![]() (ii) In some aquatic plants (Lemna, Spirodela, Wolffia) the reduced discoid stem is green and flattened to float on the surface of water. Leaves are crowded together on these stems. (i) A reduced green discoid stem occurs in the vegetative phase above the base of root in Radish, Carrot, Turnip, etc. A leafless shoot bearing flowers is called scape, e.g., onion, aroids, banana. In a few monocots with underground stems, aerial shoots develop only for bearing flowers. ![]() It has hollow internodes and solid prominent nodes. The un-branched erect, stout cylindrical stem having scars and remnants of fallen leaves is called caudex. Erect upright aerial stem may be branched or un-branched. Stem may be aerial, sub-aerial or underground. The axis is multipodial, e.g., Euphorbia helioscopia, E. 5.27 B):Īfter stoppage of growth by a terminal bud, growth is continued by a whorl of three or more axillary branches. ![]() Karonda), Mirabilis jalapa (Four O’ Clock). The axis is multipodial, e.g., Viscum (Mistletoe), Silene, Carissa carandas (vern. Dichotomous branching is rare in angiosperms, e.g., Asclepia syriaca, Pandanus (Screw pine), Hyphaene (a palm).Īfter the stoppage of growth or modification of the terminal bud, further growth is continued by two axillary branches. 5.25 A) the growing point gets divided into two in the region of branching, e.g., Dictyota (an alga), Marchantia (a bryophyte). Dichotomous branching is quite rare in angiosperms. Branching of the stem is of two types, dichotomous and lateral. Un-branched stem is called caudex or columnar, e.g., Palm, Sugarcane, Maize. (xi) Stems are usually positively phototropic, negatively geotropic and negatively hydrotropic. ![]() (x) Hair, if present, are commonly multicellular. (ix) Stem exposes leaves, flowers and fruits to their most suitable position in the aerial environment for optimum function, (viii) Leaves and stem branches develop exogenously. (vii) In the mature state it bears flowers and fruits, (vi) The young stem is green and capable of performing photosynthesis, It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tisthati "stands " Avestan histaiti "to stand " Persian -stan "country," literally "where one stands " Greek histēmi "put, place, cause to stand weigh," stasis "a standing still," statos "placed," stylos "pillar " Latin sistere "stand still, stop, make stand, place, produce in court," status "manner, position, condition, attitude," stare "to stand," statio "station, post " Lithuanian stojuos "I place myself," statau "I place " Old Church Slavonic staja "place myself," stanu "position " Gothic standan, Old English standan "to stand," stede "place " Old Norse steði "anvil " Old Irish sessam "the act of standing.(v) The stem nodes possess dissimilar appendages called leaves, It forms all or part of: Afghanistan Anastasia apostasy apostate armistice arrest assist astatic astatine Baluchistan bedstead circumstance consist constable constant constitute contrast cost desist destination destine destitute diastase distance distant ecstasy epistasis epistemology establish estaminet estate etagere existence extant Hindustan histidine histo- histogram histology histone hypostasis insist instant instauration institute interstice isostasy isostatic Kazakhstan metastasis obstacle obstetric obstinate oust Pakistan peristyle persist post (n.1) "timber set upright " press (v.2) "force into service " presto prostate prostitute resist rest (v.2) "to be left, remain " restitution restive restore shtetl solstice stable (adj.) "secure against falling " stable (n.) "building for domestic animals " stage stalag stalwart stamen -stan stance stanchion stand standard stanza stapes starboard stare decisis stasis -stat stat state (n.1) "circumstances, conditions " stater static station statistics stator statue stature status statute staunch (adj.) "strong, substantial " stay (v.1) "come to a halt, remain in place " stay (n.2) "strong rope which supports a ship's mast " stead steed steer (n.) "male beef cattle " steer (v.) "guide the course of a vehicle " stem (n.) "trunk of a plant " stern (n.) "hind part of a ship " stet stoa stoic stool store stound stow stud (n.1) "nailhead, knob " stud (n.2) "horse kept for breeding " stylite subsist substance substitute substitution superstition system Taurus understand. *stā-, Proto-Indo-European root meaning "to stand, set down, make or be firm," with derivatives meaning "place or thing that is standing."
0 Comments
Leave a Reply. |