Aerial Seeds Research Articles

Reproductive strategies in the persistence of polymorph clover, an amphicarpic species

Amphicarpic plants produce aerial and subterranean fruits on the same plant. Trifolium polymorphum Poir. is an amphicarpic legume that also reproduces vegetatively by regrowing storage roots. Because of this, resource allocation information for different reproductive strategies is of great interest. In this study, the production of aerial and subterranean seeds and storage roots was evaluated in populations of T. polymorphum. The Pinheiro Machado and Eldorado do Sul populations produced on average the highest (165.50) and lowest (61.87) number of inflorescences per plant, respectively. Total aerial seed production did not differ between populations. Aerial flowers produced more seeds than subterranean flowers. There were positive correlations between number of inflorescences and total aerial seeds (r = 0.73), the number of subterranean legumes and total subterranean seeds (0.94) and between number and weight of storage roots (r = 0.83). Amphicarpy associated with vegetative reproduction is an important strategy for the persistence and increase frequency of T. polymorphum in the natural pastures of the Rio Grande do Sul, where intense grazing and trampling can destroy periodically the aerial part of the plants.

Subterranean and aerial seed production of southern threecornerjack (Emex australis)

AbstractSouthern threecornerjack (Emex australis Steinh.) produces both aerial seeds on the branches and subterranean seeds at the base of the plant crown approximately 1 to 2 cm underground. Prior research indicated that seeds buried at a depth of 1 cm have a much higher probability of germinating in the following season compared with seeds on the soil surface. The current research investigated the number of subterranean seeds produced per plant, timing of subterranean seed production, and germination requirements of subterranean seeds compared with aerial seeds. This research demonstrated that E. australis plants from multiple populations produced subterranean seeds beginning at the 4-leaf development stage, before the production of aerial seeds. Individual plants produced a maximum of 30 subterranean seeds. Germination of subterranean and aerial seeds following afterripening over the summer to autumn (December to May) fallow was similar, demonstrating that the different seed types had no differences in dormancy. Further, the subterranean seeds did not have the light requirement for germination observed in aerial seeds. Subterranean seeds had 22.2% and 24.3% germination in light and dark conditions, respectively, compared with aerial seeds, which had 26.9% germination in light conditions and 12.3% germination in the dark. Production of subterranean seeds was low, given that a mature E. australis plant may produce more than 1,100 aerial seeds, but the subterranean seeds formed earlier in plant development. Recommendations for postemergence herbicides are to spray E. australis at the 2- to 4-leaf stage of growth, yet some plants may have already produced mature subterranean seeds by this stage. Further research is required to determine the impact of subterranean seeds on population ecology.

Differences in seed dormancy and germination in amphicarpic legumes: manifold bet-hedging in space and time

Abstract Aims Dispersal through space or time via dormancy is one of the primary processes whereby organisms can influence the environment they experience. In plants, strong evolutionary correlations are expected between the two kinds of dispersal because both are performed by the seeds and play comparable adaptive roles. In this paper, we investigated these evolutionary correlations using amphicarpic plants, which simultaneously produce aerial seeds with high spatial dispersal propensity and subterranean seeds that do not disperse. Methods We investigated the variation in dormancy and germination in aerial and subterranean seeds of two amphicarpic legumes (Vicia amphicarpa L. and Lathyrus amphicarpos L.) and two closely related homocarpic taxa (Vicia sativa L. and Lathyrus cicera L.) by estimating germination percentages following different combinations of dormancy breaking treatments (i.e. dry after-ripening, cold stratification and physical scarification). Important Findings Our results showed complex interactions between spatial and temporal dispersal. Right after dispersal, aerial seeds were more dormant than their subterranean counterparts, but this trend reversed with after-ripening, as seeds developed physical dormancy. Seeds of homocarpic plants germinated at higher percentages than those of their amphicarpic congeners and lost dormancy homogeneously with after-ripening. Conversely, amphicarpic seeds exhibited varied dormancy strategies modulated by both physiological and physical dormancy. These are expected to increase variation in emergence timing, providing multiple levels of diversifying bet-hedging. This strategy might be adaptive under highly unpredictable conditions by enabling plants to rely on historically favorable sites in good seasons without preventing spatial and temporal migration.

Bioassay-guided Isolation of Flavonoids from Caesalpinia bonduc (L.) Roxb. and Evaluation of Their Cytotoxicity.

