Analele ştiinţifice ale Universităţii Al. I. Cuza Iaşi Tomul L, s. II a. Biologie vegetală, 2004 HISTO-ANATOMICAL LESS KNOW ASPECTS UPON SOME LAMIACEAE TAXA CAMELIA IFRIM *, IRINA TOMA ** Abstract: The present paper is focused on vegetative organs of seven species from Lamiaceae family. For each taxon we point out the histo-anatomical features of the vegetative organs that is less typical for Lamiaceae family and can be utilize for taxonomical diagnosis. Key words: Lamiaceae family, histo-anatomical aspects Introduction A lot of members of the Lamiaceae family have differents uses like medicinals and ornamentals plants. Information about their histo-anatomical features are numerous, both in the anatomical synthesis [4,5] or in the especial papers [1,3]. In our country are many studies about medicinal [6,7,8] or non medicinal species [9] belonging to Lamiaceae family. Most of the anatomical synthesis present some features, especially for the stem. Generally, the outline of the transverse stem section is rectangular and the collateral vaular bundles are well developed especially in the four angle of the axis and the central cylinder is delimited by an obvious endodermis. The collenchyma tissue forms well-defined groups in all four angles. Material and method The vegetal material is rresented by the roots, stems and leaves of seven taxa who belongs to Lamiaceae family: Ajuga rtans L., Ajuga rtans L. Variegata, and exotic taxa Perilla fruteens (L.) Britt. 'Nankinensis', Perilla fruteens (L.) Britt. var. japonica (Hassk.) Hara, and as well as Plectranthus coleoides Benth., Plectranthus coleoides Benth. Marginatus, and Plectranthus prostratus Gürke [2,10]. All the taxa were cultivated in the greenhouses of the Botanical Garden of Iasi. The fixing and processing of the material was done according to the usual protocol of the Vegetal Morphology and Anatomy Laboratory belonging to the Biology Dartment of the University Al. I. Cuza of Iasi. The sections were made transversal at the middle level of the root, of the stem and of the leaves. As well as there were made superficial sections at the leaf level. The obtained permanent prarations were analyzed and photographed at the Novex optical microope. * Botanical Garden "Anastasie Fătu" Iassy ** University "Al. I. Cuza" Iassy, Faculty of Biology 13
14 Results The information concerning the root structure of the Lamiaceae family is attered in the anatomical literature so we have to point the fact that this structure can be tetrarh (like Perilla fruteens 'Nankinensis') or pentarh (like both taxa of Plectranthus coleoides). The passing to the secondary structure can occur very early, even at the annual plants, like Perilla fruteens taxa. The stem (fig. A-J) can be erect (aerial) or prostrate (aerial or underground). We will refer to the rhizome, a prostrate underground stem of Plectranthus. In the botanical literature we didn t found any mention about a rhizom at the Plectranthus species. On our material we can observe that in the external part of the stem some suberized layers and some phelodermical layers are occur. The vaular area is composed by two concentrical rings: an external phloemic ring and a xylemic internal one. The endodermis is missing. We have been found that this organ have a rhizome structure, but future researches are still necessary. The outline of the stem transverse section can be different: ± circular (like at the rhizom of Ajuga rtans, Plectranthus coleoides, and Plectranthus coleoides Marginatus ), oval (at the aerial stem of Plectranthus coleoides, Plectranthus coleoides Marginatus and Plectranthus prostratus) or rhomboidal with rounded angles (at the aerial stems of both Ajuga rtans taxa). We point out the developing of a suber tissue (with 4-5 layers) and a phelodermis (with 4-5 layers) at the rhizome of the Plectranthus taxa. Sometime, the phelodermis tissue may have the collenchymatous cells. The collenchyma tissue may be developed like a complete ring at the rhizome of Ajuga rtans. In this last case, the hypodermal layer of the cork is collenchymatous and many islands of collenchymatous cells may be found even in the neighbourhood 2-3 layer of cork. By compariyng with other Lamiaceae stem structures, the cork does not end with a normal endodermis at the aerial stems of the Ajuga rtans and their variegated sorts, Perilla fruteens 'Nankinensis' and Perilla fruteens var. japonica and at rhizome of the Plectranthus coleoides and its variegated sort. At the last two taxa the most inner cork layer has cells aost arranged like an endodermoid. The vaular tissue forms numerous collateral bundles with different sizes, being sarated by the parenchymatic-cellulosical medullar rays. This aspect is very obvious at the Ajuga rtans aerial stem, which forms very small vaular interfaicular bundles, rresented by phloemic elements only. At the other taxa the four vaular bundles situated in the "corners" of the section are evidently more developed. The leaf structure (fig. K, L) is variable with the taxa. We want to point out a few features observed on our material. The petiole of Plectranthus coleoides, in transverse sections through the distal end, presents 2-3 subidermal layers of angular collenchyma. In the petiole of Perilla fruteens 'Nankinensis' the vaular tissue has a very interesting development. It seems to be form by two bundles, but each bundle is composes by a lot of small bundles.
