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47-434: The Primulaceae ( / ˌ p r ɪ m j ə ˈ l eɪ ʃ i . iː / PRIM -yə- LAY -shee-ee ), commonly known as the primrose family (but not related to the evening primrose family ), are a family of herbaceous and woody flowering plants including some favourite garden plants and wildflowers. Most are perennial though some species, such as scarlet pimpernel , are annuals . Previously one of three families in

94-418: A family of flowering plants known as the willowherb family or evening primrose family . They include about 650 species of herbs , shrubs , and trees in 17 genera. The family is widespread, occurring on every continent from boreal to tropical regions. The family includes a number of popular garden plants, including evening primroses ( Oenothera ) and fuchsias ( Fuchsia ). Some, particularly

141-432: A hierarchical system of ranks based on the relative value of a much wider range of characteristics. In his Genera plantarum (1789) he organised the primuloid genera into two Ordo ( families ), within a class (VIII) he called Dicotyledones Monopetalae Corolla Hypogyna , based on the cotyledons (two), form of the petals (fused), and position of the corolla with respect to the ovary (below). Jussieu's families were

188-732: A vicariant event between the Neotropics and the Palearctic in the case of the latter. The Primuloideae originating in the Palearctic, persisted till the last 16 mya, when it started to shift into the Nearctic . The three former families of the Primulales, together with the segregated Maesaceae, have been re-circumscribed into the broadly defined Primulaceae sensu lato ( s.l. ) The two uniting features of this family are

235-878: A basal rosette, and ovules rarely immersed in the placenta. In addition they often have syncolpate or sometimes polycolpate pollen , without margo. Subdivision has included the tribes Androsaceae and Primulae. Takhtajan (1997) gives the four genera of Androsaceae as Androsace (including Douglasia ), Vitaliana , Stimpsonia and Pomatosace , and the ten genera of Primulae as Omphalogramma , Bryocarpum , Primula , Dionysia , Cortusa , Kauffmannia , Hottonia , Srediskya , Dodecatheon and Soldanella . In contrast Kallersjo et al. (2000) place all genera in Primulae, and list thirteen in all: Androsace , Douglasia , Omphalogramma , Soldanella , Dodecatheon , Cortusa , Primula , Dionysia , Vitaliana , Hottonia , Bryocarpum , and Pomatosace . These two (or one) tribes represent

282-425: A century. There are the two major hypotheses: The triploid transition - and the production of antipodal cells - may have occurred due to a shift in gametophyte development which produced a new interaction with an auxin-dependent mechanism originating in the earliest angiosperms. In some groups (e.g. grains of the family Poaceae ), the endosperm persists to the mature seed stage as a storage tissue, in which case

329-547: A feature considered synapomorphic . His circumscription of Primulaceae included about 800 species. These three families were referred to as the primuloid families. With the later development of molecular phylogenetic methods, the Primulales were found to be more closely related to other families within the Ericales , and the three primuloid families were subsequently absorbed into an expanded Ericales (Ericales sensu lato or s.l. ), making 24 families within that order, where

376-405: A few inches high) and their stems are stiffened by lignin . The stems can grow upright ( erect ) or spread out horizontally and then turn upright ( decumbent ). Leaves are simple , being directly attached to the stem by a petiole (stalk), but unlike the leaves of most flowering plants they have no stipules . The petiole is short or the leaf tapers gradually towards the base. Leaf arrangement

423-717: A free central placenta and one stamen opposite each of the corolla lobes. The cladogram below shows the infrafamilial phylogenetic relationships, together with the subfamilial crown ages. Maesoideae forms the basal group, while Primuloideae and Myrsinoideae are in a sister group relationship. Maesoideae Theophrastoideae Primuloideae Myrsinoideae Christenhusz et al. (2016, 2017) list 2,790  species and 53  genera , varying from 1 in Maesoideae to 38 in Myrsinoideae, with 8 in Theophrastoideae and

