Variation of Calcium Oxalate (CaOx) Crystals in Porang (<i>Amorphophallus muelleri Blume</i>)

doi:10.4236/ajps.2013.49217

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American Journal of Plant Sciences, 2013, 4, 1765-1773

http://dx.doi.org/10.4236/ajps.2013.49217 Published Online September 2013 (http://www.scirp.org/journal/ajps)

Variation of Calcium Oxalate (CaOx) Crystals in Porang

(Amorphophallus muelleri Blume)

Nurul Chairiyah*, Nunung Harijati, Retno Mastuti

Biology Department, Faculty of Mathematic and Natural Sciences, Brawijaya University, Malang, Indonesia.

Email: *[email protected]

Received June 25th, 2013; revised July 25th, 2013; accepted August 15th, 2013

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

This research had aimed to determine variations in form of calcium oxalate (CaOx) crystals in porang. Slides for mi-

croscopic observation were prepared from sliced leaf, petiole, and tuber of porang. Sliced organs were cleared by using

modified clearing method. The parameters that were observed included form and variety of morphology type of CaOx

crystals. Microscopic observation showed there were four basic forms of crystals, i.e., druse, raphide, prism and styloid

with some variation of diverse types, each of which had 49, 10, 8, and 5 variations. CaOx crystals, based on the size,

were grouped into large (20 - 250 µm) and small (1 - 15 µm) crystals.

Keywords: Porang; Variation; Shape; CaOx Crystals

1. Introduction

Calcium oxalate (CaOx) crystals can be found in all pho-

tosynthetic organisms including algae. The production of

CaOx crystal in plants is a normal physiological process

and as a potential defense mechanism. These crystals can

be found in the vegetative, reproductive, storage, and de-

veloping organs, and also in photosynthetic and non-pho-

tosynthetic tissues [1,2].

CaOx crystals are formed from calcium (Ca) that de-

rived from the environment and oxalic acid (2-carbon di-

carboxylic acid). CaOx crystals’ formation through sev-

eral metabolic processes from different biochemical path-

ways, i.e. glyoxylate and ascorbic acid pathways [3]. Ac-

cording to Franceschi and Nakata [2], crystal formation

required coordination of several different mechanisms.

These mechanisms include expense of Ca from the apop-

last. Ca transfer from the cytosol into the vacuole, and

then it was transferred into the crystal chamber. Silmu-

taneously, the oxalic acid was synthesized in the cyto-

plasm and transferred to the vacuole and the chamber.

CaOx crystal forms which were often found in plants

were raphide (needle-shaped), prism, druse, styloid and

sand crystals [1,2]. Prism crystal shaped like a rhombo-

hedral box, which was generally found in the single form

crystals per cell or more. Raphide crystal was a rectan-

gular styloid crystal which had been thickened and leng-

thened. It could be found in the form of single crystal or

bundle crystal per cell in plant. Sand crystal was derived

from an association of a small angular crystal. Druse

crystals were derived from the combination of multifacet

crystals. Druse crystal could consist of one or more per

cell [2]. Styloid or pseudo-raphide crystal had a shape

thicker than common raphide crystal and is usually soli-

tary in the cells [4]. CaOx crystals which were found in

the cell walls were generally rhombohedral or prismatic

crystals, whereas crystals in the cells could be raphide,

druse, and sands crystals [2].

Each form of CaOx crystals has varieties of morpho-

logical crystal types. This statement was supported by the

researches of Keating [5], Cote [6], and Crowther [7] by

using Araceae Family. They stated that raphide and druse

crystals had varieties of morphology types, such as sim-

ple raphide, elongated raphide, druse, very small druse,

biforine, and varieties of ends raphide crystals. Varia-

tions in the type of crystal morphology could be found

throughout the plant organs.

Porang (Amorphophallus muelleri Blume) is a bulbous

plant, which is native to tropical areas. Porang can cause

irritation and itchy when it consumed because it contains

calcium oxalate crystals [8]. Based on the results of re-

search conducted by Prychid et al. [9], plant of the genus

Amorphophallus, which was a member of Family Araceae,

accumulated CaOx crystals, generally in raphide and

druse crystal form. However, it was possible to find other

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume)

1766

crystal types in Amorphophallus because some species

which were grouped in Family Araceae could accumulate

other crystal types in their tissue [1,6,10-14]. Therefore,

it was interesting to observe the possibility of a variety of

shapes and types of CaOx crystals in porang (Amorpho-

phallus muelleri Blume). In different organs thought to

have a variation of different forms of CaOx crystals, ob-

servations of a number of variations type of CaOx crys-

tals in the porang leaves, petiole, and tuber were appar-

ently valuable.

