ABSTRACT:Ten Fagoni a species grown in the Lib yan Desert wer e s ubject ed i n t his s tud y, Fagoni a arabica L., F. brugui eri DC., F. cretic a L., F . gluti nos a D elile, F. i ndic a Burm., F . microphylla P omel, F. sinaica Boiss ., F . schweinf urthii Hadidi, F. t enuifoli a St eud ., and F. t hebaica Boiss . A nat omic al c haract ers included t he inter nal str uct ures of bot h st ems and l eaves hav e b een inv estigat ed i n the present s tud y. T axonomical key has b een construc ted acc ording to t he int ernal struct ures of t he st em s and t he l eav es. The results of AN OV A test indicat ed that fiv e char act ers, number of p hloem fiber patches i n the cort ex, number of parenc hyma l ayers i n the c ortex, ratio betw een p hloem and Vasc ular tiss ue, rati o betw een phl oem and stem r adius and rati o between xyl em and stem radius, are highl y signific antl y diff erent within t he st udied speci es. The previous trials of cl assific ati on hav e b een discus sed acc ording to the obtai ned r esult s.

A The essential oil was extracted from the dried shoots of plant materials, twelve compounds were identified by Gas chromatography–mass spectrometry (GC-MS) analyses revealed that essential oil contains mainly  germacrene B, β-caryophyllene, Limonene, α-pinene, Germacrene D, β-Elemene, α-Copaene, α-Cadinol, Terpinen, Isoborneol, Camphene and Linalool. However, T. zanonii was specified by the presence of all assessed oils, while section Chamaedrys (T.barbeyanum) was characterized by the absence of α-pinene, α-cadinol and Isoborneol. Although, αpinene and α-cadinol were also absent in T.polium subsp. flavovirens, these were detected in the two other forms of T.polium. Contrary, Linalool and Terpinen were detected in the two forms of T.polium and not detect in subspecies. The Terpinen is also undetected in T.brevifolium, T.campanulatum and T.fruticans, which are belonged to section Teucrium.

The flora of Masalata Natural Reserve (MNR) in the north-Western section of Libya, 90 km east of the city of Tripoli was surveyed in terms of life forms and phytogeography. Distribution and abundance values of the recorded species were determined. A total 445 of flowering plants are identified, they are distributed in 249 genera and belonging 64 Families. Annuals are predominated life form (60.9%), while parasites are the lowest (0.22%). The mono-regional Mediterranean species constitute 62.02% of the other flora. Species which are primarily Mediterranean but in some cases bi-regional with 30.78% and pluri-regional account for 14.38%.

Ten Fagonia species grown in the Libyan Desert subjected in this study. The study focused on both micro-and macro-morphological characters by using Stereomicroscope, light Microscope and Scanning Electron Microscope (SEM). These species include Fagonia arabica L., Fagonia bruguieri DC, Fagonia cretica L., Fagonia glutinosa Delile, Fagonia indica Burm., Fagonia microphylla Pomel, Fagonia sinaica Boiss, Fagonia schweinfurthii Hadidi, Fagonia tenuifolia Steud. and Fagonia thebaica Boiss. This study has elucidated the importance of the vegetative macro characters in the taxonomy of the genus as first step in identification, especially the length of the spiny stipules and the type of leaf blade. Leaf or leaflet shape as well as margins and apices are of minor taxonomic importance. Microcharacters can be used to recess the identification and can be consider as the second step in identification. An identification key has been constructed and the previous trials of classification have been discussed according to the obtained results.