Pelargonium reniforme is currently divided into two subspecies, P. reniforme subsp. reniforme and P. reniforme subsp. velutinum. The species falls into section Reniformia along with the closely-related P. sidoides. Observations of the section showed some discrepancies in the current taxonomy; mainly floral variation that was not recorded in the descriptions of the subspecies of P. reniforme, particularly the differences in hypanthium lengths. Patterns of variability were analysed using both morphometrics and inter simple sequence repeat (ISSR) data for P. reniforme (both subspecies), and P. sidoides. Results showed no support for the current subspecific division of P. reniforme but also no support for the current status of P. sidoides as a separate species. However, both morphometric and ISSR data show some evidence for the existence of two distinctly separate groups within P. reniforl1le subsp. velutinum as two distinct types have been recognized: those with bright pink flowers with long tubes (up to 70mm), and those with pale pink flowers with shorter tubes (as little as 8mm). These two forms have been found in a single population (Grahamstown), where they occur sympatrically, as well as in monomorphic populations. Analyses of the processes thought to be responsible for the observed patterns were conducted on the Grahamstown population. Observations of pollinators suggest that long-tongued insects (Butterflies, Nemestrinid flies) pollinate the long-tubed flowers and short-tongued insects (Bombyliid flies, long-tongued bees) pollinate short-tubed flowers. However, analysis of selection gradients in the population, indicate no directional selection is occurring for hypanthium lengths. The results of this thesis show that selection is occurring within Pelargonium reniforme, but at this time, selection is not strongly directional and floral differences are maintained, even when floral forms occur sympatrically. It is suggested that a review of the taxonomy be undertaken as well as additional pollination and selection studies to confirm suspected taxonomic groupings and relationships between the floral forms respectively. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Pelargonium sidoides has been used for centuries in traditional medicine in Lesotho and South Africa as well as globally in modern medicine. Consequently P. sidoides tubers have been wild-harvested extensively in Eastern Cape and Lesotho to meet the growing trade demand. In recent years, the number of plant gatherers intending to supply markets and generate incomes have increased. Tubers are targeted because they contain medicinal properties. The medicinal compounds in the tubers are thought to be highly correlated with colour, with their concentration increasing as the colour develops towards dark-red. Dark-red coloured tubers seem to be preferred by the Pelargonium industry and are considered to be mature. Repeated harvesting of P. sidoides plants from the wild has been reported to result in localized population declines. This is exercabated by harvesting methods currently used which involve entire removal of the plant and not filling up harvest holes to safeguard tuber remnants left in the soil. Although various studies have investigated the impacts of such harvesting operations on P. sidoides wild populations, these studies have not provided information on tuber recovery rate and suitable recommendations to ensure sustainable harvest of P. sidoides from the wild. Therefore this study investigated (i) rate of tuber recovery in P. sidoides plants, (ii) impacts of wild harvest on its tuber recovery and (iii) made recommendations on sustainable harvest options for the species. The investigations were made using linear and non-linear regression models and ANOVA. Comparisons were done for “lowveld” (Eastern Cape) and “highveld” (Lesotho and Free-State) vegetation regions. The rate of P. sidoides tuber recovery was measured by tuber recovery colour and biomass in previously wild-harvested sites. Tuber regrowth rate in cultivated sites was also investigated in the same manner to