2. Materials and Methods

2.1. Preparation Microscopy Material

Leaf, petiole and tuber of Porang were used as micros-

copy material. The materials were harvested from eight

weeks old of Porang

2.2. Preparation of Microscopy Slide

Preparation of microscopy slide from leaves sample were

conducted by cutting 1 × 1 cm2 at three locations per

intact leave using razor blade. Different with leaves, pe-

tiole samples were obtained from skin and central part of

petiole. Petiole sampling included top-, middle- and

base-part of petiole, whereas tuber sampling taken from

the edge and center of the tuber. Sample slices of petiole

and tuber were prepared using hand clamp sliding micro-

tome.

The cut and sliced sample was cleared according to

Ilarslan et al. [15] with some modification as followed:

all samples were soaked in 5% NaOH at 37˚C for 24

hours. After incubation, the sample transferred to 50%

sodium hypoclorite commercial at room temperature for

1 hour. Rinse in running tap water was required after

soaked in sodium hypoclorite and followed by dehydra-

tion in alcohol series 30%, 50%, 70%, 80% for 10 minute

to each sample. The last step of dehydration was con-

ducted in 100% EtOH for 5 minutes. The cut or sliced

object were place on slide glass, mounted with Hoyer so-

lution and covered using cover glass. Now all slide ready

to observe under light microscope (Olymphus CX31) at

100, 400, and 1000 times magnification. The observed

objects were documented using a digital camera 7.2 MP.

3. Results and Discussion

3.1. The Forms and Types of Caox Crystals in

Leaf, Petiole, and Tuber of Porang

(Amorphophallus muelleri Blume)

In general we found four basic forms of CaOx crystals in

Porang (A. muelleri). They were 1) druse (large and small

size), 2) raphide (bundle and single), 3) prism, and 4) sty-

loid crystals. These results were different with Prychid et

al. [9] which stated Amorphophallus plants only accu-

mulated raphide and druse crystals. However, Cote [6]

found three basic forms of CaOx crystal in Dieffenbachia

seguine, species that have same family with A.muelleri,

Araceae family. The crystals included druses, rhapides,

and prisms. In detail the CaOx crystals that we found as

below.

3.2. Druse Crystal

Druse crystals had a variety of sizes, types, globular forms

and its constituent units. Such crystals were grouped into

two categories, namely small druse which had 5 - 13 μm

in diameter and large druse with 20 - 135 μm in diameter

(Figure 1). Based on druse diversity type, we found four

types, i.e. solid druse, semisolid druse, and loose druse

(Table 1).

The classification three types of druse crystal were

based on differences in the composition of globular crys-

tal that made up those crystals. We found druse crystal

which had morphology thick ring in the edge and empty

in center under observation at 100× magnification. How-

ever, when we altered focus by move up and down of

microscope knob, we found center part actually not abso-

Figure 1. The difference between large and small CaOx

crystals in Porang (red circle): Inset shows the difference

between large and small druse crystal in leaf.

Table 1. Crystal druse types in porang (A. muelleri).

Type Diameter

(µm) Globular Forms Constituent

Unit

Solid Druse Densely Like Rose

Petals

Semisolid

Druse Only on the Edges Like Rose

Petals

Loosely

Druse

20 - 135

There Is a

Distance/Tenuous

Like Glass

Flakes

Prism

Stiloid

Small Druse5 - 13 Densely

Prism and

Stiloid

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume)

1767

which were found in petiole were solid druse, semisolid

druse, and loose druse. Small druses were not found in

this organ. Just the same as druse crystals which were

found in the leaves, druse crystals which were found in

petiole were located very close. The close form was two

or three crystals coincide, or stuck together.

lutely empty, it had very thin structure. We named semi-

solid for such entire feature (Figure 2(d)). We called

solid when in the center of crystal full with constituent of

crystal and observation in detail showed that look like

roses. The entire morphology of that crystal formed a

perfect sphere and no concave on its structure (Figure

2(c)). The loose type was given to druse crystal which

had less perfect of globular structure, in between consti-

tuen unit had tiny distance (Figure 2(e)). Distribution of

big size crystal include leaves which had size 20 - 60 μm,

petiol and tuber with size 20 - 40 μm and 30 - 135 μm re-

spectively. Apparently those variation sizes were caused

by genetic variation.

