acc	        name	                ***	term_definition
PO:0001000	meristem eloboration	***	OBSOLETE. the root meristem gets organized
PO:0001002	fruit development stages	***	Stages of development of a fruit defined by characteristic morphological, structural, histological or other visible features.
PO:0001003	formation of the leaf founder cells	***	The initial stage of leaf development  where cells in the SAM are already determined to form a leaf primordium, but the primordium itself is not distinguishable morphologically.
PO:0001004	anther developmental stages	***	Stages of development of the anther defined by characteristic morphological, cytological, histological or other visible features.
PO:0001005	A archesporial cells visible	***	An initial stage during which archesporial cells arise in four corners of L2 layer. Change in shape of primordia to more oval.
PO:0001006	B enlarged microsporocyte stage	***	Stage during which the microsporocytes become conspicuous.
PO:0001007	pollen developmental stages	***	Stages of development of the pollen defined by characteristic morphological, cytological, histological or other visible features.
PO:0001008	C callose wall formation in pollen mother cells	***	Stage during which diploid pollen mother cells become separated from each other and from tapetum by a callose wall.
PO:0001009	D pollen mother cell meiosis stage	***	Stage during which pollen mother cells undergo meiosis to form tetrads of microspores.
PO:0001010	F microspore release stage	***	Stage of microgametophyte development during which the callose wall between the tetrads breaks down and haploid microspores are released and lie freely in locules.
PO:0001011	A microsporogenous mass stage	***	An initial stage during which the archesporial cells divide to give rise to primary parietal and sporogenous cells.
PO:0001012	G early unicellular microspore stage	***	Stage of microgametophyte development during which the microspores round up and small vacuoles appear in their cytoplasm.  The microspore walls thicken due to the formation of the exine.
PO:0001013	H late unicellular microspore stage	***	Stage of microgametophyte development during which a large vacuole is formed in each microspore causing a rapid increase in size and a displacement of the nucleus to one side.
PO:0001014	I first mitotic division stage	***	Stage of microgametophyte development during which the asymmetric, first mitotic division of the microspores occurs producing a large vegetative cell and small generative cell, located near pollen wall.
PO:0001015	K second mitotic division stage	***	Stage of microgametophyte development during which the generative cell undergoes mitotic division to form two male gametes, the sperm cells.
PO:0001016	L mature pollen stage	***	Stage of microgametophyte development during which the pollen reaches mature stage and desiccates.
PO:0001017	M germinated pollen stage	***	The final stage in the life cycle of the male gametophyte. Upon rehydration, mature pollen grain forms a tubular outgrowth, the pollen tube, which carries the male gametes.
PO:0001018	B formation of primary parietal and sporogenous cells	***	Stage during which the primary parietal and  primary sporogenous layers are derived from archesporial cells.
PO:0001019	formation of leaf primordium	***	Stage of leaf development  when leaf primordium is formed as a small protrusion on the flank of SAM.
PO:0001020	hood-shaped primordium	***	Stage of leaf development  when a hood-shaped  primordium is formed, partially enclosing P1 and SAM, as in Poaceae.
PO:0001021	formation of ligule primordium	***	Stage of leaf development  when conical P3 leaf completely encloses SAM, and the ligule primordium is visible, as in Poaceae.
PO:0001023	rapid elongation of leaf blade	***	Stage of leaf development  during which a rapid elongation of the leaf blade occurs; the elongation of the leaf sheath has not started, as in Poaceae.
PO:0001024	rapid elongation of leaf sheath	***	Stage of leaf development  during which a rapid elongation of the leaf sheath occurs, as in Poaceae.
PO:0001025	C four anther lobes formed	***	Stage during which the four-lobed anther pattern with two developing stomium regions (notch) are formed.
PO:0001026	D locules established	***	Stage during which the four clearly defined locules are established. All anther cell types present and microspore mother cells appear.
PO:0001027	meristamtic zone formation	***	OBSOLETE. The meristematic zone is formed
PO:0001028	elongation zone formation	***	OBSOLETE. The cells of root primordium undergo elonagtion
PO:0001029	E tetrad stage	***	Stage immediately following meiosis, during which the tetrads of microspores are still hold together, enclosed by the callose wall.
PO:0001030	specialization zone formation	***	OBSOLETE. The cells develop their characteristic morphology.
PO:0001031	4 root elongation	***	The stage at which root is elongating.
PO:0001032	E tapetum degeneration initiated	***	Stage during which degeneration of the tapetum is initiated, as the deposition on the surface of the microspore primexine proceeds.
PO:0001034	F bilocular anther stage	***	Stage during which anther becomes bilocular, after degeneration and breakage of septum below stomium.