The both taxa of Ajuga rtans leaf have an amphistomatic lamina, and the idermic cells have the external walls with irregular thickened. Conclusions The histo-anatomical structure of the vegetative organs of the Lamiaceae species has peculiarities, more visible at the exotic taxa Plectranthus and Perilla analyzed by us. In this paper we note the histo-anatomical aspects that can be useful for taxonomical diagnosis. BIBLIOGRAPHY 1. ASCENSAO, L., L. MOTA, M. DE M. CASTRO. 1999. Glandular trichomes on the leaves and flowers of Plectranthus ornatus: morphology, distribution and histochemistry. Ann. Bot., 84: 437-447 2. ENCKE, FR., G. BUCHHEIM, S. SEYBOLD.1994. Zander Handwörterbuch der Pflanzennamen. (15.Aufl.). E. Uer Verlag, Stuttgart 3. IFRIM, CAMELIA. 2002. Aspecte histo-anatomice comparative la doi taxoni din genul Glechoma L. Acta Botanica Horti Bucurestiensis, 30 (under press) 4. METCALFE, C.R., L. CHALK. 1950. Anatomy of the Dicotyledons. 1-2, Clarendon Press, Oxford 5. METCALFE, C.R., L. CHALK. 1988. Anatomy of the Dicotyledons. (2 nd ed.). I. Systematic anatomy of the leaf and stem. Clarendon Press, Oxford 6. RUGINĂ, RODICA, C. TOMA. 1995. Histo-anatomical researchs on some medicinal plants. V. Labiatae. An. şt. Univ. Al.I. Cuza, s. II, a. Biol. veget., 41: 17-22 7. TOMA, C., LĂCRĂMIOARA IVĂNESCU, MIHAELA NIŢĂ. 1995. Histo-anatomical contributions concerning some species of Salvia L. An. şt. Univ. Al.I. Cuza Iaşi, s. II, a. Biol. veget., 41: 7-16 8. TOMA, C., RODICA RUGINĂ.1998. Anatomia plantelor medicinale. Atlas. Edit. Acad. Române, Bucureşti 9. TONIUC, ANGELA, C. TOMA, ANCA AIFTIMIE. 1994. Histo-anatomical data upon the vegetative organs of the Stachys sieboldii Miq. An. şt. Univ. Al.I. Cuza Iaşi, s. II, a. Biol. veget., 40: 45-55 10. VOLKOVA, E.V. 1954. Plectranthus L Hérit. În: Flora SSSR, 21: 638-640. Izd. ANSSSR, Moskva, Leningrad Explanations of the figures A. Ajuga rtans L. - Rhizome structure (diagram) B. Ajuga rtans L. Variegata - Aerial stem structure (diagram) C. Plectranthus coleoides Benth. 'Marginatus - Rhizome structure (diagram) D. Plectranthus prostratus Gürke - Aerial stem structure (diagram) E. Plectranthus coleoides Benth. 'Marginatus - Rhizome structure (detail of central cylinder) F. Plectranthus coleoides Benth. 'Marginatus - Rhizome structure (detail of xylem) G. Ajuga rtans L. - Stem structure (detail of collenchyma) H. Plectranthus prostratus Gürke - Aerial stem structure (detail of suberized tissue) I. Perilla fruteens (L.) Britt. 'Nankinensis' - Prostrate stem structure (detail of central cylinder) J. Plectranthus coleoides Benth. Marginatus - Aerial stem structure (details of cork and central cylinder) K. Plectranthus coleoides Benth. - Petiole structure (details of collenchyma) L. Ajuga rtans L. Variegata - Upper and lower idermis structure (details) Abreviations - cambium; cel. - idermal cells; cel.st - stomatal cells; col - collenchyma; cut - cuticle; - idermis; fld - phellodermis; flg - ; - phloem; f - libriform; lc - pith cavity; - xylem; - pith; mx - metaxylem; par.fdm - fondamental parenchyma; px - protoxylem; p.t - trichome; rz. - xylemic rays; sb - suber; - cork; l lerenchyma 15
B lc cut A 0 100 µ C sb l sb fld end rz. 0 100 µ 16 D
mx mxl rz. f rz. F E cut col H G sb flg fld 17
cut col mx px l J I K col L cel st p.t par.fd 0 50 µ 18 cel.