Angiosperms (flowering plant) include in phylum Anthophyta. Angiosperms are plant that have flowers and fruit. Their part of the flower is a carpel which surrounds and protects the ovules and seeds. The fruit surrounds the embryo and aids seed dispersal. The great majority of angiosperms are classified either as monocots or eudicots. Monocot embryos have a single seed leaf (cotyledon), and pollen grains with a single groove while eudicots (true dicots) have two cotyledons, and pollen grains with three groove.
Monocotyledons have leaf lamina with parallel vein. Their sepal, petal arranged in a series of 3s with adventitious root system only. Their vascular bundles scattered in cortex or irregular arrangement and they have no secondary development (non-woody and no annual rings). Whereas, dicotyledons have leaf lamina with netted vein. Their sepal, petal arranged in a series of 2, 4 or 5 with primary and adventitious root system. They have secondary growth in stem and vascular bundles extended via cambial activity (formation of ‘annual ring’ in cross section)
Based on the experiment diversity of angiosperms, the fixed slides is observed under light microscope, fresh specimens under direct observations, stereomicroscope and living specimens under direct observation with zero magnification. We will explore several fixed and fresh specimens of some selected angiosperms. Fixed slides under light microscope contributed by Helianthus sp, Hibiscus sp. , Monocots stem (Monocotyledoneae), Dicots root (Dicotyledoneae), Monocots root (Monocotyledoneae), Triticum sp. oot tip (‘wheat’, Monocotyledoneae), Capsella sp. carpel (Monocotyledoneae), Dicot leaf (Dicotyledoneae), Monocot leaf (Monocotyledoneae), Zea mays leaf (‘maize’, Monocotyledoneae),Fresh specimens under direct observation involved Vigna radiata Seedling and Sapling (‘kacang hijau,Dicotyledoneae), Zea mays Seedling and Sapling (‘jagung’,Monocotyledoneae),Crinum asiaticum Inflorescence (‘lily’,Monocotyledoneae),Bougainvillea sp. Inflorescence (‘bunga kertas’,Dicotyledoneae),Allamanda cathartica Flower (‘golden trumpet’,Dicotyledoneae), Ixora sp.
Inflorescence (‘bunga jejarum’,Dicotyledoneae),Mimusops elengi Fruit (‘bunga tanjung’,Dicotyledoneae),Nephelium lappaceum Fruit (‘rambutan’) and Veitchia merrilli (‘manila palm’,Monocotyledoneae). Then, we can observe and labeled the important structures of particular specimens prepared for us such as for Helianthus sp. stem,we need to observe the cross-section anatomy of the stem and for Tricum sp we observed the longitudinal-section anatomy of the root tip. While,Zea mays leaf, we are observed the surface anatomy of the leaf abaxial.
Seedling and sapling is used for Vigna radiata and Crinum asiaticum as well as Bougainvillea sp. inflorescence is observed for the whole compound of flower such as flower stalk,petaloid leaves,calyx,filament,anther and carpel.. Allamanda cathartica, we need to label the free calyx and the fused corolla. Ixora sp, we observed the umbel inflorescence and for Mimusops elengi, the persistent calyx and stigma. Then, the persistent stigma, the pericarp, the aril and the seed is labeled for Nephelium lappaceum. Next, for Veitchia merrilli, we observed the whole fruit such as the dissected fruit with pericarp, aril and seed.
We were able to illustrate the whole or some parts of the specimen representing certain structures as intended by the accompanying instructions. For example to illustrate the structures of Helianthus sp, Hibiscus sp. ,Crinum asiaticum Inflorescence (‘lily’,Monocotyledoneae),Allamanda cathartica Flower (‘golden trumpet’,Dicotyledoneae), Ixora sp. Inflorescence (‘bunga jejarum’,Dicotyledoneae),Mimusops elengi Fruit (‘bunga tanjung’,Dicotyledoneae),Nephelium lappaceum Fruit (‘rambutan’) and Veitchia merrilli (‘manila palm’,Monocotyledoneae). We need to know the structures shown clearly with the correct labeling.
Next, we were able to describe the common characteristics and diagnostic characteristics of Angiosperms. The diagnostic characteristics are based on monocotyledons and dicotyledons,presence of kernel, germination seedling and sapling, has persistent stigma, persistent calyx, has umble inflorescence, has hypocotyls and epicotyls,axillary position on branch, has petaloid leaves, hairy and erect stem and fused corolla. For common characteristics, monocotyledons consist of Triticum sp, Zea mays, Crinum asiaticum and Veitchia merrilli. Whereas, dicotyledons, like, Helianthus sp, Hibiscus sp. , Capsella sp. Vigna radiata, Bougainvillea sp. , Allamanda cathartica, Ixora sp, Mimusops elengi and Nephelium lappaceum. Only Ixora sp. has umble inflorescence and only Triticum sp. and Zea mays have kernel for monocotyledons. Seedling and sapling includes Zea mays and Vigna radiata. Last but not least, we were also able to construct taxonomic key based on the common characteristics and diagnostic characteristics of Angiosperms. Commonly used was dichotomous key which was consist of each choice (‘pointer’) within a pair of conflicting choices (‘couplet’) and in this experiment we use bracketed key.