Nine types of stomata in Zanthoxylum

Leaf, stem bark and fruit anatomy of Zanthoxylum armatum DC. (Rutaceae)

Barkat U., Muhammad I., Ghulam J., Imtiaz A., (2014)

Barkat Ullah, Muhammad Ibrar, Ghulam Jelani, Imtiaz Ahmad,

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Pakistan Journal of Botany 46(4): 1343-1349 –

https://www.researchgate.net/publication/286904994_Leaf_stem_bark_and_fruit_anatomy_of_Zanthoxylum_armatum_DC_Rutaceae

Fig. 5. Various types of stomata in the lower epidermis of Zanthoxylum armatum leaf, a. Anomocytic; b. Actinocytic; c. Actinostephanocytic;d. Staurocytic; e. Laterocyclocytic; f. Brachyparacytic; g. Brachyparatetracytic; h. Hemiparacytic; i. Stomatal cluster

Abstract

Zanthoxylum armatum DC. (Rutaceae) is an important medicinal plant. The present study deals with anatomical exploration of the leaf, stem bark and fruit of this plant. Leaf of Z. armatum is bifacial, compound and punctate with glabrous surfaces having a single layer of epidermis and palisade mesophyll. The leaf has a Palisade ratio ranged from 6.00 to 9.00 (8.2 +/- 0.32). Vein islets and vein termination number were 14-21 (16.8 +/- 0.64) and 17-21 (19.1 +/- 0.43) per mm(2) respectively. The vein-islets were quite distinct with squaresh, elongated, polygonal or irregular in shape bounding many forked and unforked vascular branches. Adaxial surface of Z. armatum leaf midrib was planoconvex while the abaxial surface was semicircular in appearance. The diagnostic feature of the leaf was the complete absence of any kind of trichomes or any other appendages. The leaf showed prominent oil cavities.

Nine types of stomata with different frequencies and other dimensions were observed. Brachparatetracytic stomata was the most frequent stoma (80%) followed by actinostephanocytic (40%) and then straucytic and brachyparacytic (30%) each. Hemiparacytic and stomatal cluster were the rarely occurring stomata (10% each) present on the lower epidermis of the leaf. Stomatal cluster, which is considered to be a special leaf epidermal feature and reported only in few genera of vascular plants, was also recorded in this plant.

Bark and fruit anatomy of Z. armatum showed different tissue arrangement. The seed was non endospermic and contains an elongated embryo. The present study will be helpful in the phylogeny and taxonomic description of this important medicinal plant.

Published by

Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.

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