470-446: Is a characteristic feature of angiosperms . There are three types of endosperm development: Nuclear endosperm development – where repeated free-nuclear divisions take place; if a cell wall is formed it will form after free-nuclear divisions. Commonly referred to as liquid endosperm. Coconut water is an example of this. Cellular endosperm development – where a cell-wall formation is coincident with nuclear divisions. Coconut meat

517-432: Is cellular endosperm. Acoraceae has cellular endosperm development while other monocots are helobial. Helobial endosperm development – where a cell wall is laid down between the first two nuclei, after which one half develops endosperm along the cellular pattern and the other half along the nuclear pattern. The evolutionary origins of double fertilization and endosperm are unclear, attracting researcher attention for over

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564-580: Is distinguished as Myrsinaceae s.l. in comparison to the previous smaller family, Myrsinaceae s.s. (less Maesa ). Some authors preferred to raise Samoleae to its own family, Samolaceae, but this has not been accepted by subsequent authors, placing it within Theophrastaceae, while recognising its distinct position within that grouping. These transfers, to preserve monophyly at the family level essentially left two tribes remaining in Primulaceae,

611-463: Is distributed in both tropical and subtropical regions of the Old World, ranging from East Africa to Japan. Once included in the Primulaceae tribe Samoleae, it has most commonly been considered as part of family Myrsinaceae, till segregated into its own family and then submerged as a Primulaceae s.l. subfamily. It has characteristics that distinguish it from Myrsinaceae and forms the basal group of

658-414: Is formed after the two sperm nuclei inside a pollen grain reach the interior of a female gametophyte or megagametophyte, also called the embryonic sac . One sperm nucleus fertilizes the egg cell , forming a zygote , while the other sperm nucleus usually fuses with the binucleate central cell, forming a primary endosperm cell (its nucleus is often called the triple fusion nucleus ). That cell created in

705-456: Is often tubular. The eight genera are confined to South and Central America. Samolus is a distinct genus, being sister to all other Theophrastoideae. Previously it formed its own tribe, Samoleae within Primulaceae s.s. , and in some systems, its own family, Samolaceae, but was subsequently transferred to Theophrastoideae. The Primulaceae are named for their nominative and type genus, Primula . Linnaeus used this name to reflect its place among

752-410: Is typically alternate but some are opposite or whorled, and there is generally a rosette at the base of the stem. The edges are toothed ( dentate ) or sawtoothed. New leaves in the bud are usually involute (rolled towards the upper surface) or conduplicate (folded upwards), but a few species roll downwards. Each flower is bisexual , having both stamens and carpels . They have radial symmetry ;

799-666: The Asterids (Asteridae). Maesa was formally segregated in 2000. Further changes came from analysis of DNA sequence data. This led to the move of genera (primarily terrestrial non-basal-rosette) from Primulaceae to Mysinaceae and Theophrastaceae. At that time Primulaceae was considered to consist of nine tribes (Primuleae, Androsaceae, Ardisiandreae, Lysimachieae, Glauceae, Anagallideae, Corideae, Cyclamineae, and Samoleae). Notably, Lysimachieae and three smaller tribes, Corideae, Cyclamineae and Ardisiandreae, were transferred to Myrsinaceae, and Samoleae to Theophrastaceae. This enlarged Myrsinaceae

846-603: The nucellus produces a nutritive tissue termed "perisperm". The endosperm of some species is responsible for seed dormancy . Endosperm tissue also mediates the transfer of nutrients from the mother plant to the embryo, it acts as a location for gene imprinting, and is responsible for aborting seeds produced from genetically mismatched parents. In angiosperms, the endosperm contain hormones such as cytokinins , which regulate cellular differentiation and embryonic organ formation. Cereal crops are grown for their edible fruit (grains or caryopses ), which are primarily endosperm. In

