Lab Work 6.docx

Lab Work 1 EXTERNAL MORPHOLOGY Table 1. Variations in the different leaf parts BASE

TIP

OUTLINE

MARGIN

VENATION

LEAF SURFACE

Decurrent

Acuminate

Linear

Entire

Parallel

Glabrous

Decurrent

Acuminate

Liner

Entire

Parallel

Glabrous

Acute

Acuminate

Ovate

Entire

Pinnately

Glabrous

Acute

Acuminate

Lanceolate

Entire

Pinnately

Glabrous

Attenuate

Spinose

Linear

Entire

Parallel

Glabrous

Rounded

Acute

Ovate

Crenate

Pinnately

Pubescent

Perfoliate

Acute

Ovate

Entire

Pinnately

Pubescent

Rounded

Obtuse

Elliptic

Entire

Pinnately

Glabrous

Oblique

Acute

Ovate

Crenate

Pinnately

Glabrous

Obtuse

Spinose

Ovate

Serrate

Pinnately

Glabrous

Cuneate

Attenuate

Elliptic

Entire

Pinnately

Glabrous

Sagittate

Acuminate

Pedate

Denticulate

Pinnately

Glabrous

Peltate

Rounded

Reniform

Crenate

SPECIMEN Saccharum officinarum (Sugarcane) Zea mays (corn) Bougainvillea spectabilis (Bougainvillea) Hedychium (Hardy ginger) Ophiopogon jaburan (Lily turf) Coleus blumei (Mayana) Pisum sativum ( Garden pea) Psidium guavaja (Guava) Hibiscus rosasinensis (Gumamela) Rosa (Rose) Citrus grandis (Suha) Ricinus communis (Castor bean) Centella asiatica (Guto Kola)

Pinnately

Table 2. Morphological features of monocot and dicot leaves CHARACTERS

MONOCOT

DICOT

Leaf stalk

Absent

Present

Leaf sheath

Present

Absent

Lamina or blade

Parallel

Reticulate

Venation

Parallel

Reticulate

Stipule

Absent

Present

Ligule

Present

Absent

Others: Leaf Appearance

Long and slender

Wide

Glabrous

Table 3. Specialization or modification in leaves SPECIMEN

LEAF MODIFICATION

SPECIALIZED FUNCTION

Allium cepa (Onion)

Bulb scale

Food storage

Aloe vera

Spine –succulent

Water and food storage

Asparagus

Cladodes

Photosynthesis

Bougainvillea spectabilis (Bougainvillea) Bryophyllum pinnatum (Katakataka) Citrus microcarpa (Calamansi) Eicchornia crassipes (Water hyacinth) Euphorbia pulcherrima (Pointsettia) Musa (Banana) Mussaenda (Doña Aurora) Nepenthes (Pitcher plant) Opuntia/Nopalea (Prickly pear) Paspalum ( Crowngrass ) Pisum sativum ( Garden pea)

Bracts

Attract pollinators

Leaflets

Reproduction

Spine

Protection

Ovate (swollen petiole)

Float in water

Bract

Pollination

Bud scale

Protect fruits

Bract

Pollination

Pitcher

Capturing prey

Spine

Water storage

Lemma

Reproduction

Tendrils

Support and climbing

ANSWERS TO QUESTIONS 1. What is a ligule? Where is it found in your specimen? Do you find it in both monocot and dicot leaves? Any taxonomic value? Ligule. (n.d.) defines a ligule as a structure which comes in a peculiar tongue-like outgrowth from the leaf surface near the leaf base. It is located in between the blade and the sheath of the leaves of the corn . Upon observation with the specimens, it was found out that ligules are only present among monocots. This structure is highly significant in identifying grasses , sugarcane as well as other monocots because of its different patterns and colors that can only be found once for every specimen.

2. Do you find compound leaves only in dicot? Why? No, compound leaves aren’t limited only in dicots rather they are also present in some monocot plants since it is a type of leaf with regards to its form which can be applied to both monocot and dicot. Palm trees and aroids are example of monocots that have compound leaves. (Bharathan, G., & Sinha, N. R. , 2001)

3. Is there a significance of compound leaves relative to strong winds? How about to leaf-eating animals? Justify your answer. Yes, there is a significance of compound leaves with regards to strong winds. As stated by Tulip Poplar. (n.d.),it can be seen from the arrangement of the leaves and their attachments that will allow them to adjust their configurations and thus reduce their exposure and flutter as the wind increases. One example of this wind-dependent reconfiguration, are the leaflets of a pinnately compound leaf such as black walnut or black locust roll up around their axial rachis . While for the leaf-eating animals, it depends upon the texture of the compound leaves .

REFERENCES Bharathan, G., & Sinha, N. R. (2001, December 01). The Regulation of Compound Leaf Development. Retrieved February 26, 2019, from http://www.plantphysiol.org/content/127/4/1533 Ligule. (n.d.). Retrieved February 26, 2019, from https://www.britannica.com/science/ligule Weak leaves deal with strong winds : Tulip Poplar. (n.d.). Retrieved February 26, 2019, from https://asknature.org/strategy/weak-leaves-deal-with-strongwinds/#.XHVWAMAzbtQ