Hemp (Cannabis sativa L.) is a remarkable plant with a rich history of cultivation for its diverse applications. Understanding its botanical characteristics is key to appreciating its versatility and distinguishing it from other cannabis varieties. This document outlines the primary botanical features of industrial hemp.

Classification and Growth Habit

Hemp belongs to the Cannabaceae family, which also includes hops. It is an annual herbaceous plant, meaning it completes its life cycle within one growing season. Hemp typically grows as a tall, slender plant with a single main stalk, especially when cultivated densely.

Characteristic	Description
Family	Cannabaceae
Genus	Cannabis
Species	Cannabis sativa L.
Life Cycle	Annual herbaceous plant
Growth Form	Typically tall and slender, single main stalk

Stem Characteristics

The stem of the hemp plant is fibrous and hollow, particularly in the internodes (the sections between nodes). The strength and length of these fibers are highly valued for various industrial uses, including textiles, paper, and construction materials.

• Structure: Hollow internodes, solid nodes.
• Color: Green, often with reddish or purplish hues as it matures, especially in response to environmental conditions.
• Fibers: Contains bast fibers (outer layer) and hurds or shives (inner woody core).

Leaf Morphology

Hemp leaves are compound and palmate, meaning they are divided into several leaflets that radiate from a central point, similar to the fingers on a hand. The number and shape of these leaflets can vary.

• Arrangement: Opposite on the lower part of the stem, becoming alternate higher up.
• Leaflets: Typically 5 to 9 leaflets per leaf, though immature plants or specific cultivars may have fewer. Each leaflet is serrated (toothed) along its edges.
• Surface: Often rough to the touch due to small, stiff hairs (trichomes).

Root System

Hemp develops a strong taproot system, which can penetrate deep into the soil. This characteristic makes hemp beneficial for soil structure improvement and nutrient cycling.

• Type: Taproot, with numerous lateral roots.
• Depth: Can reach depths of 2-3 meters (6-10 feet) or more, depending on soil conditions.
• Benefits: Helps prevent soil erosion, improves soil aeration, and can retrieve deep-seated nutrients.

Floral Characteristics

Hemp is typically dioecious, meaning individual plants are either male or female, producing separate male and female flowers. Monoecious varieties (plants with both male and female flowers on the same plant) also exist. The appearance of the flowers differs significantly between sexes.

• Male Flowers:
  • Appearance: Small, yellowish-green, borne in loose, branched clusters (panicles).
  • Function: Produce pollen.
  • Location: Primarily on the upper parts of the plant.
• Female Flowers:
  • Appearance: Small, greenish, forming tight clusters (glomerules) in the leaf axils. They have distinctive pistils (stigmas) that are often white or reddish and appear hairy or wispy.
  • Function: Produce seeds after pollination.
  • Location: Clustered along the main stem and branches.

Seed Characteristics

Hemp seeds, often called "hemp hearts" when hulled, are technically achenes (a type of dry fruit). They are highly nutritious and are used for food, oil, and various other products.

• Size: Small, typically 2-4 mm in diameter.
• Color: Shiny, mottled gray, brown, or black.
• Composition: Rich in essential fatty acids (omega-3 and omega-6), protein, and fiber.

Cannabinoid Content

A critical distinction for industrial hemp is its low tetrahydrocannabinol (THC) content. Legally, industrial hemp must contain less than 0.3% THC on a dry weight basis, ensuring it is non-intoxicating. While low in THC, hemp is often rich in other cannabinoids, such as cannabidiol (CBD).

• THC: Typically below 0.3% (dry weight).
• CBD: Varies significantly by cultivar; some are bred to be high in CBD.
• Other Cannabinoids: Contains a wide array of other minor cannabinoids, terpenes, and flavonoids that contribute to its unique chemical profile.