The taxonomic significance of leaf anatomical characters in Cussonia and related genera (Araliaceae)

Abstract

The anatomy of the petiole, petiolule and leaf lamina of 20 Cussonia spp. is described and taxonomically evaluated. Comparisons are made with related taxa of Araliaceae: two Afro-Malagasy Schefflera spp., two Asian Schefflera spp. and Seemannaralia gerrardii. Transverse sections and epidermal peels (lamina only) were studied. The continuous collenchyma layer in the midrib, the absence of a hypodermis and papillate epidermal cells are characters shared between Afro-Malagasy Schefflera and Seemannaralia, and Cussonia and Seemannaralia share adaxial stomata, abaxial papillae on the lamina and similarly sized secretory canals in the petiole. Infrageneric groupings suggested by three types of petiolar vascular bundles correspond to one of the two existing infrageneric classification systems. Anatomical characters also contribute to a better understanding of species delimitation. The study has revealed six new generic apomorphies for Cussonia, namely the discontinuous, subepidermal collenchyma layer and the associated stomata in the petiole and petiolule, the adaxially invaginated and flattened ring of separate or connected bundles forming a narrow arc in the petiolules and the occurrence of arm palisade in the lamina. Leaf anatomical characters have greatly increased our understanding of relationships and circumscriptions at generic, infrageneric and specific levels in the taxa studied.

The taxonomic implication of leaf anatomy in tribe Sorbarieae (Spiraeoideae: Rosaceae)

“…해부학적인 형질은 현화식물의 분류군에 있어 분류학 적 위치와 유연관계 뿐 아니라 종 동정을 위해 이용되고 있다 (Solereder, 1908;Chalk, 1950, 1979;Agbaywa and Noukwu, 2004;Kharazian, 2007;Stuessy, 2008). 잎의 해부학적 형질 또한 최근까지도 다양한 분류군에서 연구되고 있으며, 그 분류학적 유용성이 검토되고 있다 (Gonçalves and Rodriigo, 2003;Noorbakhsh et al, 2008;Araújo et al, 2010;De Villiers et al, 2010;Millán and Kahn, 2010;Moraes et al, 2011;Almeida et al, 2013). 장미과에 대 한 해부학적 연구로는 Lee et al (2010)이 한국산 조팝나무 속의 엽병 해부를 통해 진단형질로써의 가치를 검토하고, 검색표를 제시한 바 있다.…”

A Review of Botany, Therapeutic Value, Phytochemistry, and Pharmacology of Cussonia Paniculata

“…The genus Cussonia Thunb. comprises about 22 species which are mainly trees or shrubs or occasionally subshrubs recorded in grasslands, woodlands, and forests of sub-Saharan Africa, the Arabian Peninsula (Yemen), and the Comoro Islands [40][41][42][43][44][45][46]. C. paniculata is widely used as a decorative and ornamental plant, as the species is frost-resistant and therefore recommended for rockeries, bonsai, and other gardens [42,[47][48][49][50][51][52][53][54][55].…”

Modern plant morphological studies

“…Vegetative anatomical traits are of great ecological and physiological significance (Carlquist, ) and often also prove useful in systematic studies at various taxonomic levels (e.g. De Villiers et al ., ; Zarrei et al ., ; Liu & Zhu, ). Here, Hernández‐Hernández et al .…”