Druse crystal types which were found in tuber i.e.

semisolid and loose druse crystals. As in the leaf and pe-

tiole, druse crystals were also found in pairs but not as

much as in the leaf. And the crystals, especially the solid

one had darker color than it found in the leaf. Generally

druse crystals had form like roses. However, druse crys-

tal in tuber had forms like a solid lump of noodles if ob-

served under microscope with low magnification (Figure

2(g)). However, if it observed under the highest magni-

fication, the forms of lump noodles were compact rather

than scarce. The group of lump noodle form consisted of

2 - 5 druse crystals that were closely (Figure 2(h)).

Noodless group crystals had a diameter 80 - 135 μm in

size. Some varies types of druse crystal that we found in

line with Prychid et al. [9] statements. They mentioned,

druse crystals were found in all of Amorphophallus spe-

cies have variation of crystal number and size, ranging

from one or several small crystals. Each druse was a

group of various forms of inter-crystalline closed toge-

ther each other.

Small druse crystals had diameter between 5 - 13 μm,

only could be observed under microscope with 1000 ×

magnification. These small druse crystals were grouped

into three types based on the composition of crystals con-

stituent. Small druse crystals were composed of styloid

crystals only (Figure 2(b)), prism crystals only (Figure

2(a)), and mixed prism and styloid crystals. These small

druse crystals had a transparent white color.

In leaf, druse crystals commonly were found in the

adaxial site, which was the most frequently exposed to

sunlight (Figure 1). Solid druse crystals were abundant

in the leaf. Solid druse crystals generally were found in

pairs with another solid druse crystal. Semisolid (Figure

2(d)) and loose (Figure 2(e)) druse crystals were rarely

found in leaf. Small druse crystals that were found in leaf

had several different forms, namely small druse crystals

were composed of styloid crystals only (Figure 2(b)),

prism crystals only (Figure 2(a)), and combination of

prism and styloid crystals.

3.3. Raphide Crystal

In addition to having variations in size and type, raphide

crystals that were found in porang also had color variation

(Table 2). Raphide crystals were found in the form of a

single and bundle crystal. The size of crystal length grouped

into long and short size. The long one had ranged from

In petiole, druse crystals were found align vertically

and sometimes in pair form. The types of druse crystal

(h)

(g)(f)

(b) (a)

(e)

Figure 2. Variation of druse crystal types in Porang: (a) Small druse crystal was composed of prism crystals; (b) Small druse

crystal were composed of styloid crystals; (c) Solid druse crystal; (d) Semisolid druse crystal; (e) Loose druse crystal; (f) Solid

druse crystals that coincide; (g) Noodles solid druse crystals; (h) Noodles druse crystal was composed of five solid druse crys-

tals.

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume)

1768

135 - 250 μm in length and 37 - 80 μm in length for short

size. The classification was based on differences in shape,

color, size, neatness of crystal edge, whole crystaline or-

ganization.

Bundle straight edge raphide crystals which had size

37 - 65 μm in length was composed of a group of needle

shape raphide crystals, well-organized and had straight

edge. Bundle raphide which had size 37 - 65 μm in

length could be classified into short raphide crystals. This

was because the length of the single raphide crystals that

made up the bundles tends to be shorter than the long one.

Not straight edges short raphide crystal was composed of

a group of short raphide crystal, well-organized but

didn’t have straight edge. Not neatly organized short

raphide crystal was composed of a group of short raphide

crystals and the arrangement of the crystals was not ir-

regular but still organized. Not organized short raphide

crystal was composed of a group of unorganized short

raphide crystals and it was not irregular but still formed a

group. Organized bundle short raphide crystal and each

Table 2. Types of crystals raphide in porang (A. muelleri).

Whole Crystalline Organization

Type Colour Size (µm) Neatness of Crystal Edges

Organized neatness

Additional Information

straight Oa N

c -

Not straight Oa N

c -

Not straight Oa nNd -

Not straight Oa nNd Puncture each other

135 - 250

Not straight nOb nNd -

straight Oa N

c -

Not straight Oa N

c -

Not straight Oa nNd -

Not straight Oa nNd Puncture each other

Black

37 - 80

Not straight nOb nNd -

straight Oa N

c -

Not straight Oa N

c -

Not straight Oa nNd -

Not straight Oa nNd Puncture each other

Brown 37 - 80

Not straight nOb nNd -

straight Oa N

c -

Not straight Oa N

c -

Not straight Oa nNd -

Not straight Oa nNd Puncture each other

Dark Brown 37 - 80

Not straight nOb nNd -

Reddish Brown 37 - 80 Not straight Oa nNd -

straight Oa N

c -

Yellow 37 - 80

Not straight Oa N

c -

Bundle

Slightly Greenish Yellow37 - 80 Not straight Oa N

c -

135 - 210 -* nOb -

* -*

Single Transparent

37 - 80 -* nOb -

* -*

Can not be observed clearly; aOrganized; bNot organized; cNeat; dNot neat.

