Secretory Exogenous Tissues: Botanical Comics
Our humorous botanical cycle of preparation for professional licensing exams in pharmaceutical botany continues with a new botanical comic and a new humoresque in the style of Pavlo Glazovyi!
Secretory Exogenous Tissues: ‘The Plant’s Chemical Laboratory and Security Service’
And now, meet the masters of secretion and defense – the secretory tissues! These are the plant’s true ‘chemical plants,’ synthesizing essential oils, resins, and nectar, transforming an ordinary stem or flower into a complex system of attraction, protection, and self-cleaning. In the first part of this comic, we will examine secretory exogenous tissues, and in the second part – endogenous ones.
ABOUT PLANT ‘SECRETS‘
(In the style of Pavlo Glazovyi)
(In the style of Pavlo Glazovyi)
Ivanko walks through the garden, looking at the flowers,
But they start to make his head spin for hours!
The nectar smells so thick here, there the resin clings,
And the nettle stings him suddenly – oh, how it stings!
Our Ivanko wonders: “What miracles are these?
Something sweet, something bitter, dew flying in the breeze…”
But the plant just smiled: “I have organs of my own,
Working like factories or fountains, clearly shown!”
It’s not just for the scent or the nectar’s flow –
The secretory tissue puts on the service show!
But they start to make his head spin for hours!
The nectar smells so thick here, there the resin clings,
And the nettle stings him suddenly – oh, how it stings!
Our Ivanko wonders: “What miracles are these?
Something sweet, something bitter, dew flying in the breeze…”
But the plant just smiled: “I have organs of my own,
Working like factories or fountains, clearly shown!”
It’s not just for the scent or the nectar’s flow –
The secretory tissue puts on the service show!
Science with Character: Radix Panasovych and his Grandson Radyk Join the Fray!
Buckle up, students! We’re diving into a major section on exogenous secretory tissues, and we figured the science could use some company. To balance Professor Cortex’s academic calm, we’re bringing in some family energy!
Meet our new characters: Radix Panasovych, the wise ‘patriarch’ of the plant kingdom, and his spirited grandson, Radyk. Radix Panasovych is busy with his favorite pursuit–toughening up his grandson with the ‘grit’ of real science! Together with us, they will explore every gland and trichome on the plant’s surface. This isn’t just histology; it’s a masterclass in mentorship, where seasoned expertise meets the fresh curiosity of the next generation. Ready to see how Radix trains his grandson in the secrets of phytosecretion?
Meet our new characters: Radix Panasovych, the wise ‘patriarch’ of the plant kingdom, and his spirited grandson, Radyk. Radix Panasovych is busy with his favorite pursuit–toughening up his grandson with the ‘grit’ of real science! Together with us, they will explore every gland and trichome on the plant’s surface. This isn’t just histology; it’s a masterclass in mentorship, where seasoned expertise meets the fresh curiosity of the next generation. Ready to see how Radix trains his grandson in the secrets of phytosecretion?
External Customs
(Exogenous Secretory Structures)
“Today we shall discuss exogenous structures,” Professor Cortex solemnly announced. The student had already prepared her tablet.
“These are structures that secrete substances externally. Essentially, they serve as the plant’s cosmetics, weaponry, and perfume all at once. For licensing exams, we must know not only their appearance but also which species ‘wear’ them.”
“These are structures that secrete substances externally. Essentially, they serve as the plant’s cosmetics, weaponry, and perfume all at once. For licensing exams, we must know not only their appearance but also which species ‘wear’ them.”
“Let us begin with the most fundamental structures – the trichomes,” Professor Cortex continues. “How masterfully they conceal their aromatic treasures!”
While Professor Cortex delivers his lecture, Radix Panasovych and Radyk trek across the leaf surface as if through a wondrous forest. – “Watch your step, grandson! – Radix Panasovych exclaims. – We are among the glandular trichomes of Pelargonium. See these ‘towers’ on stalks? Each one has a globular head-pantry. That is exactly where the plant synthesizes and stores its aromatic secretion! In Pelargonium, these are glandular: they consist of a stalk and a head where the secretion accumulates. If you touch them, they break and release a characteristic aroma. They are like tiny perfume bottles placed all over the leaf.”
