The admedial is a vein that originates just beneath the tooth and
within a tooth framed by the principal, admedial, and conjunctal veins.
vein is an admedial vein, as well as conjunctals and sometimes
prorepens the admedial and principal veins are of the same order.
admedial and accessory veins converge and give rise to conjunctals (Fig.
Goniocrinus with a medium cone-shaped aboral cup; stellate ridges on aboral cup plates; low infrabasals; deep, peneplenary radial facets; two, high primibrachials; high secundibrachials; much expansion along the distal margin of brachials; ramulate arms with admedial
ramule every second brachial; and a recurred anal sac with multiple vertical ridges formed by plate sculpturing; column pentagonal; cirri in middle part of column.
From this stock the subgenus Gunnera evolved unicellular trichomes, reniform leaves with bases becoming lobate, a "trichotomous" midvein, moderate-sized primaries, reticulate orthogonal tertiaries, teeth with admedial veins of a lower order than the principal vein, and secondaries originating at increasingly obtuse angles apically.
Quaternary course: (0) orthogonal; (1) random reticulate; (2) ramified admedial; (3) fourth order lacking.
Suite of veins associated with the principal vein of the tooth: (0) no admedial, conjunctals and accessories only; (1) admedial and conjunctals only; (2) admedial, conjunctals, and one order of reticulate accessories; (3) admedial, conjunctals, and reticulate accessories in more than one order; (4) admedial, conjunctals, and freely ending accessories; (5) admedial and freely ending accessories, true conjunctals lacking; (6) Disanthus N/A; (7) Cnestis N/A.
Conjunctal veins: (0) joining and fusing with the principal vein, opposite; (1) joining and fusing with the principal vein, alternate; (2) incipiently connivent, with only a few strands merging; (3) connivent with the principal (i.e., running alongside it and splaying or ending concurrently in tooth epithem); (4) convergent but remaining separate; (5) only one conjunctal, joining; (6) "vitioid" tooth venation, in which alternate conjunctals split just before meeting the principal vein, with the admedial portion of the conjunctal joining the principal while the exmedial portion connives; (7) Cnestis N/A; (8) Disanthus N/A; (9) Griselinia N/A.
Strength of the admedial: (0) same order as the principal vein; (1) lower order than the principal vein; (2) N/A Disanthus; (3) N/A Cnestis; (4) absent.