Evergreen Shrub Research Articles

Transcriptome Analysis Reveals the Crucial Role of Phenylalanine Ammonia-Lyase in Low Temperature Response in Ammopiptanthus mongolicus.

Background: Ammopiptanthus mongolicus is a rare temperate evergreen shrub with high tolerance to low temperature, and understanding the related gene expression regulatory network can help advance research on the mechanisms of plant tolerance to abiotic stress. Methods: Here, time-course transcriptome analysis was applied to investigate the gene expression network in A. mongolicus under low temperature stress. Results: A total of 12,606 differentially expressed genes (DEGs) were identified at four time-points during low temperature stress treatment, and multiple pathways, such as plant hormones, secondary metabolism, and cell membranes, were significantly enriched in the DEGs. Trend analysis found that the expression level of genes in cluster 19 continued to upregulate under low temperatures, and the genes in cluster 19 were significantly enriched in plant hormone signaling and secondary metabolic pathways. Based on the transcriptome data, the expression profiles of the genes in abscisic acid, salicylic acid, and flavonoid metabolic pathways were analyzed. It was found that biosynthesis of abscisic acid and flavonoids may play crucial roles in the response to low temperature stress. Furthermore, members of the phenylalanine ammonia-lyase (PAL) family in A. mongolicus were systematically identified and their structures and evolution were characterized. Analysis of cis-acting elements showed that the PAL genes in A. mongolicus were closely related to abiotic stress response. Expression pattern analysis showed that PAL genes responded to various environmental stresses, such as low temperature, supporting their involvement in the low temperature response in A. mongolicus. Conclusions: Our study provides important data for understanding the mechanisms of tolerance to low temperatures in A. mongolicus.

Qualitative Analysis of Daphnane Diterpenoids in Various Parts of Daphne pontica L. by UHPLC-Q-Exactive-Orbitrap MS.

Daphne pontica L. is an evergreen shrub that is recorded as an anti-diarrheic plant in Turkish folk medicine. Previous studies on D. pontica have reported, albeit slightly, the isolation of daphnane diterpenoids, but no systematic phytochemical analysis of daphnane diterpenoids has been conducted. This study aimed to comprehensively investigate daphnane diterpenoids in the extracts from the different parts (stems, leaves, and fruits) of D. pontica. An ultra-high-performance liquid chromatography coupled with Q-Exactive hybrid quadrupole Orbitrap mass spectrometer (UHPLC-Q-Exactive-Orbitrap MS) was used for the qualitative analysis of D. pontica. The stems, leaves, and fruits of D. pontica were extracted with diethyl ether. Each extract was then pretreated by a solid phase extraction cartridge and subjected to LC-MS/MS analysis. Detected daphnane diterpenoids were tentatively identified by comparison with an in-house daphnane library, and their chemical structures were estimated in detail by MS/MS fragmentation evaluation. A total of 33 kinds of daphnanes were identified from the different parts of D. pontica, and were classified into three subtypes: daphnane orthoester, polyhydroxy daphnane, and macrocyclic daphnane orthoester. Among them, six daphnanes were postulated to be previously unreported compounds based on MS/MS fragmentation elucidation. Furthermore, the three plant parts showed similar daphnane diterpenoid profiles, with the stems containing the most abundant daphnane diterpenoids. This is the first study to perform qualitative analysis of daphnane diterpenoids systematically and comprehensively in different parts of D. pontica. The results revealed that D. pontica is a plant resource rich in a variety of daphnane diterpenoids.

A Review on Medicinal Properties of Lantana Camara Linn

India has a long heritage of using plant-based knowledge in health care. Few natural medications in India have been thoroughly researched despite their abundance. Lantana camara is an evergreen shrub that grows throughout India. Traditionally, it has been used to heal a variety of diseases, and these claims are confirmed by scientific evidence. Various publications have described the phytoconstituents found in all sections of Lantana camara. Over the past few decades, scientists and researchers worldwide have extensively examined the chemical composition and biological pharmacological activity of the entire L. Camara plant. These results suggest that Lantana camara has therapeutic promise in modern medicine and could be a viable drug discovery target. This article examines the pharmacological properties and toxicity of Lantana camara .

First De Novo genome assembly and characterization of Gaultheria prostrata.

