Like other Early Devonian plants, the sporophyte of
Adoketophyton consisted of leafless stems (axes), approximately 1 to 2.5 mm in diameter. These branched equally or unequally (pseudomonopodially). Its
vascular tissue was relatively simple, consisting of a central (
centrarch) cylinder of primary
xylem with G-type
tracheids. Fossils suggest that stems which did not bear
sporangia initially had coiled (circinnate) tips, consistent with other "
zosterophylls", and similar to the way in which modern
ferns grow. A unique feature of this genus among plants of similar age is the manner in which the sporangia (spore-forming organs) were borne. Fertile stems had terminal '
strobili', structures very superficially resembling an ear of
wheat, which consisted of four vertical rows of fan-shaped leaf-like organs (sporophylls), each with a stalked sporangium on the side facing the stem (adaxial). The flattened sporangia were almost round and split (dehisced) along a distally thickened margin into two equal parts. The sporophylls may have had vascular tissue. A second species,
A. parvulum, was described in 2011. The species differ in size overall; for example, the largest strobili found were 90 mm long in
A. subverticillatum, but only 17 mm long in
A. parvulum. The relative size of the sporophylls and the sporangia is also different: they were roughly the same height in
A. parvulum, whereas the sporangia were a half to a third of the height of the sporophylls in
A. subverticillatum. ==Phylogeny==