Cancer is one of the most important causes of death all around the world. Screening plants and their secondary metabolites as cytotoxic agents is one of the common methods for identifying new compounds used in chemotherapy and inhibition cancer process. Caesalpinia bonduc (L.) Roxb. from the Fabaceae family was used for improving wound, fever, tumor, hydrocele, hernia, smallpox, toothache, inflammation, and as astringent, anthelmintic, antidiabetic, and antimalarial agent in traditional medicine. A bioassay-guided study of this species led to the isolation of three flavonoids. At first, the cytotoxicity of methanol extract of aerial parts (leaves and stems), seeds, and legumes of this plant was tested against MCF-7 and PC-3 by MTT assay. The methanol extract of legumes showed better inhibitory activities (IC50 < 500 µg/mL). As a result, this extract was selected for fractionation. In the next step, the ethyl acetate (EtOAc) fraction was selected for phytochemical analysis based on the inhibitory activity (IC50 = 170 ± 0.9 µg/mL). In this way, total phenol content (625 ± 7.2 GAE/g extract) and antioxidant activity (IC50 = 6.1 ± 0.3 µg/mL) was compared by BHT (IC50 = 13.5 ± 0.7 µg/mL). Finally, three compounds including, quercetin-3-methyl ether (1), kaempferol (2), and kaempferol-3-O-α-L-rhamnopyranosyl-1→2)-β-D-xylopyranoside (3) were isolated from EtOAc fraction, and all isolated compounds were tested for their cytotoxicity and compound 1 showed better inhibitory activity than other two compounds. This study suggests that Caesalpinia bonduc could be considered for further investigations as a natural source of biological compounds.

Produção de sementes em Trifolium polymorphum e T. argentinense em ambiente protegido

Trifolium polymorphum e T. argentinense (Leguminosae) são duas espécies forrageiras anficárpicas nativas das pastagens naturais da metade sul do Rio Grande do Sul, no sul do Brasil. As informações a cerca da produção de sementes em ambas espécies são escassas. No presente trabalho nós avaliamos o número de inflorescências e a produção de sementes aéreas em T. polymorphum e T. argentinense em ambiente protegido e sem acesso de polinizadores. As plantas de T. polymorphum produziram significativamente mais inflorescências e sementes (63,15 e 8,94) que aquelas de T. argentinense (24,84 e 1,05), respectivamente. A baixa produção de sementes em ambiente protegido e sem acesso a polinizadores sugere a necessidade de estimulação mecânica para assegurar polinização, normalmente realizada por insetos, para formar sementes. Essas informações podem ser usadas para planejar futuros experimentos onde T. polymorphum e T. argentinense tenham livre acesso a polinizadores para obtenção de uma maior produção de sementes.

Amphicarpic plants: definition, ecology, geographic distribution, systematics, life history, evolution and use in agriculture.

ABSTRACTAlthough most plants produce all of their fruits (seeds) aboveground, amphicarpic species produce fruits (seeds) both above‐ and belowground. Our primary aims were to determine the number of reported amphicarpic species and their taxonomic, geographic, life form and phylogenetic distribution, to evaluate differences in the life history of plants derived from aerial and subterranean seeds, to discuss the ecological and evolutionary significance of amphicarpy, to explore the use of amphicarpic plants in agriculture, and to suggest future research directions for studies on amphicarpy. Amphicarpy occurs in at least 67 herbaceous species (31 in Fabaceae) in 39 genera and 13 families of angiosperms distributed in various geographical regions of the world and in various habitats. Seeds from aerial and subterranean fruits differ in size/mass, degree of dormancy, dispersal and ability to form a persistent seed bank, with aerial seeds generally being smaller, more dormant and more likely to be dispersed and to form a seed bank than subterranean seeds. In addition, plants produced by aerial and subterranean seeds may differ in survival and growth, competitive ability and biomass allocation to reproduction. Amphicarpic plants may exhibit a high degree of plasticity during reproduction. Subterranean fruits are usually formed earlier than aerial ones, and plants may produce only subterranean propagules under stressful environmental conditions. Differences in the life histories of plants from aerial and subterranean seeds may be an adaptive bet‐hedging strategy.

