DEVELOPMENT RHYTHMS OF THE GENUS (NAWORTHIA NAW.) IN THE GREENHOUSE OF BOTANICAL GARDEN (INSTITUTE) OF ACADEMY OF SCIENCES OF MOLDOVA N. A. Todirash Botanical Garden (Institute) of Academy of Sciences of Moldova

Summary. In this article are presented the results of the systematical analysis of the representatives of Hawortia available in the collection of Botanical Garden of Republic of Moldova. All of the collection are divided into sections according to classifi cation criteria proposed by Jacobsen Are presented the phenology spectrum of Haworthia genus

Introduction The main indicator of adaptation to new conditions of growth is the passage of all stages of development: normal vegetative growth and a successful transition to the generative development. Because fruit set and seed maturation tropical and subtropical often is associated with certain kind of insect pollinators, which are absent in the new environment, the main criterion for acclimatization of plants is the presence of the fl owering phase. Regularity and stability and the appearance of fl owering can serve as a criterion of successful introduction. In this regard, long-term phonological observations of exotic species are important for successful introduction.

Materials and methods Object our study were of the species of genus Haworthia Haw, represented in the greenhouse collection of the Botanical Garden. Haworthia is a genus of fl owering plants within the family Xanthorrhoeaceae, subfamily [1]. They have a small (usually 20 cm high) solitary or clump-forming. Some species have fi rm, tough leaves, usually dark green in color, whereas other are soft and semi-translucent. Their fl owers are small, white and very similar between species. But their leaves show wide variations even within one species. The classifi cation of the fl owering plant subfamily Asphodeloideae is weak and concepts of the genera are not well substantiated. Haworthia is similarly a weakly contrived genus consisting of three distinct groups: subgenera Haworthia, Hexangularis, and Robustipedunculares. Related genera are Aloe, Gasteria and Astroloba and intergeneric hybrids are known. 355 The genus Haworthia is named after the botanist Adrian Hardy Haworth. Bayer recognizes approximately 61 species whereas other taxonomists are very much less conservative (1999, Haworthia Revisited, Umdaus Press). The species are endemic to South Africa, Swaziland, Namibia and Maputoland. The plants are small, forming rosettes of leaves from 30mm to exceptionally 300mm in diameter. These rosettes are usually stemless but in some species stems reach up to 500mm. Their fl owers are small, white and very similar between species. There are differences in the fl owers of the three sub-genera that botanists have curiously considered inconsequential although the differences between species in the same subgenus defi nitely are. The roots, leaves and rosettes do demonstrate some generic differences while wide variations occur even within one species. Because of their horticultural interest, the has been dominated by amateur collectors and the literature is rife with misunderstanding of what the taxa actually are or should be. A collection of Haworthia genus in the Botanical Garden contain of 31 species belonging to 12 sections in accordance with the classifi cation of Jacobson (3), which divides with 20 sections based on the structure of the stem and leaf. The most commonly (four species) in the collection is represented Section Corctatae Bgr.(II) - Haworthia cassutha Bak, Haworthia coarctata (Salm) Haw., Haworthia glauca Bak., Haworthia herrei v. Poelln.; VII Section Limpidae Bgr. (- Haworthia angustifolia Haw., Haworthia obtusa Haw., Haworthia vitata Bak., Haworthia obtusa Haw. v.variegata hort., IX (Margaritiferae Haw.) - Haworthia fasciata (Wild.) Haw., Haworthia glabrata (Salm.) Bak., Haworthia margaritifera (L.) Haw., Haworthia radula (Jacq.) Haw., XIV (Retusae Haw.) - Haworthia retusa (L) Haw., Haworthia mirabilis Haw., Haworthia nitidula v. Poelln., Haworthia ryderiana v.Poelln, Haworthia tuberculata v. Poelln. There are two Haworthia species from Section III Denticulatae Bak. Haworthia altilinea Haw., Haworthia mucronata Haw., Section XII - Obtusatae Bgr. - Haworthia cymbriformis (Haw.) Duv., Haworthia lepida GGSmit, Section XV- Rigidae Haw. - Haworthia rigida (Lam.) Haw., Haworthia rigida (Lam.) Haw. v. One species presented rigida Section I Arachnoideae Haw. -Haworthia pallida Haw.; VI Limifolia G.G. - Haworthia limifolia Marl.; XIII Planifoliae Bgr. - Haworthia aristata Haw.; XVIII-Tessellatae (Salm.) Bak.- Haworthia tessellate (Salm.) Haw.; XIX Tortuosae Haw- Haworthia tortuosa Haw. To study the characteristics of the genus Haworthia were conducted phenological observations for plants collection. The study was conducted for three years. Every ten days, there were monitored phases of plant 356 Table 1 Table Months I II III IV V VI VII VIII 1X X XI XII 1 1 2 3 1 1 2 3 1 1 2 3 The phenology spectrum of Haworthia genus coarctata (Salm) Haw. 3 2 3 1 3 liliputana Uitew. Hawortia altilinea Haw Hawortia angustifulia var Hawortia angustifolia Haw. Bak.Hawortia cassuta 2 Hawortia 1 1 Hawortia aristata Haw.Hawortia aristata 2 2 1 6 4 5 3 N Species Year 357 3 3 (Haw.) Duv.cymbriformis (Haw.) 2 fasciata (Willd.) Haw. 3 2 3 3 3 Hawortia Hawortia 1 Hawortia glabrata (Salm) Bak. 1 Bak 2 Hawortia glauca 1 v.Poelln Hawortia 2 3 Herrei 2 1 Marl. Hawortia lemifolia 2 1 1 G.G.Smith Hawortia lepida 2 1 3 8 9 7 11 12 10 13