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETION (Essential Oil)
Caption 2: SECRETORY HEAD
Caption 3: LIVING SYRINGE (Accumulates and Secretes)
[Side Caption (Right side, with a directional arrow pointing to the base)]
Caption: EPIDERMIS (Outgrowth)
[Bottom Caption]
Caption: GLANDULAR TRICHOMES – SECRETION (Pelargonium).
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETION (Essential Oil)
Caption 2: SECRETORY HEAD
Caption 3: LIVING SYRINGE (Accumulates and Secretes)
[Side Caption (Right side, with a directional arrow pointing to the base)]
Caption: EPIDERMIS (Outgrowth)
[Bottom Caption]
Caption: GLANDULAR TRICHOMES – SECRETION (Pelargonium).
Beware! Beauty can be prickly!
Rose emergences are not just epidermal outgrowths; they are sturdy protective structures formed with the involvement of the stem parenchyma. A true biological shield! Its task is to protect the flower from unwanted guests.
[Upper Section of the Panel (Left)]
Caption: DEEP DEFENSE
[Upper Section of the Panel (Right, in a frame)]
Caption: SYRINGE-TRICHOME
[Speech Bubble (Man’s speech)]
Text: WATCH OUT! This thing pierces right through! It’s not some soft trichome!
[Middle Section (Left, with an arrow)]
Caption: Vascular root
[Lower Section (Right, under the emergence/thorn)]
Caption: It grows right from the cortex – this armor is impenetrable!
[Bottom Section (Center, with two arrows)]
Caption: Cortex/epidermis
[Bottom Caption (Below the image)]
Caption: EMERGENCE – DEEP DEFENSE (ROSA).
[Upper Section of the Panel (Left)]
Caption: DEEP DEFENSE
[Upper Section of the Panel (Right, in a frame)]
Caption: SYRINGE-TRICHOME
[Speech Bubble (Man’s speech)]
Text: WATCH OUT! This thing pierces right through! It’s not some soft trichome!
[Middle Section (Left, with an arrow)]
Caption: Vascular root
[Lower Section (Right, under the emergence/thorn)]
Caption: It grows right from the cortex – this armor is impenetrable!
[Bottom Section (Center, with two arrows)]
Caption: Cortex/epidermis
[Bottom Caption (Below the image)]
Caption: EMERGENCE – DEEP DEFENSE (ROSA).
“And this is biological weaponry,” – the professor pointed to the nettle (Urtica).
“Stinging hairs are enormous cells with a siliceous head. Upon contact, it breaks off like an ampoule, and the sharp edge injects a cocktail of histamine and formic acid under the skin. It is the perfect disposable syringe!”
[Upper Section of the Panel (In one row, left to right)]
Caption 1: STINGING HAIR (syringe)
Caption 2: SILICEOUS TIP (brittle as glass)
Caption 3: DANGER: BRITTLE TIP!
[Left Side Caption (Slightly below the upper section)]
Caption: HOLLOW CELL (syringe)
[Right Side Section (Under the broken tip and near the warning triangle)]
Caption 1 (Under the tip): SECRETION AND RELEASE
Caption 2 (By the red triangle): DANGER: BRITTLE TIP!
Caption 3 (Below the triangle): DO NOT TOUCH! (caution)
[Lower Left Section (Near the arrow pointing to the liquid)]
Caption: IRRITATING LIQUID (Histamine, Formic acid)
[Bottom Right Corner]
Caption: DANGER: CAUSTIC LIQUID!
[Bottom Caption (Below the image)]
Caption: STINGING HAIRS – DEFENSE MECHANISM (Urtica)
[Upper Section of the Panel (In one row, left to right)]
Caption 1: STINGING HAIR (syringe)
Caption 2: SILICEOUS TIP (brittle as glass)
Caption 3: DANGER: BRITTLE TIP!
[Left Side Caption (Slightly below the upper section)]
Caption: HOLLOW CELL (syringe)
[Right Side Section (Under the broken tip and near the warning triangle)]
Caption 1 (Under the tip): SECRETION AND RELEASE
Caption 2 (By the red triangle): DANGER: BRITTLE TIP!