PO:0001035	G anther dehiscence	***	Stage during which the dehiscence of anthers occurs. Anther breaks along stomium and pollen is released.
PO:0001036	H anther senescence	***	Stage during which the senescence of anther and stamen occurs. Shrinkage of cells and anther structure takes place.
PO:0001040	dry seed stage	***	Mature seed with low moisture content.
PO:0001041	chalazal and micropylar domain establishment	***	The initial stage of endosperm development during which the chalazal and micropilar domains are established.
PO:0001042	functional specialization of the endosperm	***	Stage of endosperm development during which the functional specialization of the maturing endosperm occurs.
PO:0001044	sepal differentiation and expansion stage	***	Stage of calyx development defined by differentiation and expansion of sepal.
PO:0001045	fully expanded sepal	***	Stage of calyx development when sepal is fully expanded.
PO:0001047	lemma developmental stages	***	Stages of development of the lemma defined by characteristic morphological, structural, histological or other visible features.
PO:0001048	palea developmental stages	***	Stages of development of the palea defined by characteristic morphological, structural, histological or other visible features.
PO:0001049	lodicule developmental stages.	***	Stages of development of the lodicule defined by characteristic morphological, structural, histological or other visible features.
PO:0001050	leaf development stages	***	Stages of development of a leaf defined by characteristic morphological, structural, histological or other visible features.
PO:0001051	1 leaf initiation stage	***	The earliest histological evidence of leaf initiation, i.e, a change in the orientation of cell division both in the epidermis and in internal layers of the shoot meristem occurs at this stage (Poethig S, 1997, Plant Cell 9:1077-1087).
PO:0001052	2 leaf expansion stage	***	Stage of leaf development which begins when cell differentiation and cell expansion occurs and finishes when the leaf reaches its full size.n
PO:0001053	3 leaf fully expanded	***	Stage of leaf development when leaf is fully expanded.
PO:0001054	4 leaf senescence stage	***	The final stage of leaf development when the leaf ceases metabolic activity and senesces.
PO:0001055	lemma primordia visible	***	Stage of lemma development that begins when the lemma primordia arise.
PO:0001056	lemma differentiation and expansion stage	***	Stage of lemma development defined by differentiation and expansion of lemma.
PO:0001057	fully expanded lemma	***	Stage of lemma development when lemma is fully expanded.
PO:0001058	palea primordia visible	***	Stage of palea development that begins when the palea primordia arise.
PO:0001059	J bicellular pollen stage	***	Stage of microgametophyte development during which the small generative cell moves inward, becoming completely surrounded by the cytoplasm of the vegetative cell.
PO:0001070	palea differentiation and expansion stage	***	Stage of palea development defined by differentiation and expansion of palea.
PO:0001071	fully expanded palea	***	Stage of palea development when palea is fully expanded.
PO:0001072	lodicule primordia visible	***	Stage of palea development that begins when the palea primordia arise.
PO:0001074	N second mitotic division stage in germinating pollen	***	Stage of microgametophyte development during which the generative cell undergoes a mitotic division to form two male gametes, the sperm cells.
PO:0001077	lodicule differentiation and expansion stage	***	Stage of lodicule development defined by differentiation and expansion of lodicule.
PO:0001078	E expanded cotyledon stage	***	The stage during which embryo axis and cotyledons rapidly elongate as a result of cell division and cell expansion.
PO:0001079	fully expanded lodicule	***	Stage of lodicule development when lodicule is fully expanded.
PO:0001081	F embryo at maturity of a seed	***	Embryo stage at maturity of a seed.
PO:0001083	inflorescence development stages	***	Stages of development of an inflorescence defined by characteristic morphological, structural, histological or other visible features.
PO:0001094	coleoptilar stage	***	The coleoptilar primordium, SAM and radicle are formed in the embryo of grasses.
PO:0001095	true leaf formation	***	During this stage, the protrusion of the first leaf primordia takes place in succession.
PO:0001096	primary endosperm cell stage	***	One cell stage that takes place following the fertilization, produced by the fusion of sperm cell nucleus and one or more polar nuclei.
PO:0001097	A zygote	***	One cell stage that results from fertilization.
PO:0001098	formation of starchy endosperm	***	OBSOLETE. Stage of endosperm development during wich the formation of starchy endosperm occurs.
PO:0001099	formation of aleurone and starchy layers	***	Differentiation of aleurone layer, the outermost endosperm tissue, and the internal starchy tissue.
PO:0001170	seed development stages	***	Stages of seed development, from fertilization to the dry or quiescent state.
PO:0001180	B proembryo stage	***	Early embryo development from two cell stage to a multicellular globular stage before three main tissue systems are differentiated.
PO:0001185	C globular stage	***	During this stage the embryo proper retains radial symmetry (increasing in diameter), and three main tissue systems are established.
