Comparative leaf anatomical studies of some Mallotus Lour. (Euphorbiaceae) species

Abstract

A comparative study was undertaken on the leaves and petioles of 16 species of Mallotics in order to investigate anatomical variations of potential in species identification. There is a range of characters which varies between species. These include the outline of the midrib and petiole in transverse sections, the shape of the vascular tissue in midribs, the presence of central bundles in the petiole, the presence of terminal sclereids, enlarged tracheids, presence or absence of non-glandular trichomes, and parenchymatous sheaths in vascular bundles. A combination of these characters may be used to identlfy species. Anatomical data support the placing of only a few species into the respective sections.

Comparative petiole anatomy of cassava (Manihot) species

“…Nassar et al (2008) reported the occurrence of laticifers in Manihot stems only in the cortex and primary and secondary phloems, differing from our findings. The vascular system of the petiole is cylindrical and is interrupted by the phloem around the xylem, and has been described in M. glaziovii (Mendonça, 1992) and other species of the Euphorbiaceae (Hussin et al, 1996).…”

Leaf anatomy of Mallotus and the related genera Blumeodendron and Hancea (Euphorbiaceae sensu stricto)

“…A detailed leaf anatomical study of some Mallotus and Hancea spp. had already been conducted by Rittershausen (1892) and Hussin, Wahab & Teh (1996). Based on some leaf anatomical characters, Rittershausen (1892) suggested that Mallotus integrifolius Müll.Arg.…”

“…and should be excluded from Mallotus on the basis of the presence of intra‐xylary phloem in the stem. More than a century later, Hussin et al . (1996) published a leaf anatomical article on 15 species of Mallotus from the Malayan region and one from Thailand.…”

“…Their study also included four species which now belong in Hancea ( H. kingii , H. penangensis , H. subpeltata and H. griffithiana ). Hussin et al . (1996) questioned the subgeneric classification of Airy Shaw, e.g.…”

Foliar architecture and anatomy of Bernardia and other genera of Acalyphoideae (Euphorbiaceae)

“…these attributes have been used to erect phylogenetic hypotheses (Gillespie, 1988;Levin, 1986;Levin & Simpson, 1994). In addition, since the 19th century, anatomical characters, especially those of laticifers (Pax, 1884;Metcalfe & Chalk, 1950;Rudall, 1987;Webster, 1994a), as well as wood (Hayden, 1980;Mennega, 1987;Hayden, 1994;Hayden & Hayden, 2000) and leaves (Hussin et al, 1996), have provided valuable information for the taxonomy of the Euphorbiaceae s.l. Trichomes, stomata and some other features of the foliar epidermis (Mueller, 1866;Solereder, 1908;Knoll, 1905;Metcalfe & Chalk, 1950;Webster, considered generic status for Bernardia sections Passaea and Traganthus.…”