THE SHAPE OF LEAVES

Design and InstallationGarden Caregarden TriviaIndoor plantsLighting and IrrigationPlant Health CareUncategorized
Written By Peter Morris

What is a leaf?

 A leaf is the main organ attached to the stem.  It is specialized for photosynthesis. Over time, it has evolved into a plethora of different shapes, sizes and characteristics. These vary considerably depending largely on their adaptation to climate.Leaves have also adapted to the available sunlight, presence of grazing animals, available nutrients, and competition from other plants. Taxonomists use all these different characteristics to classify plants - and every characteristic has a specific name.

Beware - this name giving thing is daunting!

Typical leaf

 

Parts of a leaf

 Leaves and stems together are called “shoots”.  We call both together “foliage”.  A leaf blade is called “lamina” . The top side is “adaxial”, lower is “abaxial”.  Broad flat leaves are known as “megaphylls" (Hosta).  Plants with small leaves - “microphylls” (Boxwood). 

Megaphyll

 

Microphyll

 Leaves attached to stems by stalks (petioles) are called “petiolate” (Birch).  Those that have no attachment, or if attached directly - “sessile” (Iris).

A petiolate leaf

 

Sessile leaves

 

Leaf Margins

 

A few common (but not all !) names of leaf margins

 

Arrangement on the stem

 The most common arrangement of the leaf on the stem is either "alternate” (Sweetgum), or "opposite" (Maple).  Less common are “basal”, “cauline”, “verticillate”, “rosulate”, or “in rows”. 

Leaf shapes

 The blade (lamina) can be "simple" (Hibiscus) or "compound" (Rose).  Compound leaves are further broken into “palmately compound”, “pinnately compound, “odd pinnate”, “even pinnate”, “bi pinnately compound”, “trifoliate”, or “pinnatifid”. Take a look at all the leaf shape classification in the table below ! 

Common names of leaf shapes

And yes – I did study all of these names when taking my Taxonomy classes !

 

More Classifications

 Specific names exist for particular shapes of petioles.  Also for leaf margins, leaf venation, how pronounced is the venation, the shape of leaf tips, the shape of the base of the leaf, or the surface of leaf.  Even how hairy, or if it's a young or old leaf !

OMG ! 

So many classifications !

 

My classification of this Begonia rex leaf is “pretty” what about you !

 

So don't worry if your gardener tells you your tree has Palinactodromous leaves

 

– it just means the leaf veins branch beyond the primary split - all good!

 

Call Plant Specialists today and have us put some leaves in your garden.

( with the plants of course! )

Don't delay – the sooner the better !

  

GREENING NEW YORK FOR OVER 51 YEARS !

   Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBAAll photographs used with permission @SHUTTERSTOCK 

Peter Morris

Peter was born and raised on a beautiful green island in the midst of a tropical rainforest. He was introduced into the world of plants at the age of six when his grandmother, an avid Spanish gardener herself, asked him to help her grow seeds for her pepper garden. He was hooked! By the time he was a teen, he had his own rose and orchid collection numbering in the hundreds. Botany was in his blood, and that is what he set out to study.

His passion brought him to NY in the late seventies to further his education. His tenacity allowed him to work full time at Plant Specialists while he completed a MS in Plant Biology. As a manager at the time he felt unsatisfied with his knowledge of business and business processes. Peter felt compelled to learn, so he then pursued and completed an MBA in Quality Management within a few short years.

Peter’s other passion is teaching. His natural ability is quickly consumed by our staff in all subjects in Botany, Horticulture, and Landscaping. He created an immense reference library of more than 3,500 plants providing an invaluable resource for our staff.

Peter’s breadth of knowledge and wisdom allows him to effectively diagnose the needs of plants. Sometimes just by walking into a garden he can create a prescription that fixes even the hardest issue. He is our Staff Botanist, Diagnostician, and all around Mentor. Recently, he has put his immense knowledge and skills into developing a new department that focuses on Plant Healthcare. As he puts it, “Magic through Science”. The PHC staff that surround him have avidly consumed his teachings. Substantially developing their own plant wisdom, many have taken on difficult plant health issues with spectacular results.

Plant Healthcare has been an instant success with customers! The proper treatment of insects and diseases including Organic methods has made pest control a necessity for every plant. Correcting hormonal imbalances caused by planting in containers or refurbishing soils leached of nutrients by irrigation systems are big challenges PHC has become quite comfortable addressing. The scientific approach to the complex demands of keeping plants healthy in our harsh city environment has made many a customer say WOW!

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