358 1 1 2 3 3 3 obtusa Haw. variegata 3 2 3 3 3 1 Hawortia margaritifera (L) Haw. Hawortia margaritifera Haw.Hawortia mirabilis 2 Hawortia Poelln nitidula v. 1 Haw. Hawortia 2 obtusa 1 2 Hawortia 1 Haw. Hawortia palida 1 2 1 Hawortia mucrocanta Haw. Hawortia mucrocanta 2 17 18 19 20 16 15 14

359 3 3 3 3 regida (Lam.) Haw. var regida 3 reinwardtii (S.D.) Haw. 2 3 3 2 1 Hawortia planifolia Haw. 1 Hawortia 2 radula (Jacq.) Haw. 1 2 Hawortia regida (Lam.) Haw. 1 2 Hawortia 1 Hawortia 1 Hawortia retusa (L.) Haw. 1 Hawortia 2 Poelln ryderiana v. 1 2 3 21 22 23 24 25 26 27

360 1 1 1 1 tuberculata v. Poelln 3 2 1 1 tesselata (Salm) Haw. 2 3 Hawortia tortuosa Haw. Hawortia 3 2 Hawortia vitata Bak. 1 3 2 3 Hawortia 3 30 31 28 29

361 development, namely the beginning of budding (infl orescence emergence), phase coated bud, beginning of fl owering (fi rst fl ower opening), the phase of mass fl owering, late fl owering (last fl ower wilting). The phase of development was marked even if it was observed in only one plant of the collection (2).

Results and disscusions The results are presented in Table 1.

As can be seen from the table in the Botanical Garden greenhouse bloom was observed in 30 of the 31 species of collection. During the experiments period only Haworthia retusa (L) Haw. (Section XIV) did not blossom The most stable bloom from May to September were observed at the following types of Haworthia cassutha Bak, Haworthia coarctata (Salm) Haw., Haworthia reinwardtii (SD) Haw. Haworthia glauca Bak. (Section II), Haworthia angustifolia Haw. (Section VIII) Haworthia tessellate (Salm.) (Section XVIII) Haworthia aristata Haw., Haworthia planifolia Haw. (Section XIII) Haworthia margaritifera (L.) Haw. (Section IX).Flowering not confi ned to the particular period during the year was observed on Hawortia vitata Bak. (Section VII) u Hawortia altilinea Haw. (Section III). Fruiting of the species within this genus conditions was not observed.

Conclusions Thus we can conclude that the species of the genus Hawortia successfully passed introduction and acclimatization in greenhouses of the Republic of Moldova and can be successfully used for landscaping interiors. Bibliography 1. Дворянинова К. Ф., Шестак В.И., «Тропические и субтропические растения в оранжереях Ботанического сада АН МССР», «Штиинца» Кишинев 1985 стр. 136-137. 2. «Методика фенологических наблюдений в ботанических садах», Москва, 1972, 135 стр. 3. Jacobson H. “Das Sukkulenten lexicon.’ Veb, Gustav Fischer Verlag.- Vena, 1970, S. 217 -238.

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