Trifolium polymorphum: an amphicarpic species with an interesting reproductive biology

An interesting aspect of the biology of Trifolium polymorphum, an endemic species of the natural pastures of Rio Grande do Sul State in Brazil, is that it is amphicarpic. Amphicarpy is a fascinating reproductive strategy in which aerial and subterranean seeds are produced by the same plant. We evaluated the number, size and weight of aerial and subterranean seeds of two populations (Bage and Santana do Livramento) of T. polymorphum which have grown from the regrowth of storage roots and in the absence of herbivory. Aerial flowers produced more seeds than subterranean flowers, about 14 times in the Santana do Livramento population and nine times in the Bage population. However subterranean seeds were heavier than aerial seeds. We suggest that in the natural pastures of Rio Grande do Sul, where intense grazing and trampling can periodically destroy the aerial part of the plants, the occasional formation of subterranean seeds in T. polymorphum provides an alternative safety system in terms of population persistence. Although amphicarpic, T. polymorphum invests early in asexual reproduction through the production of storage roots, which favors the persistence in unfavorable habitats for sexual reproduction, and thus plants may persist vegetatively year after year without the need of regeneration by seeds.

Effects of light intensity and plant density on growth and reproduction of the amphicarpic annual Persicaria thunbergii

To understand the advantages of amphicarpy in the early life history of Persicaria thunbergii, we compared plants from aerial seeds (AS) and subterranean seeds (SS) in two experiments using mesocosms. In full light, the growth of AS plants (75.5±10.8g/plant) and SS plants (80.2±9.6g/plant) was similar. However, in shade, SS plants (81.1±8.5g/plant) grew significantly more than did AS plants (40.3±8.5g/plant). SS plants produced more subterranean seeds in shade than they did in full light. An experiment comparing three seedling densities revealed no effect on total biomass of SS plants or AS plants, but the relative biomass of seeds produced by SS plants (12.6%) was higher than that produced by AS plants (6.4%). These traits of SS seedlings were more advantageous when competition for light was intensified as seedlings density increased. We suggest that SS plants play a key role in population formation in mature communities with dense canopies.

Effect of seed morph and light level on growth and reproduction of the amphicarpic plant Amphicarpaea edgeworthii (Fabaceae)

Amphicarpic plants produce aerial and subterranean fruits on an individual plant, and these heteromorphic diaspores give rise to plants that differ in growth and ecology. Amphicarpaea edgeworthii is a summer annual amphicarpic species that grows over a range of light levels. We aimed to compare the response to shading intensity of plants of A. edgeworthii grown throughout their life cycle from aerial seeds (ASP) and from subterranean seeds (SSP). We hypothesized that vegetative and reproductive growth of plants from ASP and SSP respond differently to light. Plants were grown from ASP and SSP under 0, 46, 71 and 90% shading intensities. With plant height as a covariate, vegetative biomass of ASP and SSP did not differ. Leaf area and seed production of SSP were greater and internode length less than they were for ASP in all shading intensities. Aerial and subterranean seed yield, seed mass and number for both ASP and SSP were highest in full light. Aerial seed yield was affected more than subterranean seed yield by shading intensity. The growth and reproductive responses of ASP and SSP of A. edgeworthii may be adaptive to the range of low to high light environments in which this species grows.

Effects of nutrient availability on the amphicarpic traits of Persicaria thunbergii

Environmental factors affecting the expression of amphicarpic traits in Persicaria thunbergii are not well studied. We thus performed to investigate the effects of nutrients on the amphicarpic traits of P. thunbergii in a mesocosm experiment. Three nutrient levels were applied using different intervals between fertilization: no fertilization (low nutrient), fertilization at eight-week intervals (medium), and at four-week intervals (high). We compared the relative stem length growth rates (RGRST) and biomass allocation of seedlings from aerial seeds (SA) and subterranean seeds (SS), and then investigated the flowering time and the seed production traits of P. thunbergii according to nutrient level. The results showed that RGRST, biomass allocation and total biomass were not different between SA and SS at all levels. Aerial flowering started earlier than subterranean flowering, in contrast to other amphicarpic plants. Subterranean seed allocation and the number of subterranean seeds were stable regardless of nutrient levels whereas aerial seed allocation decreased with increasing nutrient level. The number of aerial seeds per biomass with low nutrient was significantly higher than that at other levels. P. thunbergii showed a different trait of seed production: subterranean seeds appeared to play a role in retaining the mother-site while aerial seeds can escape the site conditions at low nutrient levels. In conclusion, the reproductive strategy of P. thunbergii on aerial propagule was changeable but not subterranean propagule under various nutrient conditions. SA and SS were similar about growth responses. Those characteristics would increase survivability of P. thunbergii. Evolutionary drivers might explain the differences of life-history strategies in flowering time between the aquatic P. thunbergii and other arid amphicarpic plants.

