped, rim smooth; flanked on 

 each side by one or rarely two subsidiary cells with domed or 

 thickened surface walls; single undifferentiated subsidiary cell may 

 or may not be present at each pole. Encircling ceils frequently 

 present. Guard cell pair slightly sunken; dorsal plates thickly cuti- 

 nized. isodiametric, 25-35 pm across; polar appendages usually 

 present; ventral walls frequently cutinized next to aperture. 



Name. After C.M.O.T. Dibbler, sausage-in-a-bun purveyor of 

 Ankh-Morpork in the Discworld novels of Teny Pratchett. 



Hoi.OTYPE AND TYPE LOCALITY. V.64593, Fig. 34D-G, a shoot 

 collected by Oldham at Galley Hill, East .Sussex. Ashdown Beds 

 Formation. Beixiasian. 



MATERIAL AND OCCURRENCE. Sukatocludus dihhicri sp. nov. has 