Caption 3 (Below the triangle): DO NOT TOUCH! (caution)
[Lower Left Section (Near the arrow pointing to the liquid)]
Caption: IRRITATING LIQUID (Histamine, Formic acid)
[Bottom Right Corner]
Caption: DANGER: CAUSTIC LIQUID!
[Bottom Caption (Below the image)]
Caption: STINGING HAIRS – DEFENSE MECHANISM (Urtica)
“Plants can also be hospitable,” – Cortex continues.
“Nectaries secrete sweet syrup to attract pollinators. They can be floral (within the flower) and extrafloral – for example, on the leaf petioles of cherry. This is a kind of bribe for insects in exchange for services.”
[Upper Section of the Panel (In one row, left to right)]
Caption 1: NECTARY (secretory organ)
Caption 2: SECRETORY TISSUE
Caption 3: ATTRACTING POLLINATORS (sugar juice)
[Below “SECRETORY TISSUE”]
Caption: SECRETION
[Lower Right Section (In one row, left to right)]
Caption 1: NECTAR DROPS (carbohydrates)
Caption 2: ATTRACTING POLLINATORS (sugar juice)
[Above “ATTRACTING POLLINATORS” (With a directional arrow)]
Caption: NECTAR DROPS (carbohydrates)
[Bottom Caption (Below the image)]
Caption: NECTARIES – SECRETION (Cerasus).
[Upper Section of the Panel (In one row, left to right)]
Caption 1: NECTARY (secretory organ)
Caption 2: SECRETORY TISSUE
Caption 3: ATTRACTING POLLINATORS (sugar juice)
[Below “SECRETORY TISSUE”]
Caption: SECRETION
[Lower Right Section (In one row, left to right)]
Caption 1: NECTAR DROPS (carbohydrates)
Caption 2: ATTRACTING POLLINATORS (sugar juice)
[Above “ATTRACTING POLLINATORS” (With a directional arrow)]
Caption: NECTAR DROPS (carbohydrates)
[Bottom Caption (Below the image)]
Caption: NECTARIES – SECRETION (Cerasus).
Welcome to the Dangerous Club Nectar
On the left – Danger Zone: Histamine ‘syringes’ are at work here. One touch, and you will feel the full power of plant biochemistry.
On the right – Heavy Metal: Emergence-armor that grips the stem firmly and leaves the enemy no chance.
At the bottom – Party Center: In the nectaries, there is always sweet sugar and a queue of insects. Nature’s main attraction in action!
[Upper Section of the Panel (In one row, left to right)]
Caption 1 (Left corner): URTI-SYRINGE
Text 2 (In a jagged/starburst bubble): Oh, No! It is THE EXTERNAL ARSENAL OF SECRETION!
Caption 3 (Right corner): EMERGENCE-ARMOR
Text 4 (In a rounded bubble, slightly below the corner): Tty to bite THROUGH THE STEM TISSUES
[Middle Left Section (Interaction with the finger)]
Caption 1 (Above the finger): PAIN!
Caption 2 (Below the finger, top line): HISTAMINE!
Caption 3 (Below the finger, bottom line): KA-BOOM!
[Bottom Section (Below the leaf surface)]
Caption 1 (Signboard): NECTAR CLUB
Caption 2 (Below the signboard): SUGAR
Text 3 (In a bubble on the right): ONLY ATTRACTION here! Entrance for pollen!
On the right – Heavy Metal: Emergence-armor that grips the stem firmly and leaves the enemy no chance.
At the bottom – Party Center: In the nectaries, there is always sweet sugar and a queue of insects. Nature’s main attraction in action!
[Upper Section of the Panel (In one row, left to right)]
Caption 1 (Left corner): URTI-SYRINGE
Text 2 (In a jagged/starburst bubble): Oh, No! It is THE EXTERNAL ARSENAL OF SECRETION!
Caption 3 (Right corner): EMERGENCE-ARMOR
Text 4 (In a rounded bubble, slightly below the corner): Tty to bite THROUGH THE STEM TISSUES
[Middle Left Section (Interaction with the finger)]
Caption 1 (Above the finger): PAIN!
Caption 2 (Below the finger, top line): HISTAMINE!
Caption 3 (Below the finger, bottom line): KA-BOOM!
