دراسة تشريحية ومظهرية لبعض أنواع الجنس Portulaca L. (Portulacaceae) النامية في محافظة كربلاء

Anatomical and morphological study of some species of the genus Portulaca L. (Portulacaceae) growing in Karbala Governorate

Abstract

Four species belong to the genus Portulaca L. from family Portulacaceae in Iraq has been morphologically and anatomically studied. The species including : P.afra ,P.umbraticola , P.oleracea ,P.grandiflora .
The samples of plants collected by The Researcher from the fields and gardens in Kerbala city frome the date (1-10-2020). Morphological feature of stems, leaves, inflorescences , flowers , fruit were studied and the taxonomic importance of each character and it’s variation was discussed . the species P.afra separated from the other studied species by the Quantitative characters as high of plant and diameter of stem which was biggest in P.afra because It was perennial shrub but the other species were annual herbaceous plants ,and the smallest one was the species P.umbraticola . so the characters of the diameters and shape of the blade and apex ,and Phyllotaxy were important in separate the species from each to other , and the presence of Wight hairs on the base of leaves in ,P. umbraticola , P. oleracea ,P. grandiflora was very important in separate the species from P .afra which was no hair found on Its leaves base , so the diameters of that hair was useful to separate between the other species , which longest hairs found in P. grandiflora,and the smallest one found in P. oleracea . the shape of subsidiary cell of stomata was useful to separate between the studied species ,So the diameters of stomata and stomata complex was useful too.

The indumentum has important taxonomic value to distinguished between the studied species ,present study record presence of indumentum on the leaves epidermis for the first time ,the microhairs in P.oleracea and P. grandiflora . The Quantitative characters of floral parts as sepals , petals, filaments, anthers ,style ,stigma ,ovary and capsule , were useful to separate the species each to other .
Anatomical characters seen in epidermises of the stems, leaves , roots , transverse section of the stems and roots have been studied for the first time for the species P.afra ,P.umbraticola،. Most anatomical characters were proved to be of diagnostic value, as diameter and number of ordinary epidermis cell on upper and lower epiderm ,the species P.afra showed smallest ordinary epidermis cell and highest in number from the other species , and these characters distinguished between the other species . so the type of stomata have important value to separate the studied species from each to other ,in P.afra the actinocytic type was presence, and It recorded for the first time in epidermis which belong to the family Portulacaceae , and with comparing with other studied species ,the paracytic type was the predominant in P. grandiflora , and the tricytic type predominant in P.umbraticola , while the tetracytic type was the predominant in P.oleracea ,the shape of subsidiary cell of stomata give important to separate between the species , So the diameter of stomata and stomata complex has important value too.

The indumentum has a great taxonomic value to separate the species each to other, the present study record presence of indumentum in leaves epidermis for the first time in the studied species ,the microhair in P. grandiflora and P.oleracea ,while in P.umbraticola there was a big papillae in crescent shape ,in P.afra there was a big dome shape glandes with numerous cell, while in all past study they were not record any indumentum in P. grandiflora and P.oleracea ,and there were no anatomical study about P.umbraticola and P.afra and the present study was the first .
The study also included the type of crystals ,in which the presence of crystals and the type of It have a taxonomic value in isolating the studied species , the Star or Druses crystals observed in all studied species , while a Big and Small prismatic crystals in different shape as rectangular, square and rhomboid crystal shape record only in P.umbraticola and P.oleracea ,but the Sphaeraphides crystals saw only in P.oleracea and this characters was be useful in isolating the species.
The cross section study of the stem produced important anatomical characters through of thickness of :epidermis ,cortex ,vascular bundles , xylem , phloem and pith . the thickness of all stem tissues in species P.afra was a big more than the stem tissues of other studied species, because the diameters of stem of it was too big ,so the study found a big spaces in cortex of P.afra , which was not found in other species ,so the stem epidermis showed important anatomical characters helping in isolating the species as diameters and shapes of ordinary cell .the papillae was found in stem epidermis of species P.afra , but there were no indumentum in stem epidermis for other studied species .
The study revealed in presence of different crystal in their type and shapes on stem epidermis , the Star or Druses crystals found in all studied species , the Big and Small prismatic crystals found only in P.umbraticola and P.oleracea ,while the sand crystals found only in P.oleracea and that character was very useful in separate the species . The root section and root epidermis ,many characters were useful in isolating the studied species
Figures and plates for all vegetative, reproductive organs epidermis and sections were prepared for all species.In conclusion two species and three varieties were recognized for Iraq .
, So the characters of pollen grain was studied ,and there was variations between the species in diameters and ornamental of bollen graian