Stems serve both supportive and conductive functions for plants. They develop from the epicotyl of seeds and connect other plant organs like leaves, flowers, and fruit. Stems can be modified for storage, protection, or propagation. Some common modified stems include rootstocks, bulbs, corms, caudices, rhizomes, stolons, cladodes, and tubers. Rootstocks like bulbs, corms, and caudices remain underground during harsh conditions. Rhizomes are horizontal underground stems while tubers are thick underground storage stems lacking scales. Stolons are stems that propagate horizontally just below the soil surface.

1. Stems Presented by : Geonyzl L. Alviola

2. Stem Function for both supportive organs and conductive organ It is a shoot associated with other plant organs like leaves, flower, fruit It develops from the epicotyl of the embryo (in the seed)‏

3. Review on the parts of the plants: 1. Leaf primordium = an immature leaf of the shoot.

4. 2. Node = the point of attachment of a leaf to a stem

5. 3. Internode = the region between two adjacent nodes

6. Stem types

7. Modification of the stem would depend on the need of the plant to survive… … like the animals it learns how to adapt .

8. Stem modifications for storage and protection a. rootstock = a general term for an underground stem or shoot that later will give rise to aerial shoot. = remain alive underground during harsh condition

9. Different types of Rootstock Bulb – consist of small amount of vertical stem and a massive quantity of thick, fleshy storage leaves. - most of them consist of concentric rings of scales attached to a basal plate.

12. Other bulbous plants Daffodil Reticulate iris

13. 2. Corm - formed from a swollen bases of stems. - A corm consists of one or more internodes with at least one growing point.

15. Examples of Corm Crocuses Gladioli

16. 3. Caudex = the rootstock consist of a relatively undifferentiated but vertically oriented stem. = generally called “fat plants” Adenium obesum – family Apocynaceae (a relative of Calachuchi)‏

17. Other caudiciform plants Ibervillea Trochomeria

18. 4. Rhizome= the stem is horizontal and underground with short internodes and bearing with scale-like leaves ginger

19. Other rhizome plants Johnsongrass Sorghum halepense Cogon grass Imperata cylindrica

20. 5. Tuber = a thick under ground storage stem, usually not upright = bearing outer buds = lacking protective scales

21. Main plant parts are: haulm (foliage), tubers and roots.

22. Other Types of Stems Stolon / runner = with long internodes just below the surface of the ground that typically terminating in a new plant = use for propagation

23. Plants with stolon

24. Bermuda grass ( Cynodon dactylon ).

25. Cladode = resemble like a leaf = a photosynthetic stem = flatten in appearance = reduce water loss

26. Thorn – is a sharp pointed stem. - serve as protective structure of the plant.

27. Scape = “naked” , lacking vegetative leaves = generally arising from basal rosette of vegetative leaves = the stem-like, flowering stalk of a plant with radical or rosulate leaves.

28. Primula vulgaris Primula eliator

29. Culm = refers to the flowering and fruiting stems.

30. Tiller = are segmented, each possessing two part leaf = involve in vegetative propagation

32. Pseudobulb = short erect aerial storage or propagative stem

33. Stem Habit Describing the relative position of the stem or shoot. 1.Caulescent – a plant with above ground stem. upright aerial stem with the leaves arising from all or some of the nodes on the above-ground stems

34. 2. acaulescent – plants that bear photosynthetic leaves at ground level. Yucca

35. 3. Frutescent = a shrub with n umerous woody, aerial trunks Mimosa

36. Arborescent- tree like in appearance and size.