[Bottom Section (Below the leaf surface)]
Caption 1 (Signboard): NECTAR CLUB
Caption 2 (Below the signboard): SUGAR
Text 3 (In a bubble on the right): ONLY ATTRACTION here! Entrance for pollen!
“And now, smell the mint,” Cortex smiled. “This is where the essential oil glands are at work.”
In mint (Mentha), essential oil glands look like eight-celled shields. The essential oil accumulates under the cuticle, which swells like a bubble. This is a true freshness factory that the plant uses to repel pests.
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETORY “HEAD” (multiple cells)
Caption 2: CUTICLE (detachment)
Caption 3: “MULTICELLULAR PLANT” (complex construction)
[Middle Section (From left to right, with pointers)]
Caption 1 (Near the stalk): GLAND (multicellular)
Caption 2 (With an arrow): SECRETION (essential oil)
Caption 3 (Near the stalk): CUTICLE (detachment)
[Bottom Caption (Below the image)]
Caption: GLANDS – MULTICELLULAR SECRETORY PLANT (Mentha)
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETORY “HEAD” (multiple cells)
Caption 2: CUTICLE (detachment)
Caption 3: “MULTICELLULAR PLANT” (complex construction)
[Middle Section (From left to right, with pointers)]
Caption 1 (Near the stalk): GLAND (multicellular)
Caption 2 (With an arrow): SECRETION (essential oil)
Caption 3 (Near the stalk): CUTICLE (detachment)
[Bottom Caption (Below the image)]
Caption: GLANDS – MULTICELLULAR SECRETORY PLANT (Mentha)
The student noticed water droplets on the tips of the lady’s mantle leaves. “Is this not dew?” she asked. “No, this is guttation through hydathodes (water stomata),” Cortex explained.
When humidity is high and transpiration is impossible, the plant simply pushes out excess water through these special pores. Plant ‘sweating’.”
[Upper Section of the Panel (In one row, left to right)]
Caption 1: HYDATHODE
Caption 2: TRACHEID (pressure hose)
Caption 3: EPITHEM (sponge)
Caption 4: “GUARD” CELLS (immobile)
[Lower Left Section (Under Professor Cortex’s umbrella)]
Caption 1: XYLEM (pressure)
Caption 2 (With an arrow): XYLEM (vessel)
[Lower Right Section (Mirrored to the top caption)]
Caption: “GUARD” CELLS (immobile)
[Right Edge (Both top and bottom)]
Caption: GUTTATION (DROPLETS)
[Bottom Section (On the panel plates)]
Caption 1: HYDATHODE – “OPEN MOUTH” MECHANISM (Caltha)
Caption 2: THE DOORS ARE ALWAYS OPEN!
[Upper Section of the Panel (In one row, left to right)]
Caption 1: HYDATHODE
Caption 2: TRACHEID (pressure hose)
Caption 3: EPITHEM (sponge)
Caption 4: “GUARD” CELLS (immobile)
[Lower Left Section (Under Professor Cortex’s umbrella)]
Caption 1: XYLEM (pressure)
Caption 2 (With an arrow): XYLEM (vessel)
[Lower Right Section (Mirrored to the top caption)]
Caption: “GUARD” CELLS (immobile)
[Right Edge (Both top and bottom)]
Caption: GUTTATION (DROPLETS)
[Bottom Section (On the panel plates)]
Caption 1: HYDATHODE – “OPEN MOUTH” MECHANISM (Caltha)
Caption 2: THE DOORS ARE ALWAYS OPEN!
“And what about the scent that can be smelled from afar? Those are osmophores,” the professor said.
Osmophores are specialized areas of the epidermis that evaporate essential oils en masse. They function like powerful radio stations, broadcasting an aromatic signal for kilometers.
[Upper Section of the Panel (In one row, left to right, with arrows)]
Caption 1: SECRETION (essential oils)
Caption 2: VOLATILE COMPOUNDS (evaporation)
Caption 3: “SCENT PRODUCTION” (attracting pollinators)
[Directly below “SCENT PRODUCTION”]
Text 1 (In a surprised tone): “I CAN SMELL IT!” (surprised)
Text 2 (Repeated below): “SCENT PRODUCTION” (attracting pollinators)
[Below the previous text, with an arrow]
Caption: SECRETORY TISSUE
[Middle Section (Area of evaporation)]
Caption: SECRETION AND EVAPORATION
[On the secretory cell/oil reservoir (Showing movement to osmophores)]
Caption: SECRETION (essential oils)
[Bottom Caption (On the panel plate)]
Caption: OSMOPHORES – FRAGRANCE RELEASE (Arum).