Gaultheria Kalm ex L. (Ericaceae), a type of evergreen shrub, known as a natural source of methyl salicylate, possesses rich germplasm resources, strong habitat adaptability, significant ornamental value, and noteworthy pharmacological activities. However, due to the paucity of whole genomic information, genetically deep research in these areas remains limited. Consequently, we intend to obtain genome data through high-throughput sequencing, gene annotation, flow cytometry, transcription factors prediction and genetic marker analysis for a representative species of this genus, with Gaultheria prostrata selected for our study. In this study, we preliminarily obtained the genome of G. prostrata through next-generation sequencing methods. Utilizing 47.94 Gb of high-quality sequence data (108.95× coverage), assembled into 114,436 scaffolds, with an N50 length of 33,667 bp. The genome size assembled by SOAPdenovo, approximately 417 Mb, corresponded closely to predictions by flow cytometry (440 Mb) and k-mer analysis (447 Mb). The genome integrity was evaluated using BUSCO with 91%. The heterozygosity ratio was 0.159%, the GC content was 38.85%, and the repetitive regions encompassed over 34.6% of the genome. A total of 26,497 protein-coding genes have been predicted and annotated across Nr, Swissprot, GO, KEGG, and Pfam databases. Among these, 14,377 and 2,387 genes received functional annotation in Nr and Swissprot, respectively; 21,895, 24,424, and 22,330 genes were similarly annotated in GO, KEGG, and Pfam. Moreover, A total of 279,785 SSRs were identified and 345,270 primers for these SSRs were designed. Within the various nucleotide types of SSRs, AG/CT and AAG/CTT constituted the predominant dinucleotide and trinucleotide repeat types in G. prostrata. In addition, 1,395 transcription factors (TFs) from 75 TF families, 462 transcription regulators (TRs) from 33 TR families and 840 protein kinase (PKs) from 118 PK families were identified in this genome. We also performed phylogenetic analyses of G. prostrata and related species, including estimation of divergence times and expansion and contraction analyses, followed by positive selection analyses of orthologous gene pairs of G. prostrata and its close relative Vaccinium corymbosum. These results provide a reference for in-depth study of genus Gaultheria, contributing to future functional and comparative genomics analyses and providing supporting data for the development of molecular markers.

First Report of Robbsia andropogonis Causing Bacterial Blight of Danae racemosa (Poet’s Laurel) in a Virginia Ornamental Nursery

Danae racemosa (L.) Moench (Asparagaceae, Monocots) is a shade-tolerant, evergreen shrub native to Persia. On 02 July 2024, at an ornamental nursery in Hanover County, Virginia, 300 plants in 7.6 L containers were observed with blotchy, rust-colored, water-soaked lesions on the cladophylls and stems. Heavy bacterial streaming was observed from the lesions under the microscope, and sterilized tissue was cultured on King's B medium at 22 ± 2°C. After 72 hours, cream-colored colonies developed that were oxidase and gram negative and did not produce fluorescent pigments on King B medium. PCR amplification and sequencing of the partial 16S rRNA, gyrB, and rpoD genes from strain GS24-DSB16 were deposited into the NCBI Genbank database (PQ181184, PQ182786, PQ182787). Based on the morphological and molecular characteristics, the causal agent was identified as Robbsia andropogonis (Smith) Lopes-Santos et al. Koch’s postulates were fulfilled by wounding twenty cladophylls from each plant with a sterile needle, and 10 μl of an aqueous bacterial suspension was pipetted on each wound. R. andropogonis has a wide global distribution from a host range spanning >15 plant families, including maize, sorghum, sugarcane, citrus, coffee, and carnation. To the authors knowledge, this is the first report of the bacteria causing blight on D. racemosa, and the first host in Asparagaceae.

Profitability and Cost Estimates for Producing Tropical Hibiscus in South Florida

Tropical hibiscus (Hibiscus rosa-sinensis) is a bushy evergreen shrub or small tree native to the temperate regions of Asia and an economically significant crop in Florida. According to the 2017 Census of Agriculture, the market value of the ornamental industry in Miami-Dade County was $697 million, and approximately 25% of the production was in hibiscus. Demand for the cultivation of plants with minimal pesticides is rising due to concerns about potential adverse environmental and health effects. Integrated pest management, or IPM, is an alternative to conventional pesticide application. A broad-based approach, it integrates both chemical and non-chemical practices for sustainable control of pests. To help growers and other stakeholders determine the best approach to changing demands for pesticide management, this publication estimates the costs and returns of producing tropical hibiscus on an established nursery in south Florida using both traditional and IPM methods.

