Tendril:- A climbing organ, often thread-like and coiling around supports, branched or unbranched.
Tepal:- A division of the perianth of a flower having a virtually indistinguishable calyx and corolla, as in tulips and lilies.
Terete:- Circular in cross section.
Terminal:- At the end. The furthest point.
Ternate:- Arranged in a whorl or cluster of three
Tessellated:- Chequered, having veins in squares or rectangles
Testa:- The outer coat of the seed
Thorn:- A stiff woody structure, generally pointed and formed from a modified stem.
Throat:- The opening to a tubular or funnel-shaped flower.
Thyrse:- 1) A mixed inflorescence with the main axis a raceme and secondary axes in the form of cymes; 2) A compact panicle of ± cylindrical form
Thyrsiform:- Shaped like a thyrse
Thyrsoid:- Like a thyrse
Tomentose:- Densely covered in short soft, matted hairs.
Tomentum:- A felt-like covering of downy hairs
  Refers to leaf or petal margins that are toothed (ser­rated).
Torulose/Torose:- Cylindrical with ridges or swellings
Tricuspidate:- With three short sharp points
With three leaflets.
Trifurcate:- Split into three equal branches
Trigonous:- Obtusely 3-angled
Tripinnate:- Having bipinnate leaflets or lobes that are themselves pinnately divided.
With three sharp angles.
Trullate, Trulliform:- Trowel-shaped, shaped like a bricklayers trowel
Truncate:- Ending abruptly - as if cut off. in more or less a straight line,
A fused, often cylindrical, part of a calyx or corolla.
Tuber:- A swollen underground organ, developed from under­ground stems or sometimes from the roots
Tunic:- Fibrous covering of the corm. Any loose membranous skin not formed from epidermis.
Tunicate:- With sheathing. concentric layers
Tunicated bulb:- A bulb covered with concentric enveloping coats (as in an onion)
Tuberculate:- With small, wart-like projections.
Turbinate:- Top-shaped. obconical and narrowed towards the point
Turgid:-Swollen and distended or congested