Expression of amphicarpy in Vigna lanceolata morphotypes and their hybrids and implications for cultivar development

Amphicarpy is an adaptation that enhances persistence under various environmental stresses, including heavy grazing, through the production of both aerial and underground seeds on the same plant. The trait occurs in several Australian endemic tropical herbaceous legumes, including Vigna lanceolata. The objective of the current research was to compare aerial and underground reproductive structures in six amphicarpic morphotypes of V. lanceolata (four perennials and two annuals), and in hybrids among these morphotypes and also with a seventh, non-amphicarpic perennial morphotype. The aim was to establish how easily the trait might be manipulated in a breeding program to develop improved amphicarpic cultivars, for ley and forage purposes. In the four amphicarpic perennials, the underground fruiting structures formed on leafless underground stems or rhizomes, and in all four, amphicarpy was habitual, i.e. individual plants routinely developed both aerial and underground fruiting structures. In the two annuals, the underground fruiting structures developed on specialised axillary geotropic stems that arose along the prostrate aerial stems and penetrated the soil or leaf litter. One of the annuals exhibited habitual amphicarpy, whereas the other was opportunistic, in that the underground fruiting structures developed only where aerial stems became covered with soil or leaf litter. F1 hybrids between the two annual morphotypes exhibited habitual amphicarpy, indicating dominance of habitual over opportunistic amphicarpy. F1 hybrids between the four perennial amphicarpic morphotypes were all amphicarpic, reflecting the similar expression of the trait in these forms. By contrast, when these four were crossed with the non-amphicarpic perennial, none of the viable F1 hybrids exhibited amphicarpy, suggesting dominance for non-expression. Many of the perennial F1 hybrids were self-sterile, but in the hybrids that were at least partially fertile, many more geocarpic than aerial seeds were produced, raising the possibility that in the wild, amphicarpy may facilitate the persistence of chance natural outcrosses that might otherwise not survive. The results suggested that it would be feasible to develop amphicarpic annual and amphicarpic perennial cultivars for, respectively, ley and forage purposes.

Lack of divergence in seed ecology of two Amphicarpaea (Fabaceae) species disjunct between eastern Asia and eastern North America.

Many congeneric species are disjunct between eastern Asia and eastern North America. No previous study has compared the seed biology of closely related disjunct taxa of legumes or of a diaspore-heteromorphic species. Our objective was to compare seed dormancy in two such sister species in the genus Amphicarpaea (Fabaceae). We investigated the ecology and ecophysiology of aerial and subterranean seeds of the amphicarpic species Amphicarpaea edgeworthii from China and compared the results to those published for its sister species A. bracteata from eastern North America. The seed coat of aerial seeds of A. edgeworthii is well developed, whereas the seed coat of subterranean seeds is not. Aerial seeds have combinational dormancy (physical dormancy [PY] + physiological dormancy [PD]) broken by scarification followed by cold stratification or by after-ripening and scarification; whereas subterranean seeds have PD broken by cold stratification. Aerial seeds formed a persistent soil seed bank, and subterranean seeds a transient soil seed bank. Aerial seeds of A. bracteata also have PY+PD and subterranean seeds PD. Subterranean seeds of both species are desiccation intolerant. Dormancy in neither aerial nor subterranean seeds of both species has diverged over geological time. Compared to subterranean seeds, aerial seeds of both species dispersed over longer distances. Seed dispersal ability and degree of dormancy of neither species fits the high-risk/low-risk (H-H/L-L) strategy found in many diaspore-dimorphic species. Rather, both species have an H-L/L-H strategy for these two life history traits.

Advantages of amphicarpy of Persicaria thunbergii in the early life history

Persicaria thunbergii is an annual Polygonaceae herb and an amphicarpic plant. To understand the advantages of amphicarpy in the early life history of P. thunbergii, we compared aerial seeds (AS) and subterranean seeds (SS) and seedlings in terms of seed size, weight, germination rate, and seedling stress response under both shaded and water-logged conditions in a mesocosm experiment. The major and minor axes of the SS were 22% and 17% longer than those of the AS, respectively. The SS were 37% heavier than the AS. Additionally, the germination rate of SS was higher than that of AS during the early phase (first germination test) and under water-logged conditions (second germination test). Average stem length of seedlings from SS in the control group was 41% longer than that of seedlings from AS. SS had greater leaf number, root length, and overall dry weight than those of AS. The SS in the shaded group had 34% longer stems and 99% wider leaf area than those of AS. Moreover, stem length of SS increased more rapidly than that of AS to escape flooding conditions. We conclude that larger and buried SS may be advantageous to re-occupy the mother site after adverse conditions, whereas lighter and AS may disperse more easily because the seeds probably disperse in water.

