Asparagales

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The Asparagales (alias:Asparagoid Lilies) is an order of plants in modern classification systems, It is the next level of classification of Liliidae. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots.

Most species are horticulturally important ornamental plants. Orchidaceae flowers have unique traits adapted to insect pollination. Manifested as: large, beautiful, fragrant flowers, easy to attract insects, nectary glands are located in the distance from the base of the lip or at the base of the cystium; when insects land on the lip to collect honey, the head just touches the cystium On the sticky disc at the base of the upper pollen block, when the insect leaves, it takes the pollen block away, and when another flower collects nectar, the pollen block just touches the stigma with mucus again, completing the pollination.

As circumscribed within the Angiosperm Phylogeny Group system Asparagales is the largest order within the monocotyledons, with 14 families, 1,122 genera and about 25,000–42,000 species, thus accounting for about 50% of all monocots and 10–15% of the flowering plants (angiosperms). The attribution of botanical authority for the name Asparagales belongs to Johann Heinrich Friedrich Link (1767–1851) who coined the word 'Asparaginae' in 1829 for a higher order taxon that included Asparagus although Adanson and Jussieau had also done so earlier (see History). Earlier circumscriptions of Asparagales attributed the name to Bromhead (1838), who had been the first to use the term 'Asparagales'.

Asparagales is a new class of monocotyledonous plants classified according to the 1998 APG classification and the 2003 APG II classification. The previous plant classification did not have this category, and many of the families were divided into Liliaceae and Orchids, respectively. of. However, according to the genetic testing of molecular biology, it is considered that these plants belong to the same category, so this item was established. This order includes 25 families including Amaryllidaceae, Irisaceae , Orchidaceae, and Amaryllidaceae, Asparagaceae, Hemerocallisaceae, and Hyacinthaceae separated from the generalized Liliaceae. Orchidaceae with highly specialized flowers in this order are considered to be the most evolved groups among monocotyledonous plants, which evolved from Liliaceae.

Few groups of angiosperms are in such taxonomic ferment as Asparagales. Beginning in the 1980s, significant rearrangements were made by the Swedish botanist Rolf Dahlgren and his colleagues to the genera and families that were formerly recognized in the subclass Liliidae in the Cronquist botanical classification system. Under the reorganization, families such as Philydraceae, Pontederiaceae, Haemodoraceae, and Velloziaceae have been excluded, and the remaining taxa have been realigned into three substantially different orders: Dioscoreales (the yam order), Liliales (the lily order), and Asparagales.

Under the Angiosperm Phylogeny Group IV (APG IV) botanical classification system, Asparagales comprises two major groups of families. These are based primarily on molecular evidence but also on patterns of pollen development. The “core Asparagales” are a natural group made up of two families: Asparagaceae (the asparagus family, with 2,525 species in 153 genera) and Amaryllidaceae (the daffodil family, with at least 1,605 species in 73 genera). The “lower Asparagales” include Orchidaceae (the orchid family, with more than 26,000 species in nearly 880 genera), Asteliaceae (the silver spear family, with 31 species in 3 genera), Hypoxidaceae (the star lily family, with 100–220 species in 7–9 genera), Iridaceae (the iris family, with more than 2,120 species in some 66 genera), Asphodelaceae (the aloe family, with 785–940 species in 19 genera), and a number of small families (e.g., Blandfordiaceae, Lanariaceae, Boryaceae, Ixioliriaceae, Tecophilaeaceae, Doryanthaceae, and Xeronemataceae).

To a large extent, many of the families in Asparagales are defined primarily by DNA characters, and unique morphological characters are not obvious within families. For this reason, it is often difficult to identify the family into which a genus should be placed without laboratory analysis. However, as molecular evidence accumulates for distinguishing families and relationships within Asparagales, additional and new morphological features are being identified for recognizing these taxa.

