What types of inflorescences are there?

1) Infinite inflorescence (infinite inflorescence) Infinite inflorescence is also called raceme, which is characterized by the fact that the main axis of inflorescence can continue to grow and elongate upwards when flowering, producing bracts and flower buds constantly, just like uniaxial branches, so it is also called uniaxial inflorescence. The opening sequence of each flower is that the flowers at the base of floral axis first open, then push up in order, and then open in turn. If the inflorescence axis is shortened and the flowers are densely flat or spherical, the flowering sequence starts from the edge and then opens to the center in turn. Infinite inflorescences can be divided into the following types: 1. The raceme floral axis is simple and long, and the flowers are stalked from bottom to top. The pedicel length of each flower is roughly equal, and the flowering order is from bottom to top, such as the inflorescence of wisteria, shepherd's purse and rape. 2. Spike floral axis stands upright and has many sessile florets. Small flowers are bisexual. Many plants of Gramineae, Cyperaceae, Amaranthaceae and Polygonum have spikes. 3. The catkin is soft in floral axis, and there are many parthenocarps (male or female) without stalks or short stalks on it. Flowers without perianth or perianth, inflorescence flexible, drooping or erect. After flowering, the whole inflorescence often falls off together. Such as inflorescences of poplars and willows; Male inflorescence of oak, hazel, etc. 4. Umbrella inflorescence, or flat-topped raceme, is a deformed raceme. Different from raceme, the length of each flower stalk on the inflorescence is different, and the lower flower stalk is the longest, and the shorter it is near the upper part of floral axis, so that the flowers on the whole inflorescence are almost arranged on a plane. Flowers have pedicels, which are arranged near the top of inflorescence axis. The pedicel at the bottom becomes longer and shorter, and the flowers are located on an approximate plane, such as hemp leaf hydrangea and hawthorn. If several corymbose inflorescences are arranged near the top of inflorescence axis, they are called compound corymbose inflorescences, such as Spiraea. A deformed raceme. The flowering sequence is from outside to inside. Such as pears, apples and cherry blossoms. 5. The floral axis of the flower head is very short and spread, flat and spread. Bract leaves are usually integrated into involucre, and flowers are sessile. Most flowers gather on the receptacle to form a flower head. Such as chrysanthemum, dandelion, sunflower, etc. 6. The axis of cryptocephalus is particularly enlarged and invaginated into a hollow shape. Many sessile florets are hidden in the cavity wall, almost all of them disappear, and only a small hole is left at the top of the whole inflorescence to communicate with the outside world, which is the channel for insects to spread pollen in and out of the cavity. Small flowers are unisexual, the male flowers are distributed in the upper part of the inner wall, and the female flowers are distributed in the lower part, such as figs and Ficus pumila. 7. The floral axis of umbel is shortened, and most peanuts are at the top of floral axis. Each flower has a pedicel of almost equal length, and many flowers with almost equal pedicels protrude from the top of the pedicel. The whole inflorescence is umbrella-shaped, called umbel. Each peduncle is called an umbrella peduncle. Such as primrose, dark plum, ginseng, acanthopanax senticosus, ivy, etc. 8. The basic structure of the spike is the same as that of the spike, but the difference is that floral axis is short and thick, fleshy, and most of the flowers are unisexual, such as the female inflorescence of corn and cattail. Some spikes are covered with a layer of big bracts, which are called Buddha's bracts, so this kind of inflorescence is also called Buddha's flame, such as Pinellia ternata, Arisaema, and taro. Floral axis of all inflorescences listed above are unbranched, so they are single inflorescences. Other infinite inflorescences have branches on the floral axis, and each branch presents one of the above inflorescences, which is called compound inflorescence. Common ones are: 1, panicle, also known as compound raceme. There are many branchlets on floral axis, and each branch has its own raceme, such as southern Tianzhu, rice, oats and yucca. 2. There are several branches with the same length at the top of floral axis, each branch becomes an umbel, and one branch forms its own umbel, such as carrot, peucedanum and fennel. 3. The branches of the inflorescence axis of the compound corymb are arranged in an umbrella shape, and each branch forms its own corymb, such as Sorbus pohuashanensis. 4. There are 1 or 2 spike branches on the axis of compound spike inflorescence, and each branch forms its own spike, i.e. spikelet, such as wheat and crabgrass. 5. Compound flower heads There are branches on a single flower head, and each branch forms its own flower head, such as chrysanthemum. Limited inflorescence [edit this paragraph] (2), limited inflorescence (define inflorescence) Limited inflorescence is also called cyme. Contrary to the infinite inflorescence, the flower at the top or center of floral axis blooms first, so the growth of the main shaft is restricted and continues to grow from the lateral axis, but the flower at the top also blooms first on the lateral axis, so the flowering order is from top to bottom or from inside to outside. It can also be divided into the following categories: 1, a single cyme with flowers at the top of the main inflorescence, and then a side branch is formed on one side of the main inflorescence below the top flower, and there are flowers at the end of the side branch, and there are branched flowers on the side branch as before, so the whole inflorescence is a joint branch. If the branches are divided into left and right spaces when branching, and the branches and flowers are not on the same plane, this kind of cyme is called scorpion-tailed cyme, such as the inflorescences of Potentilla and gladiolus. If each branch grows in one direction, it is called a spiral cyme, such as a forget-me-not inflorescence. 2. Bifidobacterium cymes are also called cymes. The flowers below the top of the main stem branch to both sides, with flowers at the top of each branch, flowers on both sides of each branch, and so on, such as curly ears, chickweed, boxwood and so on. 3. When a flower grows on the top of the main shaft of a cyme, there are more than three branches on the main shaft below the top flower, and each branch forms a small cyme, such as the inflorescence of Euphorbia helioscopia and Leonurus japonicus. The short-stalked flowers of Euphorbia helioscopia are dense and called dense cymes; Motherwort flowers are sessile and have several opposite layers, which are called cymes.