J Syst Evol ›› 1990, Vol. 28 ›› Issue (3): 228-236.

• Research Articles • Previous Articles     Next Articles

Pollen Morphology and Epidermal Characters of Leaves in Convallarieae (s. l.)

Ma Li-Ming, Hong De-Yuan   

  • Published:1990-05-10

Abstract: The tribe Convallarieae (sensu Krause 1930) consists of 7 genera, i.e. Convallaria, Speirantha, Reineckia, Theropogon, Tupistra, Rohdea and Aspidistra, but now generally recognized as two tribes, Convallarieae (the former 4 genera) and Aspidistreae (the rest). Observed in this work were pollen morphology of 17 species and epidermal characters of leaves of 12 species. All the 7 genera are covered in observations. Pollen grains in Convallarieae (s. str.) are all monosulcate and boat-shaped (Plate 1: A-F). The exine is rather uniformly microperforate (Plate 1: A-F); only Theropogon is exceptional in this respect: it has rugulate exine (Plate 1: O, P). Tang and Zhang (1985) have pointed out the heterogeneity of Theropogon in this tribe. Pollen morphology in the tribe Aspidistreae is widely variable. The genera Tupistra and Rohdea were shown to have monosulcate and boat-shaped pollen grains. Their exine is perforate or reticulate (Plate 1: G-N). Pollen grains in the genus Aspidistra, however, are nonaperturate and spheroidal. The exine in the genus varies from crass-rugulate, variously gemmate to tuberculate-baculate (Plate 2; A-H). The pollen morphology of Aspidistra is therefore distinctly different from that of Tupistra and Rohdea, which supports the Nakai's (1936) establishment of the tribe Rohdeae for Tupistra and Rohdea. Therefore, Krause's Convallarieae is reasonably divided into at least three tribes, Convallarieae (Speirantha, Convallaria, Reineckia and Theropogon), Aspidistreae (Aspidistra) and Rohdeae (Rohdea and Tupistra). The pollen characters of all the 7 genera are shown in Table 1. The evolutionary trends of pollen morphology (aperture and exine) in the three tribes are discussed and our major view-points are shown in Fig. 1. Observations on epidermal characters of leaves show that in the Convallarieae (s. 1.) stomatal apparatuses are all anomocytic; cuticular layer on the upper epidermis is mainly striatethickened or rather uniformly thickened (Plate 2: J--P; Plate 3: A-C, F-N), whereas in the genus Convallaria the cuticular layer is squamosely thickened (Plate 2: I; Plate 3: D, E).The epidermal characters of leaves in the 7 genera are summarized in Table 2.

Key words: Pollen morphology, Evolutionary trends, Epidermal characters, Convallarieae, Aspidistreae, Rohdeae