Amaryllidaceae, Amaryllis Family

The family is a bulbous herbaceous family, with about 50 genera and more than 870 species, widely distributed in temperate to subtropical regions, mainly in southern Africa and South America; most species are ornamental plants of important horticultural value. The systematic position of the family has always been controversial, because it is very close to the Liliaceae, some put it into the Liliaceae (such as the Cronquist system); Using Liliaceae in the narrow sense, Amaryllidaceae is placed in the order of Asparagus.

mostly according

The type of underground stem, whether the plant has leaves when it blooms, whether the flowers have coronas, whether the filaments are free or conjoined, and the type of fruit.

Orchidaceae, Orchid Family

The family is the highest group of monocotyledonous plants whose flower structure is adapted to insect pollination. About 775 genera and 19,500 species are widely distributed in tropical, subtropical and temperate regions, mainly in South America and tropical Asia. Orchidaceae is the second largest family of seed plants. Apart from bletilla striata and Gastrodia elata, which can be used medicinally, there are many kinds of precious ornamental plants;

Morphological characteristics

Perennial terrestrial, epiphytic or saprophytic herb, terrestrial and saprophytic species often have rhizomes or tubers, and epiphytic aerial roots with fleshy flesh. Stems erect, pendant, or climbing, often swollen at base or entirely into pseudobulbs with one or more nodes. Single leaves alternate, often in two rows, sometimes reduced to scales. Scapes terminal or lateral on pseudobulbs, spicate, raceme, panicle or solitary; bisexual, bisexual; tepals 6, 2 whorls; outer whorl 3 sepals petal-like, inner whorl side There are 2 pieces of similar size, called petals, and the central piece is often specialized into a lip, showing various special shapes; the ovary is often twisted 180 degrees; stamens are usually 1, less 2 or 3, and the prominent ones are formed by the combination of stamens and pistil styles Column or ynostemium; pollen often integrated into 2~8 pollen blocks; pistil 3 carpels connate, 1 room, ovary inferior, parietal placenta; stigma 3, in single stamen species, 2 develop , a pistil beak. In bistamen species, 3 unite to form a single stigma. Capsule, very many seeds, tiny, embryo small and undifferentiated, without endosperm. Chromosome: X=6~29. Pollen 1~2 furrows, 3~4 holes.

Orchidaceae flowers have unique traits adapted to insect pollination. Manifested as: large, beautiful, fragrant flowers, easy to attract insects, nectary glands are located in the distance from the base of the lip or at the base of the cystium; when insects land on the lip to collect honey, the head just touches the cystium On the sticky disc at the base of the upper pollen block, when the insect leaves, it takes the pollen block away, and when another flower collects nectar, the pollen block just touches the stigma with mucus again, completing the pollination.

Undergraduate Classification Basis

Habit, tuber presence and shape, pseudobulb presence and shape, inflorescence type and location, perianth (especially lip) and symphylum shape and other traits.

Iridaceae

Perennial herb, leaves compressed on both sides, base infolded; perianth petal-shaped; ovary inferior, style 3-lobed and petal-shaped. There are many kinds of iris (I. tectorum Maxim.), iris (I. japonica Thunb.) and German iris (I. germanica L.) of the genus Iris (Iris), which are cultivated for ornamental or medicinal purposes. Small calamus (Freesia refracta Klatt) and gladiolus (Gladiolus gandavensis Van Houtte), native to South Africa, are famous ornamental flowers and are often used for flower arrangement. Shegan [Belamcanda chinensis (L.) DC.] is a common medicinal plant.

Morphological characteristics

Herbs perennial, often with bulbs or rhizomes. Ye Jisheng, bar-shaped. Flowers often form umbels, born on the top of the flower stem, with an involucre composed of 1~several membranous bracts; flowers bisexual, perianth petal-shaped, lobes 6 into 2 rounds, sometimes with corona; stamens 6; ovary Inferior, often 3-loculed, axial placenta, numerous ovules. Capsule or berry. Chromosome X=6~12, 14, 15, 23; pollen is often single groove.