[Upper Section of the Panel (In one row, left to right, with arrows)]
Caption 1: SECRETION (essential oils)
Caption 2: VOLATILE COMPOUNDS (evaporation)
Caption 3: “SCENT PRODUCTION” (attracting pollinators)
[Directly below “SCENT PRODUCTION”]
Text 1 (In a surprised tone): “I CAN SMELL IT!” (surprised)
Text 2 (Repeated below): “SCENT PRODUCTION” (attracting pollinators)
[Below the previous text, with an arrow]
Caption: SECRETORY TISSUE
[Middle Section (Area of evaporation)]
Caption: SECRETION AND EVAPORATION
[On the secretory cell/oil reservoir (Showing movement to osmophores)]
Caption: SECRETION (essential oils)
[Bottom Caption (On the panel plate)]
Caption: OSMOPHORES – FRAGRANCE RELEASE (Arum).
“Some plants are true predators,” – Cortex led the student to the sundew (Drosera).
Sundew leaves are covered with digestive glands on long stalks. They secrete a sticky substance containing pepsin-like enzymes. An insect gets stuck, and the glands begin the process of external digestion. Bon appétit, as they say!
[Upper Section of the Panel (In one row, left to right)]
Caption 1: PROTEOLYSIS (enzymes/proteases)
Caption 2: SECRETION AND ABSORPTION
Caption 3 (Above the red triangle): DANGER: DIGESTIVE ENZYMES!
[Middle Section (Between “PROTEOLYSIS” and “SECRETION…”)]
Caption: SECRETION AND ABSORPTION
[Lower Middle Section (With arrows)]
Caption 1 (With arrow): IRRITATING LIQUID (sugars and enzymes)
Caption 2 (Below the previous, with arrow): DIGESTIVE ENZYMES (proteases)
[Right Side Section (Near the fly interaction)]
Caption 1 (Being flooded with liquid): DANGER: CAUSTIC LIQUID!
Caption 2 (Bottom right corner): EPIDERMIS (specialized zone)
[Bottom Caption (On the panel plate)]
Caption: DIGESTIVE GLANDS – SUNDEW TRAP (Drosera).
[Upper Section of the Panel (In one row, left to right)]
Caption 1: PROTEOLYSIS (enzymes/proteases)
Caption 2: SECRETION AND ABSORPTION
Caption 3 (Above the red triangle): DANGER: DIGESTIVE ENZYMES!
[Middle Section (Between “PROTEOLYSIS” and “SECRETION…”)]
Caption: SECRETION AND ABSORPTION
[Lower Middle Section (With arrows)]
Caption 1 (With arrow): IRRITATING LIQUID (sugars and enzymes)
Caption 2 (Below the previous, with arrow): DIGESTIVE ENZYMES (proteases)
[Right Side Section (Near the fly interaction)]
Caption 1 (Being flooded with liquid): DANGER: CAUSTIC LIQUID!
Caption 2 (Bottom right corner): EPIDERMIS (specialized zone)
[Bottom Caption (On the panel plate)]
Caption: DIGESTIVE GLANDS – SUNDEW TRAP (Drosera).
“And finally – salt glands,” the professor concluded.
“In plants like tamarisk, salt glands remove excess salts from the tissues. A salt crust even appears on the leaves. Now you are almost ready for the licensing exam! From trichomes to salt glands – you know the entire system of exogenous secretions.”
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETORY HEAD
Caption 2: SALT COLLECTOR
[Upper Right Corner (Above and below the red triangle)]
Caption 1 (Above the triangle): DANGER: SALT CRYSTALS!
Caption 2 (Directly below the triangle): DANGER: HIGH SALT CONCENTRATION!