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume) 1769

puncture was composed of two or more short raphide

crystals that were laid very close so that groups were in-

tersected (stabbed each other) (Figures 3(h) and (j)). In

addition to bundle form, raphide also had single form.

The crystal which had 37 - 80 μm in size was single short

raphide crystal which was not form a group and it was

spreading. Generally single raphide crystal which had 37

- 80 μm in size based on the observation was not con-

tained in idioblast cell.

By focus on individual crystal, we found three types of

crystal end morphology. They include pointed end (Fig-

ure 3(f)), blunt end, and hook end (Figure 3(g)).

Raphide crystals that were found in porang had several

different colors. The crystals colors were grouped into

dark and bright colors. Crystal colors which were grouped

into dark colors i.e. dark brown (Figures 3(h) and (i)),

reddish brown and black colors. Crystal colors which

were grouped into bright colors i.e. transparent white,

yellow (Figure 3(k)), greenish yellow (Figure 3(l)), and

brown (Figures 3(j) and (n)) colors. Long black and

short black raphide crystal in the bundle-shaped had

black color. Single long and short raphide crystal had a

transparent white color. Short brown raphide crystal had

several colors i.e. greenish yellow, yellow, and light

brown colors. Short dark brown raphide crystal also had

two colors i.e. deep brown and reddish brown colors.

Raphide crystal formation on porang occurs in the

early stages of leaf development of organs and tissue dif-

ferentiation. Generally raphide idioblast was gradually

formed and organized, and initiated the formation raph-

ide continuously throughout life of plant tissues. Raphide

crystals in Amorphophallus could as defend weapon to

attacks from herbivorous animals, and contribute to the

accumulation of Ca and reabsorption under certain envi-

(m) (n) (o)

(d)

(g)

(b)

(a)

(h)

(f)

(e)

(l)

(k)

(i) (j)

(c)

(p)

Figure 3. Variation of raphide crystal types in porang: (a) Straight edge long black raphide crystal; (b) Not Stright edge long

black raphide crystal; (c) Not neatly organized long black raphide crystal; (d) Long black raphide crystal with puncture each

other structure; (e) Not organized long black raphide crystal; (f) Single raphide crystal with pattern central line and pointed

end; (g) Single raphide crystal with pattern central line and hooked end; (h) Short dark brown raphide crystal with puncture

each other structure (formed a fold); (i) Short perfect block shaped dark brown raphide crystals; (j) Short brown raphide

crystals with puncture each other structure (formed a belt pattern (arrow)); (k) Not straight edge short yellow raphide crys-

tals; (l) Straight edge short slightly greenish yellow raphide crystal; (m) Spherical Shape of short bundle raphide crystal; (n)

Short imperfect block shaped brown raphide crystal; (o) Sequenced of five short bundle raphide crystals; (p) Brittle raphide

rystal. c

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume)

1770

ronmental conditions, while the druse crystals only play a

role in the buildup process for the exiled (sequestration)

[2]. Raphide crystals had a variety of sizes and number,

per bundle 100 to 800 single raphide crystal. Single rap-

hide crystals had a constant thickness in the middle and

tapered at the edges. Each crystal had two opposing

grooves, cavities in almost all parts of the crystal that

comes from the center of the crystal. Latch or hook at the

end of raphide crystals could be found in some of Amor-

phophallus species [9], one of them was Porang (Amor-

phophallus muelleri).

Raphide crystals that were found in leaf were grouped

into bundle and single form. The bundle had two size,

namely short (around 75 - 80 μm in size) and long (135 -

250 µm in size). And the single had size 37 - 80 µm. In

the leaf, we found unique form i.e. sequenced five short

crystals (Figure 3(o)). The color of raphide crystals in

petiole was generally black, dark brown, reddish brown,

brown, and transparent.

Raphide crystals that were found in petiole had some

similarity form with leaf’s crystals. Some crystals seemed

broken so that the crystal looks rough, brittle, and frizzy

(Figure 3(p)). The color of crystal included black, dark

brown, brown, and transparent. Such as in leaves, petiole

also had varied form and size of crystal. The bundle ra-

phide was categorized short and long. Example short size

was in Figure 3(j). The crystal had pretty morphology,

i.e. flag shape with brown color.