Flooding effects on seed production of the amphicarpic plant Persicaria thunbergii

The purpose of the study was to investigate the effects of flooding on amphicarpic seed production of Persicaria thunbergii using a mesocosm experiment. The plants were subjected to 2 weeks of inundation corresponding to plant height in June and August to assess the effect of simple flood timing. To mimic severe damage caused by flooding, 50% of the leaves were removed and the plants were shaded for 1 week. The results showed that simple flooding during early vegetative growth and the late vegetative growth had no effects on production of amphicarpic seeds or vegetative parts. The amphicarpic seeds of P. thunbergii did not show any changes under inundation levels reaching plant height. However, flooding with damage during late vegetative growth tended to decrease the production of subterranean seeds and total plant mass. In particular, production and single seed weight of subterranean seeds decreased significantly with a reduction in biomass under a strong disturbance. Subterranean seeds were formed later than aerial seeds. We suggest that unlike other amphicarpic plants, subterranean seeds of P. thunbergii are vulnerable to poor environmental conditions and the plant reduces production of subterranean seeds when time and energy do not permit. Amphicarpy, as an evolutionary adaptation by P. thunbergii, seems to have different ecological significance from that of other amphicarpic plants.

Reproductive versatility in legumes: the case of amphicarpy in Trifolium polymorphum

Amphicarpy is a fascinating reproductive strategy, defined as fruit produced both below the soil surface and as aerial fruit on the same plant. Trifolium polymorphum is a grassland species subject to herbivory that combines amphicarpy with vegetative reproduction through stolons. Underground flowers have been described as obligate autogamous and aerial ones as self-compatible allogamous, with aerial floral traits favouring cross-pollination. In the present work we performed different pollination treatments on aerial flowers to analyse rates of pollen tube development and offspring fitness, measured as fruit set, seed production and germination percentage. This last variable was compared to that of seeds produced underground. No significant differences were found between fruit set in self- and cross-pollinations. Seed production was higher in self-pollinations, which is consistent with the higher rate of pollen tube development observed in self-crosses. Spontaneous self-pollination is limited in aerial flowers; thus pollen transfer by means of a vector is required even within the same flower. Germination tests showed that aerial seeds produced after self- and cross-pollination did not differ in fitness, but underground seeds had higher germination percentage than aerial ones. Thus, we conclude that T. polymorphum has a mixed mating system. In grasslands with heavy grazing pressure, clonal propagation and underground seed production ensure persistence in the field. An intermediate level of selfing in aerial flowers ensures offspring, but morphological (herkogamy) and functional (dicogamy) floral traits maintain a window to incorporate genetic variability, allowing the species to tolerate temporal and spatial pressures.

Amphicarpy in Trifolium argentinense: morphological characterisation, seed production, reproductive behaviour and life strategy

Trifolium argentinense Speg. is an amphicarpic species that occurs naturally in native pastures of Rio Grande do Sul, southern Brazil. Amphicarpy is a rare mode of reproduction in which aerial and subterranean seeds are produced by the same individual. In the present paper, we compare morphology, anther number, pollen viability, seed production and mode of reproduction of T. argentinense flowers, and comment on the life strategy of the species. Plants grown from aerial seeds and from the regrowth of storage roots of aerial plants had longer stolons and a larger plant diameter than did those grown from subterranean plants. Plants grown from seeds were also taller than plants grown from storage roots. More resources were allocated to subterranean reproduction in plants of subterranean origin than in those of aerial origin. Aerial flowers produced more seeds, presented more anthers and produced more pollen grains than did the subterranean ones. T. argentinense is a versatile species, self- and cross-pollinated, consistent with the values of high polymorphism information content. T. argentinense adopts the ‘pessimistic strategy’ (early allocation of energy to large subterranean propagules), common in amphicarpic species when growing in disturbed habitats, such as the native pastures of Rio Grande do Sul, where intense grazing and trampling, as well as long seasonal dry spells, may periodically destroy the aerial plants, thus assuring survival by germination of subterranean seeds and regrowth of storage roots.

