What Do Potato Leaves Look Like? A Detailed Guide

Potato plants have distinctive leaves that can help identify them. Getting to know the appearance, shape, size, texture, and other features of potato leaves provides useful information for gardeners and farmers. This article takes a close look at potato leaves to answer the question: what do potato leaves look like?

Overview of Potato Leaves

Potato plants have compound leaves, meaning each leaf is made up of multiple leaflets emerging from a central stalk. The leaves emerge alternately along the stems of the potato plant.

Some key features of potato leaves:

• Leaflets emerge from a central stalk in a pinnate pattern

• There are typically 5-9 leaflets per leaf, but can range from as few as 2 up to 18 or more.

• Leaflets are oval or oblong in shape with smooth rounded edges.

• Leaflets can be quite variable in size on the same plant, with smaller leaflets interspersed between larger leaflets.

• Leaves have short hairs (trichomes) covering the upper and lower surfaces

• Leaf color ranges from light to medium green.

• Undersides of leaves are usually lighter green than topsides.

• Veins are usually clearly visible on the undersides.

There can be considerable variation in leaf features between different potato varieties and types (diploid vs tetraploid). Next, we’ll look at these features in more detail.

Potato Leaf Structure

Potato leaves consist of multiple leaflets arranged along a central stalk called a rachis. This is referred to as a pinnate compound leaf.

Each leaflet is attached to the rachis by a small stem called a petiolule. The leaflets are arranged in pairs along the rachis, with a single leaflet at the end known as the terminal leaflet.

In most cases, there is an odd number of leaflets per leaf, typically between 5 and 9. Some potato varieties have leaves with as few as 2 or 3 leaflets, while others can have up to 18 or more. Leaves higher up on the plant often have more leaflets than lower leaves.

In addition to the larger paired leaflets, potato leaves frequently have smaller interspersed leaflets known as interjected leaflets. These help distinguish potato leaves from the leaves of related plants in the nightshade family like tomatoes.

Leaflet Size and Shape

Individual potato leaflets are oval or oblong in shape. They have a rounded tip and smooth edges without teeth or lobes. Leaflets can exhibit quite a bit of variability in size, even on the same leaf.

Larger leaflets are typically 1-3 inches long and 0.5-2 inches wide. Smaller interjected leaflets may only be 0.5 inch long. Lower leaves tend to have larger leaflets than upper leaves.

Leaflet width also varies. Some varieties have very broad leaflets while others are narrower. The terminal leaflet is often wider than the paired lateral leaflets.

Leaflet shape can range from roundish to elongated oval. Overall leaf size correlates with the vigor and maturity of the plant, with older and more robust plants having larger leaves.

Leaf Color and Texture

Potato leaf color provides clues about the plant’s health and maturity. Young emerging leaves have a light green color that darkens as they mature. Older leaves generally range from medium to dark green.

The upper surface of potato leaflets is smooth and shiny, while the underside has a duller, matte finish. The topsides are typically darker green than the undersides.

As leaves senesce later in the growing season, they lose chlorophyll and turn yellow before eventually drying up and dropping off the plant. The transition from green to yellow indicates the potatoes are maturing and nearing ideal harvest stage.

Potato leaf texture is somewhat rough and hairy. Short trichomes cover both sides of the leaflets and give them a slightly scratchy feel. These “leaf hairs” reflect light and contribute to the dull look of the undersides.

Veins and Midrib

The undersides of potato leaflets showcase a prominent network of veins. The midrib runs centrally from the base to the tip of each leaflet, with lateral veins branching off from it.

Veins are usually yellowish green to white in color and stand out vividly against the darker leaf surface. This vein pattern distinguishes potato leaves from nightshades with netted veins like tomatoes.

On the upper side of leaflets, the midrib and veins create subtle indentations but are less visually prominent than on the underside. Veins are usually more faint on larger, older leaflets than on the small interjected leaflets.

Stems and Stalks

Potato plants have angled, ridged stems that transition from smooth and thin near the top to thick and woody lower down. Mature stems are 0.25-0.5 inch thick and green to purple-brown in color.

The central rachis and petiolules that support leaflets are typically green and more slender than the main stem. Their thickness depends on maturity, with rachis of older leaves being thicker than young leaves.

Branched woody tendrils may grow from the area where leaf stalks join the stem. Aerial tubers occasionally form on above-ground stems as well, appearing as small green knobs.

Flowers

Many (but not all) potato varieties produce delicate flowers once mature. The five-petaled flowers are white, pink, purple, or blue and contain yellow anthers. They grow in clusters on upright stems rising above the plant.

Potato flowers have a star shape with fused petals 0.5-1 inch wide. The inner yellow center consists of the stamens and pistil. Flowers are short-lived, lasting only 1-3 days before dropping off.

Flowers on potato plants confirm their identity compared to related nightshades. Plus, flowering signals that tuber bulking is in progress underground.

Diploid vs Tetraploid Potatoes

There are some differences between potato leaf characteristics in diploid versus tetraploid varieties. These two main potato types have different chromosome numbers.

Diploid potatoes tend to have more leaflets (often >12), narrower leaflets, and more prominent interjected leaflets than tetraploid types. Their leaves often resemble those of wild potatoes.

Tetraploid potatoes usually have fewer leaflets (5-9), broader leaflets, and fewer or no interjected leaflets. Leaf appearance can vary widely though – some resemble diploids while others have unique shapes.

That covers the major identifying features used to answer “what do potato leaves look like.” Getting to know the details of leaf structure, shape, size, color, and texture takes some observation but becomes easier with practice. Noticing subtle differences between potato leaf types can assist with assessing plant health and growth stage.

Changes Over Time

Potato leaf features change dynamically throughout the plant’s lifecycle. Here is an overview of how potato plant leaves evolve:

• Seedlings – Cotyledons (first seed leaves) are small and rounded. First true leaves are light green with smooth, delicate texture.

• Vegetative Growth – Leaves rapidly increase in size and number. Leaflets become larger, darker green, and more hairy as plants mature.

• Flowering – Leaf growth peaks around the onset of flowering. Upper leaves may be smaller with more leaflets.

• Tuber Bulking – Lower leaves start yellowing and dropping as plants shift energy to tubers. Leaf appearance deteriorates late in season.

• Senescence – Remaining leaves turn yellow then brown. Stems weaken and collapse. Dry brown foliage can persist even after plants are long dead.

The compound leaves of potato plants have a distinct appearance. Typical features that answer “what do potato leaves look like” include:

• Multiple oval leaflets arranged pinnately along a central stalk

• Leaflets ranging from 2 to 18 or more per leaf, usually 5-9

• Interjected leaflets between larger paired leaflets

• Hairy texture and light green to dark green color

• Lighter undersides with prominent veins

• Changes over time reflecting plant maturity and tuber development

Noticing details like leaf shape, margins, veins, trichomes, and coloring takes practice but informs about plant vigor and growth phases. Comparing leaf traits between varieties can also be helpful for identification.

So next time you see leaves on an unknown plant, check for features like pinnate leaflets, hairs, and yellowish veins to determine if it could be a potato. The distinctive characteristics of potato foliage provide clues to reveal what’s growing in your garden.