'' Vexatorella '' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

containing four

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

, commonly known as vexators, in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Proteaceae The Proteaceae form a family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genera with about 1,660 known species. Together with the Platanaceae and Nelumbonaceae, they make up the order Pro ...

. The genus is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Cape Floristic Region of

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. The name means “little trouble-maker”, given with reference to the initial difficulties of placing ''V. latebrosa'' within the family. All species are

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s which occur in dry

fynbos Fynbos (; meaning fine plants) is a small belt of natural shrubland or heathland vegetation located in the Western Cape and Eastern Cape provinces of South Africa. This area is predominantly coastal and mountainous, with a Mediterranean clim ...

habitats on the fringes of the

Succulent Karoo The Succulent Karoo is a ecoregion defined by the World Wide Fund for Nature to include regions of desert in South Africa and Namibia, and a biodiversity hotspot. The geographic area chosen by the WWF for what they call 'Succulent Karoo' does no ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s are similar to those of the related

leucospermum ''Leucospermum'' is a genus of evergreen upright, sometimes creeping shrubs that is assigned to the Proteaceae, with currently forty-eight known species. Almost all species are easily recognised as ''Leucospermum'' because of the long protruding ...

s but also share features of the

leucadendron ''Leucadendron'' is a genus of about 80 species of flowering plants in the family Proteaceae, endemic to South Africa, where they are a prominent part of the fynbos ecoregion and vegetation type. Description Species in the genus ''Leucadendron' ...

s, with the floral

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s becoming woody and enlarged following pollination. The flowers are insect-pollinated, with the seeds dispersed by

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

s (

myrmecochory Myrmecochory ( (sometimes myrmechory); from grc, μύρμηξ, mýrmēks ("ant") and ''khoreíā'' ("circular dance") is seed dispersal by ants, an ecologically significant ant–plant interaction with worldwide distribution. Most myrmeco ...

Description

Vexators are upright or spreading

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrubs with alternately set, narrow, spade-shaped leaves ending bluntly in a bony tip, with an entire margin, and greyish or bluish in colour. The

stalked Stalking is unwanted and/or repeated surveillance by an individual or group toward another person. Stalking behaviors are interrelated to harassment and intimidation and may include following the victim in person or monitoring them. The term ...

flower heads are mostly set individually, sometimes with two to six together at the end of the stems, opening from the center outwards. The individual flowers are 4-merous, star symmetrical and

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

. The four

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower, and structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepals when ...

segments are pink or cream-coloured, and have a sweet smell. From their center, a straight

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

emerges that is hairless or powdery. The thickened part at its tip called

pollen presenter A pollen-presenter is an area on the tip of the style in flowers of plants of the family Proteaceae on which the anthers release their pollen prior to anthesis. To ensure pollination, the style grows during anthesis, sticking out the pollen-present ...

is cleft at its tip. The

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

is egg- to bottle-shaped, consists of one

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

and contains just one

cavity Cavity may refer to: Biology and healthcare *Body cavity, a fluid-filled space in many animals where organs typically develop **Gastrovascular cavity, the primary organ of digestion and circulation in cnidarians and flatworms *Dental cavity or too ...

with one hanging primordial seed. The ovary is subtended by four free awl-shaped scales. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is an egg-shaped hairless or powdery

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

, that is beaked at its tip, and blunt and wrinkly at its base. The bracteoles that support the individual flowers become woody after flowering, a character that set ''Vexatorella'' apart from ''

Leucospermum ''Leucospermum'' is a genus of evergreen upright, sometimes creeping shrubs that is assigned to the Proteaceae, with currently forty-eight known species. Almost all species are easily recognised as ''Leucospermum'' because of the long protruding ...

'' except for '' L. secundifolium'' that also develops woody bracteoles.

Taxonomy

Comparison of homologous DNA has increased the insight in the phylogenetic relationships between the Proteaceae. ''Vexatorella'' belongs to a group that (except for ''

Leucospermum saxosum ''Leucospermum saxosum'' is an upright evergreen shrub of up to high, that is assigned to the family Proteaceae. It has lance-shaped, leathery leaves and egg-shaped flower heads of about in diameter, with initially yellow-orange flowers, later ...

'') further only consists of genera endemic to the Cape Floristic Region, that together constitute the

subtribe Subtribe is a taxonomic category ranking which is below the rank of tribe and above genus. The standard suffix for a subtribe is -ina (in animals) or -inae (in plants Plants are predominantly photosynthetic eukaryotes of the kingdom Plant ...

Leucadendrinae. ''Vexatorella'' is the closest relative of ''

Paranomus ''Paranomus'' is a genus of 18 species of flowering plants, commonly known as "sceptres", in the protea family. It is endemic to the Cape Floristic Region of South Africa. Distribution and habitat The species occur mainly in mountainous a ...

''. The genera '' Sorocephalus'' and '' Spatalla'' are the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the ''Vexatorella'' and ''Paranomus''. The following trees together represent those insights. The described subtaxa are: * ''

Vexatorella alpina ''Vexatorella alpina'', the Kamiesberg vexator, is an evergreen, upright shrub of up to about 1½ m high, in the family Proteaceae. It has entire, long inverted egg-shaped, bluish grey, leathery leaves of 3–4½ cm (1.2–1.8 in) long and 5 ...

'' (Salisb. ex Knight) Rourke – Kamiesberg vexator * '' Vexatorella amoena'' (Rourke) Rourke – Swartruggens vexator * '' Vexatorella latebrosa'' Rourke – Robertson vexator * ''

Vexatorella obtusata ''Vexatorella obtusata'' is an evergreen shrub, with narrow, leathery leaves and about 2 cm big, globular flowerheads consisting of well scented, creamy pink flowers, from which a long style with a thickened tip extends. Two subspecies are d ...

'' (Thunb.) Rourke ** ''Vexatorella obtusata'' subsp. ''obtusata'' – Montagu vexator ** ''Vexatorella obtusata'' subsp. ''albomontana'' – Witteberg vexator File:Vexatorella alpina 1.jpg, Kamiesberg vexator File:Vexatorella amoena Helme 1.jpg, Swartruggens vexator File:Vexatorella latebrosa Helme 1.jpg, Robertson vexator File:Vexatorella obtusata albomontana Rebelo 3.jpg, Witteberg vexator File:Vexatorella obtusata obtusata Rebelo 2.jpg, Montagu vexator

Conservation

Of the four species and two subspecies, the continued survival of three taxa, ''Vexatorella amoena'' and of ''V. obtusata'' both subsp. ''albomontana'' and ''obtusata'', is considered to be of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

. ''V. alpina'' is thought to be a

near-threatened species A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

. ''Vexatorella latebrosa'' on the other hand regarded as being critically endangered.

References

{{Taxonbar, from=Q10389983 Proteaceae genera Endemic flora of South Africa Flora of the Cape Provinces