PO:0001378	sepals enclosing meristem	***	Stage of calyx development that begins when the developing sepals overlie the floral meristem.
PO:0001380	sepals enclosing floral bud	***	Stage of calyx development that begins when the sepals enclose the floral bud.
PO:0004501	gynoecium differentiation and expansion	***	Stage of gynoecium development defined by differentiation and expansion of carpels.
PO:0004502	closure of carpel(s)	***	Stage at which carpel margins become closely appressed or fused.
PO:0004503	stigma cell differentiation	***	Epidermal cells at the top of developing style differentiate stigmatic papillae.
PO:0004505	fertilized ovule stage	***	The earliest stage of seed development immediately following double fertilization.
PO:0004506	developing seed stage	***	Stage of seed development characterized by seed growth and differentiation.
PO:0004507	D bilateral stage	***	Change from radial to bilateral symmetry takes place during this embryonic stage.
PO:0007021	plant structure development stage	***	The succession of changes during the development of plant parts.
PO:0007501	root cap formation	***	The stage at which the root cap becomes evident.
PO:0007503	A2.1 root intials differntiation of primary roots	***	OBSOLETE. The root initials divide repeatedly and add more cells
PO:0007504	crown root primordium formation	***	The stage at which the initial cells of crown root primordium are formed in  the innermost ground meristem cells by one or two periclinal divisions.
PO:0007505	1 root primordium formation	***	The stage at which root primordium originates and develops at specific locations in embryonic and post embryonic roots.
PO:0007506	primary root primordium formation	***	The stage at which a group of cells or initials that will differentiate into the primary root become organized in the embryo .
PO:0007507	radicle emergence	***	The stage at which the radicle emerges through the coleorhiza.
PO:0007509	root vascular cylinder differentiation	***	The stage at which the root vascular cylinder becomes evident.
PO:0007510	root emergence	***	The stage at which the fully formed root emerges.
PO:0007511	lateral root primordium formation	***	This stage at which the transverse divisions in pericycle cells form the initials of the lateral root primordium.
PO:0007512	A2 root initials differentiation stage	***	OBSOLETE. The root initials differentiate by cell division and cell expansion.
PO:0007513	root cortex differentiation	***	The stage at which the root cortex becomes evident.
PO:0007514	B3 crown root meristem formation	***	OBSOLETE. The stage at which the meristem of the crown root becomes evident.
PO:0007516	root epidermal differentiation	***	The stage at which the root epidermis becomes evident.
PO:0007517	lateral root emergence	***	The stage at which the lateral root emerges.
PO:0007518	crown root emergence	***	The stage at which the crown root emerges.
PO:0007519	5 root hair formation	***	The stage at which the root hairs becomes evident.
PO:0007520	root development stages	***	Stages of development of a root defined by characteristic morphological, structural, histological or other visible features.
PO:0007521	C3.1 metaxylem differentiation of root.	***	OBSOLETE. Differentiation begins with the enlargement and vacuolation of the tracheary elements of the metaxylem.
PO:0007523	establishment of initial cells	***	OBSOLETE. The root initial cells are established.
PO:0007524	B1 primary root meristem formation	***	OBSOLETE. The stage at which the meristem of the primary root becomes evident.
PO:0007525	3 establishment of tissue systems	***	The stage at which distinct tissues become organized.
PO:0007526	F2 root hair elongation	***	OBSOLETE. The stage at which the root hairs are fully elongated.
PO:0007527	2 root meristem formation	***	The stage at which the root meristem becomes evident.
PO:0007528	A2.2 root initials differentiation of lateral roots	***	OBSOLETE. Radial expansion followed by subsequent periclinal divisions forms the pericycle-derived tissues.
PO:0007529	E emerged root elongation	***	OBSOLETE. The stage at which the emerged root starts to elongate.
PO:0007530	A2.3 founder cell derivatives of lateral root	***	OBSOLETE. Radial expansion followed by subsequent periclinal divisions forms the isodiametric founder cell tissues.
PO:0007531	F1 root hair initiation	***	OBSOLETE. The stage at which the roots hairs are initiated.
PO:0007533	C3.3 maturation of protoxylem elements in root.	***	OBSOLETE. The first protoxylem elements next to the pericycle develop secondary walls and mature.
PO:0007534	A2.4 root initials differentiation of crown roots	***	OBSOLETE. Initial cells of crown root primordium divide anticlinally and periclinally to form epidermis-endodermis initial, vascular-cylinder initial and root cap initial.
PO:0007535	A1 root initials formation stage	***	OBSOLETE. After the formation of the apical-basal axis in the young embryo, the central and basal portion give rise to the root meristem.
