Seed identification

 

An in depth knowledge of botany of a plant as well as its seed is necessary, for correct identification of a particular species. In systematic botany or taxonomy the closely related or similar type of plant are grouped into a single category. These groups are: family, genus, species etc. In seed identification the particular seed in question must be identified up to the species level.

 

  The seed, a mature ovule consists of an embryo a protective covering and stored food as endosperm. The identification of seed is usually by comparison, comparing the seeds with a mental image of what something should be, with specimens in a reference collection or with illustration of seeds. In most cases, the useful clues for the identification of seed came from the following characters:

 

1. The size, shape and color of seeds

 

2. The nature, arrangement and pattern of markings that is lines, ridges, pits, projection on the seed surface

 

3. The shape and position of the attachment scar

 

4.  The presence of wings, hair or scale, spines etc

 

5.   The internal structure, position and size of the embryo, presence or absence of the                 endosperm

 

Seed keys are developed on the basis of characters pertaining to family, genus, and species. Once the seed is characterized for a particular family, identification of the seed could easily be made by studying the above mentioned seed characters. Quite  often it is difficult  to identify  the seeds as such. In such situation, growing it to a plant could do identification of seed. The original seed sample of the species is always helpful in identification of unknown unconventional crop and weed seeds.

 

Seed characteristics of some common families

 

1.  Poaceae: seed unit is a caryopsis, a fertile floret a spikelet or a spike. The embryo lies on outside of the endosperm and visible near the base of caryopsis on dorsal side.

 

2.  Leguminoseae: Seeds vary greatly in size, shape and surface characters. The fruit  may be one seeded in several-seeded pod.

 

a)  Mimosoideae'  and  Caesalpinodeae

 

 

i)The  seeds are elongate broad  and flattened, the two  faces being  plane  or

only rounded, colour is varied from black to white and yellow

 

ii)   The hilum  is very small, unspecialized and located at one end of the seed.

 

b)  Papilinoideae

 

i) The  seeds vary  greatly  in  size,  shape, colour  and  location  of  hilum  and

chalaza.

 

ii)   In hilum, there is a fine longitudinal groove or slit down the middle.  The area may be minute, as in some of the clovers, or may be large enough to be seen without magnification as in vetch.

iii)  In  some species the hilum  is obscured by a persisting layer of corky tissue, as in cowpea and beans.

 

3.   Crucifereae: The seeds unit may be a true seed, in indehiscent pod or a segment of a pod.

a) The seeds are mostly spherical, or sometimes slightly flattened

b) The surface has reticulum or netting or lines or ridges

c) The seed surface is covered with microscopic pits. These pits are usually covered with a whitish film, giving the appearance of white spots on the surface.

4. Polygonaceae: The fruit or so called seed is an achene which is three angled or flattened. The outer hull (pericarp) is hard, brown and glossy.

5. Chenopodiaceae: The seeds are flattened, circular or obovate in shape.

 

a) The embryo is either in the form of a ring or horse shoe.

 

6. Caryophyllaceae: The seeds are black or brown, thick and flattened.

b) The surface is roughened by tubercles of various types which are arranged in definite pattern.

 

7.  Euphorbiaceae: Seeds vary greatly in size, shape and surface configuration.

a) The scar is a flattened area at the base. In some species the Scar is obscured by caruncle (whitish corky outgrowth).

b) Distinctive feature of the seed in this family is the presence of prominent raphe.

Solanaceae: The seeds are orbicular, oval or ovate. They are more or less flattened and may be thick or thin.

a) The embryo is curved with an abundant endosperm.

b) The seed surface may be smooth, or variously configure wdith a reticulum, broken lines or pits.

 

9.  Compositeae : The seed unit is an achene which is an indehiscent one, seeded fruit. The top of the achene is usually depressed. In many species there is a fringe of fine bristles or scales around the outer rim.

 

Characteristic of some common seeds

 

Family: Caryophyllaceae

Spergula arvensis: The seed 1-15mm     diameter lens shaped, dull black, thin, flattish with wing. Embryo,      Linear,  ‘U' shaped without endosperm.

 

Family: Chenopodiaceae

 

Chenopodium album (Bathva): The seed is circular,  flat and round; diameter 1-11/2mm, black, smooth     and shiny surface.

 

Chenopodium      murale       (Bathva): Similar to C. album but slightly bigger in size and dull in

appearance.

 

Family: Convolvulaceae

 

Convolvulus arvensis (Field weed): The seed colour, dull grayish brown, length, 4 to        4 1/2mm; surface roughened with fine tubercles or short wavy lines. Back side convex and lateral plane, scar:      inverted 'U' shape and at right angles to the seed’s long axis.

 

Ipomea hederacea: The seed diverse in shape (trigonous wedge, two inner faces are equal): size (lanceolate, ovoid to globose surface; smooth and colour: brown black. Scar: horse shoe shape and usually parallel to long axis.                  1

 

Family: Poaceae

 

Phalaris minor Retz.(Littleseed canarygrass, Canarygrass, Gulli danda): Seeds hard, with palet covering the grain,      which is oval with an acute angle at one end and about      3-5mm       long. Glossy and brownish grey in colour.

