The Distribution of Stomata of Passiflora edulis

Abstract

(1) Passiflora edulis (purple flower variety) has stomata on the epidermis of hypocotyl, cotyledon, leaf, stem-tendril, stem and epicarp, but there is no stoma on the upper face of leaf and on leaf-veins.
(2) The structure of stoma ofP. edulisbelongs to second-type consisting of two kidneyshape guard cells. Auxiliary cells of stoma on hypocotyl, cotyledon and lamina are same in size and shape of epidermal cells of each part, but on petiole and stem those are smaller than surrounding epidermal cells of each correspondent part, and on stem-tendril two types mentioned above exist togather. On epicarp, auxiliary cells are usually 6 and same size as small as epidermal cells of epicarp.
(3) Distribution of stomata on hypocotyl, cotyledon, lamina, stem, stem-tendril and epicarp are uniform, but on petiole it is not so, as density of distribution on apical part is larger than that of basal part and that of lower face of petiole is larger than that of upper face. On stem, one year old stem has uniform distribution of stomata but on the stems older then two years distribution of stomata is unequal as there is maldistribution of epidermis as the result of periderm formation.
(4) Stomata on lamina and epicarp are arranged at random directions, but on cotyledon, petiole, hypocotyl, stem and stem-tendril directions of arrangement are fixed, that is, on cotyledon stomata are arranged paralleling to longitudinal axis of cotyledon and on petiole, hypocotyl, stem and epicarp stomata are arranged paralleling to vascular bundle.
(5) Density of distribution of stomata gets smaller in order of lamina, lower face of cotyledon, upper face of the same, stem of one year old, hypocotyl, stem-tendril, epicarp and petiole, and numbers of stomata in 1 square millimetre corresponding to each part mentioned above are 352.2, 188.0, 55.2, 44.8, 27.2, 20.0, 15, 1 and (3-5) respectively.
(6) Periderm formation caused by growth in thickness of stem develops locally and partially and epidermis does not fall down, so even on stems older than six years epidermis exists in living and stomata also exist yet not losing function. But, as periderm-formation proceeds more and more stomata are gradually destroyed mechanically.
(7) The size of stoma varies according to the organ or part on which stomata exist. As growth in thickness of stem advances size of stoma on stem becomes larger gradually.