Chromosome-scale genome assembly of acerola (Malpighia emarginata DC.).

Acerola (Malpighia emarginata DC.) is a tropical evergreen shrub that produces vitamin C-rich fruits. Increasing fruit nutrition is one of the main targets of acerola breeding programs. Genomic tools have been shown to accelerate plant breeding even in fruiting tree species, which generally have a long-life cycle; however, the availability of genomic resources in acerola, so far, has been limited. In this study, as a first step toward developing an efficient breeding technology for acerola, we established a chromosome-scale genome assembly of acerola using high-fidelity long-read sequencing and genetic mapping. The resultant assembly comprises 10 chromosome-scale sequences that span a physical distance of 1,032.5 Mb and contain 35,892 predicted genes. Phylogenetic analysis of genome-wide SNPs in 60 acerola breeding materials revealed 3 distinct genetic groups. Overall, the genomic resource of acerola developed in this study, including its genome and gene sequences, genetic map, and phylogenetic relationship among breeding materials, will not only be useful for acerola breeding but will also facilitate genomic and genetic studies on acerola and related species.

Phytochemical investigation and spectral characterization of isolated compounds from Pyracantha crenulata (D. Don) M. Roem (syn. Crataegus crenulata Roxb) leaves: evaluation of antioxidant activity and molecular docking analysis

Pyracantha crenulata (D. Don) M. Roem (syn. Crataegus crenulata Roxb.) is an evergreen shrub in the Rosaceae family, notable for its chemical diversity and biological potential. This study isolates and characterises six compounds (Cc-1 to Cc-6), including four new ones, using repeated column chromatography. Structural elucidation employed IR, UV-vis, 1H and 13 C NMR, and mass spectrometry. The DPPH assay was used to test the antioxidant activity in vitro. Compounds Cc-4, Cc-2, Cc-1, and Cc-5 had IC50 values of 15.734 μg/ml, 51.422 μg/ml, 62.864 μg/ml, and 71.622 μg/ml, in that order. Quantitative phytochemical analysis revealed flavonoid content (22.81 mg/g), tannin content (385.15 mg/g), and total phenolic content (128.78 mg/g). Human cyclin-dependent kinase 2 (CDK2) (PDB ID: 1hck) docked with compound Cc-4, which demonstrated strong antioxidant activity and revealed significant non-bonding interactions. The pkCSM and SwissADME analyses suggested promising drug-like properties for Cc-4, supported by BOILED-Egg diagrams highlighting its therapeutic potential.

Pittosporum tobira 'Wheeleri' Wheeler's Dwarf Pittosporum

This document provides an overview of Wheeler’s dwarf pittosporum, an evergreen shrub known for its compact, rounded form and dark green foliage. It details the plant’s characteristics, including its moderate growth rate, dense texture, and specific leaf and flower attributes. The document also covers the plant’s preferred growing conditions, such as its need for well-drained soil and partial to full sun exposure, and highlights its uses in landscaping, particularly in coastal areas. Additionally, it notes the plant’s susceptibility to certain pests and diseases, emphasizing the importance of proper maintenance and care. Original publication date October 1999.

Estimating the Concentration of Heavy Metals in Oleander/Pink and white Oleander Plants

