Fig. 6.

Sieve plate type in variant phloem. (A) Longitudinal radial section of Amphilophium crucigerum. Sieve tube elements bearing simple sieve plates. Detail of a simple sieve plate with large sieve pores, as seen in transverse section. (B) Longitudinal radial section of Bignonia campanulata. Sieve tube elements bear compound sieve plates with few sieve areas. (C) Longitudinal radial section of Fridericia samydoides. Sieve tube elements bear compound sieve plates with many sieve areas. (D) Ancestral character state reconstruction of the sieve plate types. (E) Ancestral character state reconstruction of the average number of sieve areas per sieve plate. Scale bar = 50 µm.