Variety of Nothia cross-sections in Rhynie chert
deutsche Version

What is known as Nothia now had been mistaken for small branches of Asteroxylon for decades.
(All the alleged Asteroxylon sporangia in Kidston's slide collection at the Hunterian Museum, Glasgow, very probably have to be re-interpreted, according to comparison with own samples, as Nothia sporangia.)
It is still confusing to see these branches, and small sporangia now assumed to belong to Nothia, more often than expected associated with Asteroxylon, and even immediately beside Asteroxylon cross-sections, while the very Asteroxylon sporangia tend to be elusive.
After recognition as a separate species as late as 1964 [1], Nothia was thoroughly described in 1979 [2] and 2001 [3]. Its cross-sections are usually not circular because of numerous mound-shaped emergences on the surface. (Note that any plant may appear with a rugged outline in the chert as a result of shrivelling by drying or fungus-induced shrinkage before silicification.)  

Arrangement and build of the sporangia suggest an affiliation with the zosterophylls. However, there seem to be reasons to refrain from such conclusion, among them the same questionable reason for which Aglaophyton had been widely separated from Rhynia, namely the absence of a tracheid wall pattern of the proper type.
Drawing of a Nothia cross-section with funny aspect
If among odd-shaped cross-sections there are some with the central strand once or twice divided and eventually looking like a funny face, one can be nearly sure it is Nothia. One of them is suitable as a logo for the issues of Rhynie Chert News.
Nothia sporangium with tubes
Sporangia with exceptionally well preserved structure suggest that the tubes along the epidermis called "giant cells" in [3] and thought to be "real cells" there, possibly are no such but early versions of the poison tubes by which many flowering plants protect themselves against herbivores. (See also Rhynie Chert News 57, Figs.5-7.)
Annotation: Cross-sections of shrivelled Horneophyton can be very similar to those of Nothia.

[1] A.G. Lyon: Nature 203 (1964), 1082-83.
[2] W.El-S. El-Saadawy, W.S. Lacey: Observations on Nothia aphylla,
      Rev. Palaeobot. Palyn. 27 (1979), 119-147.
[3] H. Kerp, H. Hass, V. Mosbrugger: New data on Nothia aphylla,
      in: P.G. Gensel, D. Edwards (eds.): Plants Invade the Land, N.Y. 2001.

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