Oleander is a large ornamental evergreen shrub that may grow 20–25 ft in height. During the summer months’ large clusters of white, pink, red, or yellow (yellow oleander) flowers appear at the ends of the branches. All parts of the plant contain cardiac glycosides. Oleander is a common source of serious plant poisoning. In South Asia, particularly Sri Lanka, also present in Libya desert and some house gardens with white and pink types, oleander has become a notorious method of suicide. Toxicity is largely characterized by gastrointestinal symptoms and cardiac abnormalities. Tachy or bradydysthythmias may be present in addition to slowed conduction and heart block. Hyperkalemia is common and correlates with severity of poisoning. A specific antidote—digoxin-specific fragment antigen-binding region (Fab region)- is available. In Mediterranean climates oleanders can be expected to bloom from April through October, with the heaviest bloom usually occurring between May and June. Free-flowering varieties like 'Petite Salmon' or 'Mont Blanc' require no period of rest and can flower continuously throughout the year if the weather remains warm. The exact nature of plant poisoning varies from region to region, but certain plants are almost ubiquitous in distribution and among these, Oleander is a garden plant that features in many homes. Incidents of poisoning from these plants are therefore not uncommon and may be the result of accidental exposure or deliberate, suicidal ingestion of the toxic parts. An attempt has been made to review the management principles with regard to toxicity of these plants and survey the literature in order to highlight current concepts in the treatment of poisoning resulting from both plants. Ingestion of its seeds results in a clinical picture similar to digoxin toxicity. It contains cardiac glycosides that are toxic to cardiac myocytes and autonomic system. Cardiac glycosides of oleander cause poisoning by inhibiting plasmalemmal Na+/K+-ATPase. Results: The poisoning effects of plant or their active alkaloids induced infiltration of cells with hemorrhage and sever negative changes in the lung, induce lesions, and infiltration of inflammatory cells into the portal spaces with scattered necrosis of hepatocytes in the liver, cardiac toxicity of the plant in the heart were included, induced varying degrees of hemorrhage, myocardial degeneration, and necrosis. It also induced arrhythmia, sinus bradycardia, and prolonged P-R interval in electrocardiographic records. Conclusions: The toxic effects of N. oleander are mostly related to its inhibitory effects on the Naþ-Kþ ATPase pump in the cellular membrane. However, the exact molecular mechanism involved in the toxicity of N. oleander is not clear.

Phytochemical and Pharmacological Profile of Plants from Genus Buxus: A Review

Buxus is an evergreen shrub of the Buxaceae family. A comprehensive survey of the literature has been conducted, revealing that alkaloids are the predominant metabolites characterized by their noteworthy biological activities. Of particular interest are the alkaloids that have exhibited significant cytotoxic activity against various cell lines, including HL-60, SMMC-7721, A549, MCF- 7, SW480, ES2, and A2780 cell lines. CVB-D, buxbodine B, and buxmicrophyllines F can inhibit the growth of tumor cells and induce tumor cell apoptosis. This article reviews the chemical constituents, antitumor effect, and mechanism of Buxus alkaloids in recent years so as to provide a reference for its further development and utilization of medicinal plants of the genus Buxus.

Discosia brasiliensis causing Discosia leaf blight on tea plant (Camellia sinensis) in China

Tea (Camellia sinensis), a perennial evergreen shrub, is one of the most important cash crops in China. Tea leaves with symptoms of wilt disease was observed in Fengqing County, Lincang City, Yunnan Province, China. Large irregular jujube-red necrotic spots appeared on the leaves of tea plants, and the lesions with grayish white edge were accompanied by a certain degree of shrinkage. In the tea garden planting base, the natural disease incidence reached 40%–50 %, which significantly affects the yield of tea. One putative pathogen was isolated from three symptomatic tea plant leaves and was identified as Discosia brasiliensis using morphology and molecular phylogeny of multi-loci (ITS, LSU, tub, rpb2) sequence data. Using D. brasiliensis strains for artificial inoculation assay on the tea plant leaves, leaf atrophy symptom in leaves which is similar to those observed in the tea planting base, and the putative pathogen was re-isolated to fulfill Koch's postulates. This is the first report of wilt disease caused by Discosia brasiliensis in China.

1111. Melastoma candidum D.Don var. alessandrense S.Kobayashi: Melastomataceae

SummaryMelastoma candidum D.Don var. alessandrense S.Kobayashi is an evergreen shrub endemic to Kita‐iwoto Island, an oceanic volcanic island in the subtropical northwestern Pacific Ocean. Here we provide illustrations to show the morphological features of this species and demonstrate the unique natural environment which is its habitat, where few people in the world have ever been.

AmDEF2.7, a tandem duplicated defensin gene from Ammopiptanthus mongolicus, activated by AmWRKY14, enhances the tolerance of Arabidopsis to low temperature and osmotic stress

Ammopiptanthus mongolicus is an evergreen broad-leaved shrub growing in temperate regions. Plant defensins, a type of cysteine-rich small peptides, contribute to plant defense as antimicrobial peptides. In this study, we analyzed the evolution and expression patterns of the defensin gene family in A. mongolicus, and explored the function and regulatory mechanisms of the AmDEF2.7 gene in response to abiotic stress. Seven out of ten defensin genes had undergone segmental duplication and tandem duplication, especially, AmDEF2.6, AmDEF2.7, and AmDEF2.8, which were clustered on chromosome 9. The expression of multiple defensin genes was responsive to abiotic stress, with three defensin genes, including AmDEF2.7, showing significant induction during winter. Yeast expressing AmDEF2.7 gene exhibited increased resistance to freeze-thaw cycles and osmotic stress, while transgenic Arabidopsis overexpressing the AmDEF2.7 showed improved tolerance to both freezing and drought conditions. Furthermore, AmWRKY14 bound to the AmDEF2.7 gene promoter, and activated the expression of AmDEF2.7. These results highlighted the role of defensin AmDEF2.7 in the adaptation of A. mongolicus to temperate winter climate. This study expands our knowledge of plant defensin and provides support for clarifying the molecular mechanism of the adaptation of A. mongolicus to winter climate.