determine prospects for cultivation. Time since last harvest was found to affect tuber recovery colour and biomass. As time since last harvest increased in the “lowveld” and “highveld” vegetation regions, tuber recovery colour and biomass also increased (lowveld- r2= 0.63, P < 0.05, d.f = 7 and highveld- r2= 0.55, P < 0.05, d.f = 5). In cultivated sites, only tuber regrowth using biomass was found to increase positively with time when study sites from the “lowveld” and “highveld” vegetation regions were combined (r2= 0.68, P < 0.03, d.f = 8). P. sidoides tuber recovery size was found to be smaller in previously wild-harvested sites compared to tuber size in unharvested control sites in the “lowveld” and “highveld” vegetation regions (lowveld- F11,95= 9.7226, P < 0.001, highveld- F23,99= 7.0519, P < 0.001). Cultivated plants also had more tuber regrowth size than tuber recovery size of previously wild-harvested sites showing that cultivation can be a viable option to produce the resource and contribute to the conservation of the wild resource. ii To ascertain under which scenarios P. sidoides can be harvested sustainably in the wild, factors which affect sustainable harvesting of P. sidoides such as effects of depth of harvest hole, mother tuber size (biomass), canopy area and altitude on tuber recovery biomass, tuber recovery colour and number of stems/plant were explored. Although results that were obtained varied, filling harvest holes with soil post-harvest increased tuber recovery biomass meaning that this factor can be included in P. sidoides harvesting guidelines. Furthermore, tuber and tuber recovery biomass tended to increase with an increase in canopy area suggesting that canopy size can be used as a surrogate for tuber size (tuber recovery biomass r2= 0.81, P < 0.05, df = 7, tuber biomass- r2= 0.57, P < 0.05, df = 7). The findings of this study revealed that tuber recovery colour and biomass in previously wild-harvested sites increased positively with time. P. sidoides plants were found to require ≥8 years for tuber recovery to develop the dark-red colouration and ≥10-15 years for previously wild-harvested plants to reach pre-harvest biomass. Furthermore, tuber recovery size in previously wild-harvested sites was found to be smaller compared to tuber size in unharvested sites even after 8 years since last harvest suggesting that tuber recovery size has not reached pre-harvest size after this period. Hence this confirms that even a single return harvest event within a 10 to 15 post harvest period can negatively affect wild populations of P. sidoides. This period is however too long for a sustainable Pelargonium industry thus questioning wild harvest as a viable methodology without rigorous ongoing monitoring and management of wild harvest sites. This is despite training on sustainable harvest, such as harvest methods provided by the Pelargonium industry. Conversely, prospects for cultivation as a viable alternative to wild harvest seem promising since cultivated plants only required ≥9 years to attain similar biomass to that of unharvested wild plants. Given that it is unclear what the Pelargonium industry considers as commercially acceptable for P. sidoides tuber characteristics, the tuber regrowth rate of ≥8years in cultivation may be shortened to meet trade specifications. The study also showed that for sustainable wild harvest of P. sidoides, harvest operations should entail effective closure of harvest holes with soil to ensure the survival of tuber remnants. Additionally, plants with bigger canopies may be targeted when harvesting P. sidoides in previously wild-harvested and new harvest areas. It must be noted though that a thorough investigation is needed to ascertain whether canopy size can be confidently used as surrogate for tuber size. Therefore further research into sustainable harvest methods for P. sidoides is recommended, and direct longer term monitoring of selected sites would be useful. More research is also needed on tuber colour development in cultivated plants and what constitutes commercially harvestable tubers.