[Directly below the previous text, with an arrow]
Caption: EPIDERMIS
[Middle Section (Between “SECRETORY HEAD” and “SALT COLLECTOR”)]
Caption: SECRETION AND ACCUMULATION
[Lower Section of the Panel (In one row, left to right)]
Caption 1: SALT CRYSTALS (excess)
Caption 2: SALT COLLECTOR
Caption 3: DRAINING EXCESS SALT (extreme!)
[Bottom Caption (On the panel plate)]
Caption: SALT GLANDS – EXTREME EXCRETION (Salicornia).
[Upper Section of the Panel (In one row, left to right)]
Caption 1: SECRETORY HEAD
Caption 2: SALT COLLECTOR
[Upper Right Corner (Above and below the red triangle)]
Caption 1 (Above the triangle): DANGER: SALT CRYSTALS!
Caption 2 (Directly below the triangle): DANGER: HIGH SALT CONCENTRATION!
[Directly below the previous text, with an arrow]
Caption: EPIDERMIS
[Middle Section (Between “SECRETORY HEAD” and “SALT COLLECTOR”)]
Caption: SECRETION AND ACCUMULATION
[Lower Section of the Panel (In one row, left to right)]
Caption 1: SALT CRYSTALS (excess)
Caption 2: SALT COLLECTOR
Caption 3: DRAINING EXCESS SALT (extreme!)
[Bottom Caption (On the panel plate)]
Caption: SALT GLANDS – EXTREME EXCRETION (Salicornia).
The Exogenous Arsenal, or Why You Shouldn’t Poke Everything You See
(A humorous guide to external secretory tissues)
A student reached for roses, growing by the wall,
To study secretory tissues and give science his very all.
But hidden in the shadows, a nettle stood so tall –
‘Ouch! A stinging syringe got me! I didn’t see it at all!
The Professor laughed out loud: “That’s an urti-trichome, son!
It’s filled with histamine and thinks that stinging you is fun!
And if you want to touch the armor – the emergence on the stem –
Prepare for fiery biochemistry! You’re not ready for that gem!”
The student puffed upon his fingers: “Where are the treats you promised?
Where are the tasty nectaries? Let’s be perfectly honest!”
Cortex pointed to the ‘Nectar Club’ hidden down below:
“There’s a queue of flies; don’t trip or let your teardrops flow!”
“Those digestive glands are traps for fools, catching every guest,
While salt glands sweat out crystals, putting halophytes to the test…
The lesson here is simple, timely, and quite wise:
The exogenous arsenal is a defense in clever disguise!”
The Professor winked: ‘This lab is done, the secrets are revealed,
From every glandular hair to the armor in the field!’
To study secretory tissues and give science his very all.
But hidden in the shadows, a nettle stood so tall –
‘Ouch! A stinging syringe got me! I didn’t see it at all!
The Professor laughed out loud: “That’s an urti-trichome, son!
It’s filled with histamine and thinks that stinging you is fun!
And if you want to touch the armor – the emergence on the stem –
Prepare for fiery biochemistry! You’re not ready for that gem!”
The student puffed upon his fingers: “Where are the treats you promised?
Where are the tasty nectaries? Let’s be perfectly honest!”
Cortex pointed to the ‘Nectar Club’ hidden down below:
“There’s a queue of flies; don’t trip or let your teardrops flow!”
“Those digestive glands are traps for fools, catching every guest,
While salt glands sweat out crystals, putting halophytes to the test…
The lesson here is simple, timely, and quite wise:
The exogenous arsenal is a defense in clever disguise!”
The Professor winked: ‘This lab is done, the secrets are revealed,
From every glandular hair to the armor in the field!’
🎭 The Moral of the Humoresque
So, listen well, dear students, to this simple law of life:
Exogenous tissues are armor, sharp as any knife!
Emergences and urti-hairs will sting and strike and bite,
While nectaries invite the bees to a banquet of delight!
He who knows these tricks of old won’t prick his fingers sore,
For he learned his Botany well – and knows the nature’s lore!
So, listen well, dear students, to this simple law of life:
Exogenous tissues are armor, sharp as any knife!
Emergences and urti-hairs will sting and strike and bite,
While nectaries invite the bees to a banquet of delight!
He who knows these tricks of old won’t prick his fingers sore,
For he learned his Botany well – and knows the nature’s lore!