893-648: The order Primulales , it underwent considerable generic re-alignment once molecular phylogenetic methods were used for taxonomic classification . The order was then submerged in a much enlarged order Ericales and became a greatly enlarged Primulaceae sensu lato ( s.l ). In this new classification of the Angiosperm Phylogeny Group , each of the Primulales families was reduced to the rank of subfamily of Primulaceae s.l. The original Primulaceae (Primulaceae sensu stricto or s.s. ) then became subfamily Primuloideae, and one genus ( Maesa )

940-558: The petals can be separate or partially or fully fused together to form a tube-shaped corolla that opens up at the mouth to form a bell-like shape (as in item 8 in the figure) or a flat-faced flower. In most of the families of Ericales, stamens alternate with lobes, but in Primulaceae there is a stamen opposite each petal. The calyx has 4 to 9 lobes and persists after flowering. They are grouped in unbranched, indeterminate clusters such as racemes, spikes, corymbs or umbels. The fruit of Primulaceae begins as an ovary and inside it are

987-742: The Lysimachiae, including Primula and Theophrasta and the Sapotae , including Myrsine , these being the three main lineages in modern understanding. The most complete treatment of the Primulaceae family , with nearly 1,000 species arranged into 22 genera , was by Pax and Knuth in 1905 in the Engler system . They divided the family into five tribes (and several subtribes); Androsaceae, Cyclamineae, Lysimachieae, Samoleae and Corideae. Many systems since have lacked consistency, but generally recognised two major groups as either tribes or subfamilies,

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1034-617: The Lysimachieae and Primuleae (the Androsaceae of Pax and Knuth), with the largest genera being Primula , Lysimachia and Androsace . In the Cronquist system (1988), Cronquist included the three closely related families, Primulaceae, Myrsinaceae and Theophrastaceae in the order Primulales , of subclass Dilleniidae , based on morphological characteristics, in particular, ovaries with free-central placentation,

1081-589: The Primulaceae subfamilies vary from 24 mya for the Maesoideae, the basal group , to 70 mya for the Theophrastoideae. The primuloids probably originated in a shared Neotropical / Indo-Malaysian ancestral range , with the Primulaceae/Ebenaceae clade occupying the neotropics. Theophrastoideae is nearly all neotropical with a more recent migration out of the realm found in the aquatic Samolus genus. The divergence between Theophrastoideae and Primuloideae-Myrsinoideae at 70 mya represents

1128-589: The Primuleae and Androsaceae, with about 15 genera sharing a number of common characteristics. These additional changes were reflected in the 2003 revision of the APG system (APG II), where the now four primuloid families were among 23 in Ericales. This restricted Primulaceae sensu stricto ( s.s. ) consisted of three groups: The Primulae, including Primula , the largest genus; the Androsaceae, including Androsace ,

1175-413: The caryopsis, the thin fruit wall is fused to the seed coat. Therefore, the nutritious part of the grain is the seed and its endosperm. In some cases (e.g. wheat, rice) the endosperm is selectively retained in food processing (commonly called white flour ), and the embryo ( germ ) and seed coat ( bran ) removed. The processed grain has a lower quality of nutrition. Endosperm thus has an important role within

1222-407: The clade as sister to all other subfamilies. The relatively large Myrsinoideae, has been treated as a number of tribes, e.g. Ardisieae and Myrsineae, and more recently Lysimachiaeae, a transfer from Primulaceae s.s. Ardisieae and Myrsineae represent the woody clades within the subfamily. Within the Myrsinoideae, the genera represented by the restricted Myrsinaceae s.s. , prior to the transfers from

1269-446: The embryo through free division of nuclei without forming walls ( nuclear endosperm formation ). The embryo forms a pair of short, narrow cotyledons (item 10 in the figure). Usually multiple seeds are in a capsule that is carried on a straight stalk ( pedicel or scape ). After it matures, it splits apart , releasing the seeds ballistically. The taxonomic history of Primulaceae has been long and complex. The botanical authority for