Thesis (PhD)--Stellenbosch University, 1994. / ENGLISH ABSTRACT: Fifty nine species were studied in this taxonomic treatment of section Hoarea (Sweet) DC. of the genus Pelargonium L'Herit., which was last revised by Knuth in 1912. The majority of species occur in the winter rainfall area of the south-western Cape, but some species occur in the eastern Cape, a region of winter and summer rainfall. A few species also occur in the summer rainfall area in the central Karoo. Morphological, leaf anatomical, palynological and geographical data were studied in order to delimit the taxa and to determine their relationships. Eight new species were described and several name changes were made. Diagnostic features of the section are the regularly or turnip-shaped tubers with numerous dark brown peeling tunics or periderms and apically a short flattened stem from which the leaves and scape emerge. The zygomorphic flowers are almost sessile, because the pedicels are very short (0,5--1 mm) and the hypanthia long (6--100 mm). A large variation occurs in leaf form and floral structure, and the section is divided in 14 different floral groups, mainly based on the structure of the androecium and the tectum of the pollen grains, although petal form and size are also considered in clustering the species. Section Hoarea with its deciduous geophytes and sometimes extremely zygomorphic flowers, exhibits advanced morphological characters. Because of the large variation in the structure of the androecium, pollination biology was probably one of the major driving forces in the evolution of the section, and the annual rainfall plays an important role in the distribution patterns of the different species. / AFRIKAANSE OPSOMMING: Neen en vyftig spesies is bestudeer in hierdie taksonomiese ondersoek van seksie Hoarea (Sweet) DC. van die genus Pelargonium L'Herit., wat laas deur Knuth (1912) hersien is. Die meerderheid van die spesies kom in die winterreenstreek van die suidwes Kaap voor, maar sommige spesies word ook in die Oos-Kaap, wat 'n winter- en somerreenstreek is, aangetref. Enkele spesies kom in die somerreenstreek van die sentrale Karoo voor. Morfologiese, blaaranatomiese, palinologiese en geografiese data is bestudeer om die verskillende taksons af te baken, en terselfdertyd verwantskappe tussen die onderskeie spesies te bepaal. Agt nuwe spesies is beskryf en verskeie naamsveranderinge is gemaak. Diagnostiese kenmerke van die seksie is die reelmatiggevormde of raapvormige wortelknol met verskeie afskilferende donkerbruin periderms en apikaal 'n verkorte stingel waaruit blare en 'n bloeispil groei. Die sigomorfe blomme is byna sittend, aangesien die blomstele uiters kort is (0,5--1 mm) en die hipantiums relatief lank (6-- 100 mm). 'n Groot variasie in blaarvorm en blomstruktuur kom voor, en die seksie word in 14 verskillende blomvorms verdeel. Hierdie blomvorms is hoofsaaklik gebaseer op die struktuur van die andresium en tektum van die stuifmeelkorrels, alhoewel kroonblaarvorm en -grootte ook 'n rol gespeel het in die onderverdeling van die seksie. Seksie Hoarea met sy bladwisselende geofiete en soms uiters sigomorfe blomme, vertoon gevorderde morfologiese kenmerke. Die groot variasie in die struktuur van die andresium dui op 'n moontlike prominente rol wat die bestuiwingsbiologie gespeel het in die evolusie van die seksie, en die jaarlikse reenval speel 'n belangrike rol in die verspreidingspatrone van die verskillende spesies.

