Botanical characteristics of small seed Coffee

1. Root

Coffee is a shallow root crop, and the plants propagated by seeds are conic roots. From the point of view of varieties, the roots of small and medium grain species are shallow, while those of large grain species are deeper. Yunnan small grain coffee is a 3-year-old 4-year-old fruit tree with a deep main root of about 70cm. The lateral root that grows horizontally from the main root is called the horizontal lateral root, the vertical lateral root grows downward, and the root extracted from the lateral root is called the secondary lateral root and the tertiary lateral root respectively. The root system of coffee has an obvious layered structure, which is usually one layer per 5cm, but most of the absorbing roots are distributed in the 0-30 cm soil layer. The regeneration ability of coffee root system is strong.

2. Stem

The stem of coffee is erect, the tender stem is slightly square, green, cork is round and brown. Small seed coffee stem internodes long 4~7cm, a group of leaves growing on each node, leaf axils with overlapping buds, called upper buds in the upper, lower buds in the lower. The upper bud develops into a branch and the lower bud develops into a straight branch. The upper bud and the lower bud sprout at the same time.

The growth of coffee trunk has obvious apical advantage. The branches near the top of the trunk grow particularly vigorously. But this advantage weakens with the increase of the trunk. If the trunk is allowed to grow naturally, all kinds of coffee can continue to grow according to its growth power. The small, medium and large seeds can reach 46.6 meters, 66.8 meters and more than 10 meters respectively.

The growth of the trunk varies seasonally. The dry season growth is small, the Internode is short; in the rainy season, the growth is large, the Internode is long; in winter, the growth is the smallest, the Internode is the shortest, and dense nodes appear. According to its growing position and growth direction, the branches of coffee can be divided into the following categories: first branch, second branch, third branch, secondary branch and direct branch.

Third, leaves

The leaves of coffee are opposite, usually spreading in two rows and individual in a single whorl. Petiole short, leaf blade leathery, green. Glossy, oval to long oval. The leaf size of small seed coffee is relatively uniform, the leaf is small and the end is longer, the leaf edge wave is obvious, the length is about 12~16cm, the width is about 5~7cm. The leaves of coffee trees are typical ventral dorsal symmetries. The leaves contain tannins, starch grains and calcium oxalate.

4. Flowers

Several to dozens of flowers are clustered in leaf axils, every 2 to 5 flowers grow on a flower axis, pedicels short, flowers white, fragrant. The petals of medium and small seeds are generally 5. The base of the petals are connected in a tubular shape, forming a high-footed butterfly-shaped Corolla. Stamens are generally as many as petals, inserted in the throat of Corolla. The anthers are two-loculed at both ends of the filaments, forming a "d" shape. Pistil style filiform, stigma bifid, ovary inferior, usually two-loculed. There is an anatropous ovule on the central placenta of each locule, and the base of the stalk is short. Insect-pollinated flowers, large-grain species and small-grain species can self-pollinate, while medium-grain species are mostly cross-pollinated.

Coffee is a short-day plant. Coffee has the characteristics of multiple flowering and concentrated florescence. The florescence of small seed coffee in Yunnan (Dehong Dai Jingpo Autonomous Prefecture) is from February to July, and the flowering period is from March to May. The flowering of coffee is greatly affected by climate, especially rainfall and temperature. Coffee flowers have a short life span of only 2-3 days. Small seed coffee usually opens at 3: 5 in the morning and blooms from 5 to 7 o'clock.

5. Fruit

The fruit is a berry. Oval, 9mm long, young fruit green, red and purplish red when mature. Each fruit generally has two seeds, showing a semi-oval shape, with a longitudinal groove, called grooves.

The development time of coffee fruit is longer. It takes 8 to 10 months for small seed coffee (to mature from October to December of the year), 10 to 12 months for medium seed coffee (from November to May of the following year), and 12 to 13 months for large seed coffee. Rainfall has a great influence on fruit development, and climatic conditions directly affect fruit development.