1316-686: The family name is given to August Batsch (1794), as Batsch ex Borkh, using the term Primulae with six genera, the valid description being subsequently given by Borkhausen (1797). Some earlier authors attributed the name to Ventenat (1799), as Primulaceae Vent., who described the Primulacées, but Batsch had precedence. Linnaeus (1753) placed Primula and related primuloid genera in the Hexandria Monogynia (six stamens one pistil ) in his sexual classification based on reproductive characteristics. Jussieu arranged Linnaeus' genera in

1363-485: The first flowers of spring, given the primrose's vernacular Latin name of primula veris ( lit.   ' little first of spring ' ), primula (feminine diminutive primus , first + veris (genitive ver , spring). Distribution is cosmopolitan. The British National Collection of Double Primroses is held at Glebe Garden, at North Petherwin , in North Cornwall . Onagraceae The Onagraceae are

1410-453: The flowers; nearly all bee taxa that visit the flowers are oligoleges specialized on the family Onagraceae. The family was named after the genus Onagra (now known as Oenothera ) in 1836 by John Lindley in the second edition of A Natural System of Botany . Several genera are synonymized in the classification presented above, in particular Calylophus and Gaura , which have both been absorbed into Oenothera but appear often in

1457-569: The following cladogram , consists of seven major suprafamilial clades (e.g. balsaminoids, styracoids) and a group of "core" Ericales. Within the eracalean families, Primulaceae s.l. is shown as a sister group to Ebenaceae , and both are sister to Sapotaceae . These three families make up the primuloid clade. The fossil record of Primulaceae s.l. is sparse, but the crown group has been estimated as c. 46-61 million years old. The crown primuloids have been dated to c. 102 mya , with Primulaceae/Ebenaceae divergence at 80 mya. Crown ages for

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1504-409: The four primuloid families were reduced to the rank of subfamilies within Primulaceae s.l. Primulaceae s.l. sensu APG III form part of the speciose (species rich) Asterid order Ericales s.l. , with about 12,000 species and 22 families as per APG IV. Ericales is one of four major clades within the asterids, where it is sister to the euasterids . The phylogenetic structure of Ericales, as shown in

1551-406: The fusion of a pollen nucleus with one, rather than two, maternal nuclei. The same is supposed for some other basal angiosperms. It is believed that early in the development of angiosperm lineages, there was a duplication in this mode of reproduction, producing seven-celled/eight-nucleate female gametophytes, and triploid endosperms with a 2:1 maternal to paternal genome ratio. Double fertilisation

1598-410: The future seeds ( ovules ). These are attached to a central axis without any partitions between them (an arrangement called free central placentation ; see item 7 in the figure), and they are bitegmic (having a double protective layer around each ovule). Unlike in most other families of Ericales, both layers form the opening at the top (the micropyle ). As seeds develop, an endosperm grows around

1645-461: The literature as belonging to the previous genera. Endosperm Ancestral flowering plants have seeds with small embryos and abundant endosperm. In some modern flowering plants the embryo occupies most of the seed and the endosperm is non-developed or consumed before the seed matures. In other flowering plant taxa, the Poaceae for example, the endosperm is greatly developed. An endosperm

1692-480: The primuloids formed a monophyletic clade . It was also apparent that Myrsinaceae were paraphyletic, unless the genus Maesa was segregated and elevated to become a new monogeneric family, Maesaceae , but also that Primulaceae were probably paraphyletic. In the first consensus taxonomic classification, the Angiosperm Phylogeny Group (APG 1998), these proposals were recognised by including Primulaceae within Ericales, as Eudicots , forming one of three clades in

1739-521: The process of double fertilization develops into the endosperm. Because it is formed by a separate fertilization event, the endosperm is a separate entity from the developing embryo, and some consider it to be a separate organism . About 70% of angiosperm species have endosperm cells that are polyploid . These are typically triploid (containing three sets of chromosomes ), but can vary widely from diploid (2n) to 15n. One flowering plant, Nuphar polysepala , has diploid endosperm, resulting from