Thesis (MTech (Horticultural Science))--Cape Peninsula University of Technology, 2016. / This aim of this study was to investigate the viability of growing P. tomentosum in deep water culture (DWC) hydroponics and to assess the effects of various methods of oxygenating the nutrient solution with regards to growth, development and chlorophyll responses. The experiment was conducted over a period of 74 days. In chapter 3, 16 different methods of oxygenation were applied to 9 replicates. The control had passive aeration. The treatments were made up of air-pumps, vortex oxygenators and the application of hydrogen peroxide (H2O2) at various frequency intervals; these were combined with each other and run as separate oxygenation methods.

Thesis (Ph. D.)--Ohio State University, 2007.

Thesis (M.Sc.)(Plant Physiology))-University of Pretoria, 2005. / Includes summary Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (M.Ed.)--Kutztown State College, 1972. / Source: Masters Abstracts International, Volume: 45-06, page: 3033. Typescript. Includes bibliographical references (leaves 24-25)

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiii, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 70-73).

Pelargonium inquinans which belongs to the family Geraniaceae, is an essential oil yielding plant. P. inquinans was collected from two different sites in Grahamstown (wild) and Alice, at the University of Fort Hare botanical garden. Authentication of the plant was done by Dr. T. Dold at Schonland herbarium, and the voucher specimen being T01. This study is focused at determining the chemical constituents and biological properties of the essential oils of wild and cultivated P. inquinans across different seasons, as the plant grows throughout the year. Seasonal collection of wild and cultivated P. inquinans was achieved in a duration of 12 months. 32 essential oil samples of P. inquinans were obtained by extraction using hydro-distillation technique for 3-4 hours. The chemical composition of the essential oils was determined using GC/MS and GC/FID. Amongst the 32 essential oils only 4 samples wild ( fresh stem and leaf) and cultivated ( fresh stem and leaf) from summer season were evaluated for analgesic activity using acetic acid induced writhings and hot plate nociception models in mice, anti-inflammatory activity was determined on the egg albumin- induced rat paw oedema in rats. The results obtained from GC-MS revealed a total of 169 components obtained from the leafstem, fresh/dry wild and cultivated P. inquinans. These essential oils showed a great deal of chemotaxonomic variation and similarity in the major and minor components along the season. In spring season the essential oils of wild and cultivated P. inquinans had abundance of hydrogenated sesquiterpenes (20.6percent-66.7percent). The major components were found to be α-caryophyllene (9.1percent-26.8percent), p-xylene (23.3percent-27.5percent), β-caryophyllene (11.4percent-30.9percent), o-xylene (6.3percent-39.4percent), β-thujene (8.7percent), isocaryophyllene (13.9percent), isoborneol (14.2percent), β-myrcene (5.7percent), geranyl acetate (13.8percent), toluene (7.9percent), β-gurjunene (18.5percent), α-cadinene (15.8percent), β-farnesene (14.2percent), 3-carene (12.1percent) and camphene (9.0percent). In summer season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (50.3percent- 63.0percent), oxygenated monoterpenes (30.4percent) and hydrogenated monoterpenes (20.8percent- 61.0percent). The major components were found to be α-caryophyllene (12.3percent-25.8percent), β-caryophyllene (15.1percent- 31.7percent), trans-caryophyllene (10.3percent- 17.8percent), phytol (14.2percent- 20.2percent), camphor (46.5percent), sabinene (27.8percent), elemol (18.1percent), z3-hexenyl isobutyrate (16.3percent), limonene (12.1percent), menthone (12.1percent)< E.E-β-farnesene (14.7percent), palmitic acid (9.6percent), eugenol (9.4percent), cis- β-ocimene (8.7percent), α-terpineol (8.7percent), geranyl acetone (7.8percent), β- humulene (7.5percent). linoleic acid (7.4percent), trans-linalool oxide (7.4percent), β-bisabolene (7.1percent), cis- linalool oxide (7.1percent), ionone (6.9percent), caryophyllene oxide (6.9percent) and germacrene d (6.3percent). In autumn season the essential oils of wild and cultivated P. inquinans were found to be rich in hydrogenated sesquiterpenes (29.3percent- 65.2percent) and oxygenated sesquiterpenes (22.8percent- 31.4percent). The major components were found to be α-caryophyllene (15.5percent- 23.4percent), β-caryophyllene (15.2percent- 17.2percent), β-myrcene (7.7percent-13.8percent), β-humulene (8.7percent- 15.2percent), caryophyllene oxide (9.8- 16.2percent), trans- caryophyllene (16.7percent- 23.3percent), α-humulene (11.8percent- 18.6percent), linoleic acid (11.2percent), palmitic acid (10.4percent), phytol acetate (8.5percent), -longipinene (8.3percent) and citronellol (7.8percent). In winter season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (25.1percent- 48.6percent), oxygenated monoterpenes (47.6percent), oxygenated sesquiterpenes (22.2percent- 28.0percent). The major components were found to be β-caryophyllene (14.6percent- 23.0percent), α-caryophyllene (9.4percent- 18.0percent), trans- caryophyllene (12.2percent- 14.6percent), α-cedrene (26.2percent), germacrene –d-4-ol (16.8percent), 2,6-dihydroxyacetophenone (15.6percent), (+) epibicyclosesquiphellandrene (15.3percent), E-β- farnesene (13.0percent), β-phellandrene (11.7percent), 2-nitrophenol (9.5percent), palatinol (8.4percent), geranyl acetate (7.7percent) and linoleic acid (7.4percent). The oils from the wild and cultivated sources showed significant (p<0.05-0.001) decrease in number of writhes induced by the acetic acid compared to vehicle; caused significant (p<0.05-0.001) delay in reaction time on the hot plate at 60 and 90 min post-treatment and significantly (p<0.05-0.001) reduced oedema size caused by the egg albumin injection compared to the vehicle. The oils from the wild plant showed more potency compared to the cultivated. The essential oils of wild and cultivated P. inquinans showed qualitative, quantitative and chemotaxonomic variation with analgesic and anti-inflammatory activity. These essential oils need to be explored for further biological analysis because of the major components they contain.

Thesis (Ph.D.)--Mississippi State University. Department of Plant and Soil Sciences. / Title from title screen. Includes bibliographical references.