 

Avena        fatua (Wild oat): The seed consists of mature floret,       narrowly cylindrical, tapering at apex, bears a twisted and bent dorsal awn,    ventral       side flat with fine grooves; colour: grey, brown or black, yellow   to white.

 

Panicum spp: The seed unit consists of one seeded spikelet. The grain surrounded      by glumes (thin and  papery). Lemma and Palea (hard, smooth and shiny, size: 1 1/2 to 2 3/4 mm usually lance shape.

Setaria      etalica:      The seed unit    consists of one seeded spiklet. The grain surrounded by glumes (thin, papery and smooth). Lemma and Palea (hard, smooth      and shiny)

Family: Liliaceae

Asphodelus tennuifolius (wild onion): The seed 1 1/4 long, flattened eleptical three angled. (sharp) acute and black (crustraceous) testa.

 

 

 

Family: Papaeraceae

 

Argemone mexicana L (Maxican poppy, Satyanashi ): Seeds nearly 2 mm long, ovoid, spherical surface with angular depression and a crest along one side, blackish brown in colour

 

Fumaria parviflora: Fruit very small, globose, one seeded, indehicent nutlet, rugose when dry and rounded at the top with two pits, color usually green.

 

Family: Papillionaceae

Medicago sativa (Lucerne): The seed roughly oval (scra lies in board indetiation near one end or kindly shape twisted the congaxes (scar lies in middle of a didtinct notch). Colour greenish yellow or light brown, length 1½ mm and width 2½ mm to 3mm.

 

Melilotus alba (white sweet clover): The seed is identified by size (bigger length about    2 ½ mm and width 1½ mm), shape oblong to oval and translucent in apperence), and colour. (golden yellow to light brown). Scar lies in shallow indentiation near top.

 

Family:  Polygonaceae

 

Rumex sp (wild spinach): Seed three sided acute as both ends, brown, spinning segments if present with long, fine teeth on the margins.

 

Family: Compositae

 

Helianthus spp (Wild Sunflower): Seeds are, long in size, trigonous, very small hairs present on seed surface and dark brown to black in colour.

 

Cichorium intybus (Coffee chicory, Large rooted chicory, Chicory): Seeds are up to 3mm       

Long, trigonous wedge shaped, pale brown to gray and white in colour, pappus of scales present.

 Carthamus oxycantha(Wild  safflower): Seeds are smaller than that of cultivated safflower, elongated in shape, grayish in colour with variegation/mottling on seed coat.

 

Crop

                              Name Of The Weed

 

Common

English

Scientific

Paddy

 

Wild rice

Oryza sativa L.Var.Fatua
Prain(Syn.O.sativa L.F
spontanea Rosch)

Wheat,triticale

HiranKhuri
Gulli danda

Wild Morning Glory

Convolvulus arvensis L.
Phalaris minor Retz

Mustard,Taramira

Sattyanashi

Mexican prickly poppy

Argemone mexicana L.

Safflower

 

Wild Safflower

Carthamus oxycantha M.Bieb

Sunflower

 

Wild sunflower

Helianthus spp.

Barseem

Kasmi

Chicory

Chicorium intybus L.

Lucerene

 

Dodder

Cuscuta spp.

Napier grass

 

Canada thistle

Cirsium arvense L.scop

 

 

Dodder

Cuscutta spp.

 

Baru

Johnson grass

sorghum halpense L.pers

 

 

Quack grass

Agropyron repens
L.P.Beauv

 

HiranKhuri

Wild morning glory

Convulvulus arvensis L.

Oat

 

Wild Oat

Avena fatua L.

Bitter gourd

Mocha
Kakrol,Bhat
Kakrol
Jangli Karela

Balsam apple

Momordica balsimine
M.cochinchinesis spreng

Cucumber,

 

 

Cucumis hardwickii Royle
 

Long melon

 

 

Cucumis prophetarum

Musk melon

Takmek

Weed melon

Cucumis melo(L.) var.
argestis Nand

Snap melon

 

Non desert form of
Cucumis melo(L.)

 

Snake ground

 

 

Trichosanthes palmate L.
T. lobata L.

 

Rambel

Janghi chachinda

T. cucumerina L.

 

Indrayan

Wild Water melon

Citrullus colocynthus L.

 

 

Wild okra

A. ficulenus L. wt & Arn.

 

 

Wild okra

A. manihor L. Medic. & Arn.

 

 

Wild okra

A.moschata L.
Medic & Arn.

Amarnath

Kantewali
chaulai

Wild amaranth

Amaranthus spinosus L.

Fenugreek

Methi

 

Trigonella corniculata L.

 

Senji

 

Melilotus alba

Lettuce

 

Wild letuce

Lactuca sativa L.

 

 

 

Lactuca scariola L.