1786-620: The remaining 6 in Primuloideae. Byng (2014) and Plants of the World Online list 55 accepted genera. The generic limits of Myrsinoideae are not fully resolved and the status of a number of genera is under revision. Maesoideae is a monogeneric subfamily, whose single genus is Maesa Forssk. It is a genus of trees. The flowers are small, with short tubules and semi-inferior ovary, arranged in axillary or terminal racemes , or in panicles . Maesa has about 100 species, and

1833-408: The remaining genera in Primuloideae (Primulaceae s.s. ) following redistribution among the Primulales on molecular grounds. The 600 species mainly belong to Androsace and Primula and belong to the mountainous regions of Europe and Asia (mainly China). Theophrastoideae consist of a relatively small subfamily, whose flowers are staminodial and bear berries . The ovary is superior, and the corolla

1880-428: The second largest genus; together with a small third group containing Soldanella , Hottonia , Omphalogramma and Bryocarpum . The APG third classification system (APG III, 2009) discussed all the taxonomic challenges arising from the phylogenetic studies, and placed all primuloid genera into one large Primulaceae s.l. , corresponding to Cronquist's Primulales. They stated that "The biggest problem for APG III

1927-407: The seeds are called "albuminous" or "endospermous", and in others it is absorbed during embryo development (e.g., most members of the family Fabaceae , including the common bean , Phaseolus vulgaris ), in which case the seeds are called "exalbuminous" or "cotyledonous" and the function of storage tissue is performed by enlarged cotyledons ("seed leaves"). In certain species (e.g. corn, Zea mays );

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1974-444: The storage function is distributed between both endosperm and the embryo. Some mature endosperm tissue stores fats (e.g. castor bean , Ricinus communis ) and others (including grains, such as wheat and corn) store mainly starches. The dust-like seeds of orchids have no endosperm. Orchid seedlings are mycoheterotrophic in their early development. In some other species, such as coffee , the endosperm also does not develop. Instead,

2021-679: The then Primulaceae, form a distinct clade. Genera in Lysimachiaeae are Trientalis , Anagallis , Glaux , Lysimachia , Asterolinon and Pelletiera . Coris had its own tribe within Primulaceae s.s. , Corideae, but its molecular affinities led to its transfer to Myrsinoideae. Similarly, Ardisiandra was the tribe Ardisiandreae and Cyclamen the tribe Cyclamineae. The subfamily is characterised by scapose inflorescences , distinctly tubular flowers having campanulate or hypocrateriform corolla, imbricate corolla aestivation , isodiametric corolla epidermal cells, leaves almost always forming

2068-474: The willowherbs ( Epilobium ), are common weeds in gardens and rapidly colonize disturbed habitats in the wild. One such species is fireweed ( Chamaenerion angustifolium ). The family is characterised by flowers with usually four sepals and petals ; in some genera, such as Fuchsia , the sepals are as brightly coloured as the petals. The seeds are generally very small. In some genera, such as Epilobium , they have tufts of hairs and are dispersed on

2115-421: The wind. In others, such as Fuchsia , the seeds develop in juicy berries dispersed by animals. The leaves are commonly opposite or whorled, but are spirally arranged in some species; in most, they are simple and lanceolate in shape. The pollen grains in many genera are loosely held together by viscin threads. Most bees cannot collect it, and only bees with specialized morphologies can effectively pollinate

2162-491: Was raised to the rank of a separate subfamily, making four in all. The family shares a number of characteristics, including haplostemonous flowers having the same number of petals and stamens, sympetalous corolla having the petals united, stamens opposite the petals , free central placentation , bitegmic (two layered) ovules and nuclear endosperm formation. Primulaceae are mostly herbaceous , having no woody stem, except that some form cushions (spreading mats

2209-453: Was the question of how to treat Primulaceae and their immediate relatives, a closely related group that in the past has often been recognized as a separate order". The decision to treat all genera as a single family was based on the observation that the new circumscriptions had little in the way of apomorphies , but the entire group had numerous synapomorphies and were easy to recognise. This resulted in an Ericales with 22 families. Consequently,

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