Antiulcerogenic and antibacterial activities of Apium graveolens essential oil and extract

This study investigates the antiulcerogenic and antibacterial activities of Apium graveolens extracts. The antiulcerogenic activity was evaluated in rats by the HCl/EtOH method. Inhibition of gastric lesions by A. graveolens extracts was dose-dependent for both aerial part (53–76%) and seeds (51–95%). The methanolic extract as well as the aqueous extracts used at 300 mg kg−1 dose exhibited a highly significant inhibition of gastric lesions (91% and 95%, respectively) which was similar to that induced by omeprazole (94%). Essential oil and aqueous extract prepared from the aerial parts of A. graveolens were tested to determine their antibacterial activity using the paper disc-diffusion method, the minimal inhibitory concentration and the minimal bactericidal concentration. Essential oil of A. graveolens was strongly inhibitory against Escherichia coli and moderately inhibitory against Pseudomonas aeruginosa and Staphylococcus aureus. The chemical composition of the volatile oil was investigated by gas chromatography analysis. The major components identified were β-pinene, camphene, cumene, limonene, α-thuyene, α-pinene, β-phellendrene, p-cymene, γ-terpinene, sabinene and terpinolene.

Evaluation of Factors That Influence Benghal Dayflower (Commelina benghalensis) Seed Germination and Emergence

A perennial species in its native range of Asia and Africa, Benghal dayflower in North America establishes annually from seed. This species has the unique ability to produce aerial and subterranean flowers and seeds. Information on how various environmental factors affect Benghal dayflower aerial and subterranean seed germination and emergence in the United States is lacking. Studies were conducted to determine the effect of temperature, planting depth, salt concentration, and pre-emergence herbicides on germination or emergence of aerial and subterranean Benghal dayflower seed. Maximum aerial seed germination occurred at 30 C, whereas maximum subterranean seed germination occurred at 30 and 35 C. Germination at 40 C was delayed relative to optimum temperatures. The seed coats in this study were mechanically disrupted to evaluate the response of seeds to temperature in the absence of physical dormancy. The physical dormancy imposed by the seed coat could require additional study. Benghal dayflower was not tolerant to ≥ 10 mM NaCl, indicating that this exotic species is not likely to become problematic in brackish marshes and wetlands of coastal plain regions. There was an inverse linear response of Benghal dayflower emergence and planting depth, with no emergence occurring at a planting depth of 12 cm. A field survey of Benghal dayflower emergence revealed that 42% of plants established from a depth of 1 cm in the soil profile, with 7 cm being the maximum depth from which seedlings plants could emerge. This suggests that PRE herbicides must remain in the relatively shallow depths of the soil profile to maximize control of germinating seedlings. Subterranean seeds were less sensitive than aerial seeds toS-metolachlor, the primary means of controlling this species in cotton. There were no differences between the germination of aerial and subterranean seed in response to treatment with diclosulam.

Lipids and flavolignans from Silybum marianum

Lipids from the air-dried aerial part (AP) and seeds of Silybum marianum (L.) Gaerth. (Asteraceae) were studied. The class and fatty acid compositions of neutral lipids (AP, seeds) and glyco- and phospholipids (AP) were determined. Neutral lipids (NL) with a complicated set of lipophilic components, mainly triterpenols, sterols, and their esters predominated in the AP. The fatty acids of the AP were dominated by 16:0, 18:2 (glycolipids), and 18:3 (neutral lipids, phospholipids); of seed NL, by 18:2 and 18:1. The content and composition of flavolignans isolated from defatted seeds and the content of total protein in the meal were found.

Systematic Revision of the Genus Pancratium L. (Amaryllidaceae) in Egypt with a New Addition

In Egypt, taxonomic aspects of the genus Pancratium L. (Amaryllidaceae, Pancratieae) were thoroughly studied to point out the most reliable characters for taxon delimitation. Here, we base our species on both geographical and morphological features. The detailed taxonomic revision of genus Pancratium is based on field studies and the examination of representative specimens together with the authentic types deposited in the major herbaria of Egypt and Kew. Variations in the aerial scape, spathe, perianth, corona-teeth, pistil, stamens, capsules and seeds, as well as those of leaf base and leaf orientation are good markers to separate the different species. As a result, five species are recognized, including P. trianthum as a new record to the flora of Egypt. It is restricted to the south-eastern corner of Egypt (Gebel Elba region) and being unique in possessing solitary spathe and long attenuate leaf base. A specific key and descriptions are given with typifications.