Chromosome-level genome assembly and annotation of Flueggea virosa (Phyllanthaceae)

Flueggea virosa (Roxb. ex Willd.) Royle, an evergreen shrub and small tree in the Phyllanthaceae family, holds significant potential in garden landscaping and pharmacological applications. However, the lack of genomic data has hindered further scientific understanding of its horticultural and medicinal values. In this study, we have assembled a haplotype-resolved genome of F. virosa for the first time. The two haploid genomes, named haplotype A genome and haplotype B genome, are 487.33 Mb and 477.53 Mb in size, respectively, with contig N50 lengths of 31.45 Mb and 32.81 Mb. More than 99% of the assembled sequences were anchored to 13 pairs of pseudo-chromosomes. Furthermore, 21,587 and 21,533 protein-coding genes were predicted in haplotype A and haplotype B genomes, respectively. The availability of this chromosome-level genome fills the gap in genomic data for F. virosa and provides valuable resources for molecular studies of this species, supporting future research on speciation, functional genomics, and comparative genomics within the Phyllanthaceae family.

It Is Not All about Alkaloids-Overlooked Secondary Constituents in Roots and Rhizomes of Gelsemium sempervirens (L.) J.St.-Hil.

Gelsemium sempervirens (L.) J.St.-Hil. is an evergreen shrub occurring naturally in North and Middle America. So far, more than 120 alkaloids have been identified in this plant in addition to steroids, coumarins and iridoids, and its use in traditional medicine has been traced back to these compound classes. However, a comprehensive phytochemical investigation of the plant with a special focus on further compound classes has not yet been performed. Therefore, the present study aimed at an extensive HPLC-MSn characterization of secondary metabolites and, for the first time, reports the occurrence of various depsides and phenolic glycerides in G. sempervirens roots and rhizomes, consisting of benzoic and cinnamic acid derivatives as well as dicarboxylic acids. Furthermore, mono- and disaccharides were assigned by GC-MS. Applying the Folin-Ciocalteu assay, the phenolic content of extracts obtained with different solvents was estimated to range from 30 to 50% calculated as chlorogenic acid equivalents per g dry weight and was related to the DPPH radical scavenging activity of the respective extracts. Upon lactic acid fermentation of aqueous G. sempervirens extracts, degradation of phenolic esters was observed going along with the formation of low-molecular volatile metabolites.

Arbutus andrachne: The Antioxidant and Antiproliferative Activity of Fruit Extracts and the Phytochemical Composition of Essential Oil

Background: Arbutus andrachne L. is a perennial evergreen shrub widely distributed throughout the Mediterranean region. This plant holds great scientific significance owing to its nutritional, pharmacological, and chemical characteristics, making it a popular choice as a medicinal plant. It is well known for its diverse applications in science and medicine. Objectives: The primary purposes of this study were to explore the antioxidant and antiproliferative properties of A. andrachne and to identify the phytochemicals in A. andrachne essential oil. Methods: The fruits of A. andrachne L. were collected and taxonomically identified. Aqueous, ethanolic, and methanolic extracts were then prepared. The fruits of A. andrachne were subjected to advanced hydrodistillation to extract essential oils, which were carefully analyzed using gas chromatography-mass spectrometry (GC-MS) to identify their phytochemical components. A ferric-reducing antioxidant power assay was used to test the extracts' antioxidant activity. The colorimetric assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) was used to test the extracts' antiproliferative activity against five specific cell lines: T47D and MCF-7 (breast cancer), Caco-2 and HCT-116 (colorectal cancer), and MRC-5 (a standard fibroblast cell line used as a control). Results: The main findings indicated that the essential oil of the fruits comprises 35 different components. The main ingredient in A. andrachne fruits is pentadecanoic acid, 14-methyl-, methyl ester (19.87%). The methanolic extract exhibited the highest antioxidant activity (18.27 µmol/L Fe2+ equivalents). Furthermore, all tested extracts exerted weak antiproliferative activity against the tested cancerous cell lines and had no significant effect on normal cell lines. At 200 µg/mL, the aqueous, methanolic, and ethanolic extracts showed high viability of the treated cells across all tested cell lines (ranging from 99.30 - 100.00%). Conclusions: The A. andrachne crude extracts, with their non-cytotoxic activity on both cancerous and normal cells, present a promising natural source of antioxidants. This potential opens up various applications in the food and pharmaceutical industries, highlighting the relevance and impact of these findings.

