Nucellar and integumentary stomata in Zamia (Zamiaceae, Cycadales)

 

Photo credit: Google

Zamia floridana

Stomata on the ovules of Zamia floridana

by Shapiro S. (1951)

Seymour Shapiro, University of Michigan, Ann Arbor, Michigan, USA

in Amer. J. Bot. 38: 47- 53

Scan

Scan 1

Advertisements

Stomata in Zamia (Zamiaceae – Cycadales)

Photo credit: Google

Zamia acuminata

Comparative anatomy of leaflets of Zamia acuminata and Z. pseudomonticola (Zamiaceae) in Costa Rica.

by Acuña-Castillo R. H., Marín-Méndez W. (2013)

 

in Revista de biologia tropical 61(2):539-46 · June 2013 – DOI: 10.15517/rbt.v61i2.11146 ·

PubMed – 

https://www.ncbi.nlm.nih.gov/pubmed/23885572

2_zamia_pseudomonticola
Zamia pseudomonticola – https://s9.postimg.org/x6yy190f3/2_zamia_pseudomonticola.jpg

Abstract

The genus Zamia is morphologically and ecologically the most diverse of the order Cycadales. Throughout its history this genus has been restricted to the New World and is presently almost entirely restricted to the Neotropics. Unusual anatomical traits of the leaflets, such as the sunken stomata and thick cuticle, are common in this and related genera.

The objective of this research was to study and compare the leaflet anatomy of Zamia acuminata and Z. pseudomonticola and establish possible phylogenetic relationships between the anatomical traits and the near relatives of these species. The leaf material was obtained from living plants and then processed for electron microscopy study.

We found that both species are very similar to each other and to Z. fairchildiana, and that they share several unusual traits with other species of the genus, such as the parenchyma morphology, the spatial distribution of tissues between the veins and the stomata morphology.

The main differences between these species were seen in their fiber clusters and in the abundance of trichome basal cells on the epidermis. The anatomical similarities between the three species could be the result of their close phylogenetic relationship and the divergences between them could be the result of recent speciation during the Pleistocene, resulting from geological changes in Southern Costa Rica.

Stomata in Cycadales

screen-shot-2017-01-28-at-21-37-17

The leaf epidermis of the Cycadales

by Greguss P. (1957)

Botanical Institute of the University Szeged

in Acta Biol. Szeged 3: 181-164. –

http://acta.bibl.u-szeged.hu/21435/1/biologica_003_151-164.pdf

screen-shot-2017-01-28-at-21-35-26

FLORI N in his excellent work deals in detail with the leaf epidermis of Coniferae and Cordaites, precisely with the structure of the stomas and he reaches important phylogenetic conclusions.

He describes briefly in his paper the leaf structure of some types of the extinct Psilophyta and Pteropsida, but he does not deal with the leaf-structure of Cycadales, especially the stoma.

We get acquainted with the leaf-epidermis of many extinct Pteridospermae and Cycadales by the recent paleontology findings. They are very difficult to identify as we have no synthetic work which deals with the structure of leaf epidermis of Cycadales, at least by photo. This work intends to retrieve the lack, by describing the structure of the leaf epidermis of living Cycadales and wishes to help the paleontologists at the identification of the paleontology findings.

screen-shot-2017-01-28-at-21-33-31

Summary

On studying the structure of leaf epidermis of the characteristic species of the above treated 8 genera more precisely that, of the structure of the stoma located among the epidermis cells thoroughly, it can be stated, that the genera of Cycadales can be differentiated from one another according to the structure of the leaf epidermis.

Their epidermis or stoma structure resembles that of the Coniferales. There are some types e. g. Cycas, which have no similarity with. Coniferales, the stoma structure of which resembles that the air gap is exhibiting craterous structure of Marchantia. The resemblance is really striking!

screen-shot-2017-01-28-at-21-31-33

On the other hand, there are some genera, which show similarity with the stoma structure of the extinct Pteridospermae, e. g. Lyginodendron oldhamium.

The aim of this short paper is to draw conclusion from the comparison of the structuré of the leaf print in fossils concerning the genetic relation with living forms.

The aim of the following detailed communication will be to study not only the structure of the leaf epidermis of Cycadales, but the structure of the leaf’s and stem’s internal organisation too. I hope to publish it soon.

screen-shot-2017-01-28-at-21-28-42

Stomatal apparatus in Encephalartos gratus (Zamiaceae)

 

Ontogeny of Pinnal epidermis and stomatal apparatus in Encephalartos gratus Prain

by Su J., Li N., Lin J. Z. (2008)

SU Junxia (Coll. Of Life Sci., Shanxi Normal Univ., Shanxi, Linfen)

LI Nan (Shenzhen Fairy Lake Botanical Garden, Guangdong, Shenzhen)

LIN Jianzhao (Agriculture Coll.,Guangxi Univ., Guangxi, Nanning)

in Xibei Zhiwu Xuebao 28 (11): 2208-2216 –

https://www.researchgate.net/publication/285666302_Ontogeny_of_Pinnal_epidermis_and_stomatal_apparatus_in_Encephalartos_gratus_Prain

Abstract

The ontogeny of pinna epidermis and stomatal apparatus in Encephalartos gratus Prain have been observed with lm and sem.

The results are as follows:

(1) the epidermal cells change mainly in cell elongation and cell wall-thickening during the development of pinna.the epidermal cuticula occur continuously.

(2) the development of stomatal apparatus can be divided into three stages: guard mother cell, young guard cell and adult guard cell; stomata1 apparatus are haplocheilic or perigenous in origin, and the mature stomata are monocyclic type.

(3) during the development of pinna, the stomatal density is very low at first, then raises rapidly to the peak value, and finally drops gradually to the fixed one.

(4) a few of stomata develop into mature earlier than others.

(5) the pinnal epidermis mature from the base to the top.