PO:0007536	root primordium visible	***	OBSOLETE. the root primordium is visbile
PO:0007537	C3.2 maturation of phloem elements in root.	***	OBSOLETE. The first phloem elements matures.
PO:0007539	B2 lateral root meristem formation	***	OBSOLETE. The stage at which the meristem of the lateral root becomes evident.
PO:0007600	3 floral organ development stages	***	Stages of development of floral organs defined by characteristic morphological, structural, histological or other visible features.
PO:0007601	1 floral meristem visible	***	Stage of flower development marked by the emergence of the floral meristem on the flank of the inflorescence meristem.
PO:0007602	2 floral meristem notched	***	Stage of floral development that begins when the floral meristem becomes demarcated from the inflorescence meristem by a slight indentation.
PO:0007603	calyx developmental stages	***	Stages of development of the calyx defined by characteristic morphological, structural, histological or other visible features.
PO:0007604	corolla developmental stages	***	Stages of development of the corolla defined by characteristic morphological, structural, histological or other visible features.
PO:0007605	androecium developmental stages	***	Stages of development of the androecium defined by characteristic morphological, structural, histological or other visible features.
PO:0007606	gynoecium developmental stages	***	Stages of development of the gynoecium defined by characteristic morphological, structural, histological or other visible features.
PO:0007607	sepal primordum visible	***	Stage of calyx development that begins when the sepal primordia arise.
PO:0007608	petal primordum visible	***	Stage of corolla development that begins when the petal or petal-stamen primordia arise.
PO:0007609	sepals 50% of final size	***	OBSOLETE. 50% of the absolute size of the sepals.
PO:0007610	sepals 100% of final size	***	OBSOLETE. 100% of the absolute size of the sepals.
PO:0007611	petal differentiation and expansion stage	***	Stage of corolla development defined by differentiation and expansion of petal.
PO:0007612	fully expanded petal	***	Stage of corolla development when petal is fully expanded.
PO:0007613	stamen primordum visible	***	Stage of androecium development that begins when the stamens or petal-stamen primordia arise.
PO:0007615	flower development stages	***	Stages of development of a flower defined by characteristic morphological, structural, histological or other visible features.
PO:0007616	4 anthesis	***	The phase of a flower when pollen is presented and/or the stigma is receptive.
PO:0007617	5 post anthesis	***	The phase of a flower after the pollen is presented and/or the stigma is receptive.
PO:0007618	carpel primordium visible	***	Stage of gynoecium development that begins when the carpel primordia arise.
PO:0007619	ovule developmental stages	***	Stages of development of the ovule defined by characteristic morphological, structural, histological or other visible features.
PO:0007620	ovule primordium visible	***	Stage of ovule development that begins when the ovule primordia arise.
PO:0007621	megagametophyte developmental stages	***	Stages of development of the megagametophyte.
PO:0007622	integument initiation stage	***	Stage of ovule development that begins when the integument primordia are visible.
PO:0007623	A megaspore mother cell enlarges	***	The stage of megagametophyte development when the megaspore mother cell enlarges.
PO:0007624	B meiosis of MMC	***	The stage of megagametophyte development when the megaspore mother cell undergoes meiosis.
PO:0007625	C tetrad of megaspores	***	The product of meiosis of the megaspore mother cell.
PO:0007626	D megaspore degeneration	***	The stage of megagametophyte development when non-functional megaspores degenerate.
PO:0007627	E two nucleate megagametophyte	***	The stage of megagametophyte development when there are two nuclei.
PO:0007628	F four nucleate megagametophyte	***	The stage of megagametophyte development when there are four nuclei.
PO:0007629	G eight nucleate megagametophyte	***	The stage of megagametophyte development when there are eight nuclei.
PO:0007631	embryo development stages	***	Stages of development of the embryo.
PO:0007632	seed maturation stage	***	Stage during which the seed storage products (storage proteins, lipids and starch) are being accumulated, either in the cotyledons or in the endosperm. Also, LEA proteins are accumulated and subsequentially, desiccation tolerant state is reached at the end of this stage.
PO:0007633	endosperm development stages	***	Stages of development of the endosperm.
PO:0009012	plant growth and development stage	***	The succession of changes leading from the zygote to the mature plant.
PO:0009075	plant ontology	***	OBSOLETE. A controlled vocabulary to describe the various plant parts and the growth and developmental stages.
PO:0021002	calyx absolute size	***	OBSOLETE. The proportion of the absolute size reached by the calyx
PO:0021003	calyx relationship	***	OBSOLETE. The stages of development of the calyx with respect to the rest of the bud
PO:0021004	inflorescence initiation stage	***	Stage of inflorescence development marked by the formation of the inflorescence meristem on a vegetative branch.