Myrtus communis leaf extracts repel Meloidogyne spp. second‐stage juveniles and prevent root infection

AbstractThe use of repellents for nematode control has not been established. Leaf extracts of Myrtus communis, an evergreen shrub with wide distribution in the Mediterranean and some other regions, were tested for repellence of second‐stage juveniles (J2s) of Meloidogyne species. Extracts obtained with several solvents and water repelled M. javanica J2s on agar plates, with the 60% methanol extract showing the highest repellent activity. M. hapla J2s were also repelled by the aqueous and 60% methanol extracts. Adding the 60% methanol extract to fluopyram, a chemical J2 attractant, reduced and abolished, respectively, the attraction of M. javanica and M. hapla J2s to it. When the methanolic extract was added near lettuce seedling roots on an agar plate, the number of M. javanica, M. incognita and M. hapla J2s attracted to the root tips was reduced by 70.0%–98.2%, infection rates decreased by 50.1%–95.8% and root length increased by 61.8%–186.7% compared to control seedlings grown on the same plates. When the methanol extract was mixed into the agar plate, the three Meloidogyne species' attraction to and infection of lettuce seedlings was reduced by up to 75.4% and 100%, respectively, and root length increased up to 3.4‐fold. The acetone extract mixed into the agar reduced the attraction of M. javanica J2s to fluopyram but did not affect their repellence by KNO3. The results suggest that M. communis leaf extracts have repellent and infection‐inhibitory activity against Meloidogyne J2, offering potential control means for Meloidogyne species.

Cultivars and Production Environments Shape Shoot Endophyte Profiles of Boxwood with Different Blight Resistance

Phyllosphere colonizers, including bacteria and fungi, are critical for plant growth and health. However, how they are affected simultaneously by the host plant cultivar, local environment, and agricultural practices was not well understood. We used boxwood, an iconic landscape plant and a major evergreen shrub crop in the United States nursery industry, as a model plant and sequenced 16S rRNA and ITS amplicons to examine the assemblages of endophytic bacteria and fungi in the shoots of four cultivars representing three levels of boxwood blight resistance under two distinct climates and production systems in Oregon and Virginia. Cultivar and local environment were the two main drivers shaping the composition and structure of the boxwood endophytic microbial community, particularly the fungal community. Three bacterial and seven fungal genera were consistently identified with high prevalence and abundance as the core taxa from four cultivars and two locations across three sampling times. The microbial composition varied among the levels of boxwood blight resistance, and taxa specific to the tolerant cultivar were fewer compared to the susceptible one. Identification of these microbial indicators, along with the core taxa, is foundational for developing a microbiome-based plant breeding program and a systems approach to improve boxwood health and production under a changing climate. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Redefining the megagenus Erica L. (Ericaceae): the contributions of E. G. H. Oliver and I. M. Oliver (née Nitzsche) to taxonomy and nomenclature.

The megagenus Erica L. (Ericaceae), as it is recognised today, includes 851 species of evergreen shrubs or small trees, the majority of which are endemic to the Cape Floristic Region of South Africa. From the first descriptions in Linnaeus's Genera plantarum, a succession of authors ascribed the steadily accumulating numbers of known species to various of a total of 72 different genera. Until the latter half of the twentieth century, so called 'minor genera' such as Philippia Klotzsch and Blaeria L. were still recognised for many African species. The now uncontroversial inclusive circumscription of Erica, and a substantial proportion of its currently recognised species diversity, was conceptualised, described, and illustrated by the South African botanists E. G. H. ('Ted') Oliver and Inge M. Oliver in a succession of works published from 1964 to the present day. We review the historical development of generic delimitation in Erica sens. lat., focusing on the contribution of the Olivers to the current state of systematic knowledge of the genus, and presenting an overview and complete lists of literature and of taxa that they authored.