Raphide crystals in tuber were dominated by short-

bundle form and both black and brown colors. The bun-

dle had conspicuous morphology, block and spherical

shape. The block shape was divided into two types,

namely perfectly block-shaped (Figure 3(i)) and imper-

fectly block-shaped (Figure 3(n)). The spherical shape

could not divide into certain category because they didn’t

have various shapes. Example of spherical shape was like

“compresed rugby ball” (Figure 3(m)). Raphide crystal

had some varies color. They were black, dark brown,

reddish brown, brown, yellow, slightly greenish yellow

and transparent colors. Single raphide crystal in tuber had

patterns that were not much different from that were

found in leaf and petiole. Although rarely found in tuber,

it was recognised single raphide crystals which has a

curved shape.

Variations of raphide crystals that were found in this

study presumably were caused by genetic influences.

Franceschi and Nakata [2] explained that the crystal size

variation within a species was influenced by intrinsic fac-

tors (genetic factors). In addition to genetic factor, envi-

ronmental factors also influenced crystal formation. The

availability of calcium was example of environmental

factor.

3.4. Prism Crystal

Prism crystals which were found in porang were trans-

parent white, rectangular shape and composed of six as

well as single (Figure 4(a)) or in groups (Figures 4(b)-

(d) and (f)) with size 2 - 20 μm (Table 3). It was also

found that short agglomeration that had 2 - 10 μm in size.

Based on observation, prism crystals that were found

in leaf were divided into groups and single prism crystal.

it could be composed of single prism crystal with the

same shape (Figure 4(b)) or different, like a prism crystal

group which was composed of single prism crystal 11 -

20 μm in size and single prism 2 - 10 μm in size (Figure

4(c)). Single prism crystals that were found in leaf, i.e.

single prism which had 2 - 10 μm in size (Figure 4(a)),

(f)

(e)

(d)

(c)

(b)

(a)

Figure 4. Variation of prism crystal types in porang: (a) single prism crystal with size about 2 - 10 μm; (b) Prism crystal

group that were composed of single crystal with size about 2 - 10 μm; (c) Prism crystal group that were composed of single

crystal with size about 2 - 10 μm and single prisms crystal with size about 11 - 20 μm; (d) Prism crystal group that were

composed of single prism crystal with size about 11 - 20 μm; (e) Hexagon prism crystal; (f) Prism crystal group that were

omposed of two hexagon crystals. c

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume) 1771

single prism which had 11 - 20 μm in size, and hexagon

prism crystal (Figures 4(e) and (f)).

Prism crystals that were found in petiole were divided

into single and group of crystal. Single prism crystals

that were found in petiole had several different forms,

such as single prism crystal which had size 11 - 20 μm

and 2 - 10 μm. Prism crystal group that were found in

petiole also had several different forms, such as a prism

crystal group which was composed of size 2 - 10 μm

prism crystals, a prism crystal group which was com-

posed of hexagon prism crystals, and prism crystal groups

which was a combination of hexagon prism crystals and

size 2 - 10 μm prism crystal.

Prism crystals that were found in tuber had similar

variation with the one in petiole and leaf. Therefore it

was divided into 3 types of prism crystals, i.e. single

prism crystal which had 11 - 20 μm in size, slim single

prism crystal, and single prism crystal which had 2 - 10

μm in size. Prism crystal group that were found could be

composed of single prism crystal with a particular form.

The form of prism crystal groups were composed of a

slim single prism crystals which had 11 - 20 μm in size

and slim single prism crystals which had 2 - 10 μm in

size.

Prism crystal that had found in porang had different

size with the one in another species from Family Araceae.

Some of species from Family Araceae had longer size of

prism crystal, e.g. prism crystal in Dieffenbachia seguine

had size of about 48 μm and about 65 μm in Caladium

bicolor and Xanthosoma sp. Prism crystal in Dieffenba-

chia seguine, Caladium bicolor and Xanthoso ma sp

could found in inside the thecae, mixed in with the pollen

grains [14].

There was also a group called agglomeration prism

crystal (Figures 5(e) and (f)) [16]. Named agglomeration

prism crystal based on irregular crystalline forms. These

crystals were one of the types of crystals that could be

found in all plant organs has been observed. Although it

could be found throughout of the plant organs, these

crystals were present in small amounts. It could be found

in a single or a group of crystal. Agglomeration prism

crystal had a translucent white color.

3.5. Styloid Crystal

Styloid crystals that contained in porang were transparent

white which had a size range of 2 - 13 μm and composed

of single or group (Table 4). Styloid crystals which were

arranged regularly and lined up neatly were generally

found in groups. Otherwise, single styloids that were

spread were grouped in an irregular arrangement. Styloid

crystals that were found in leaf usually present in group.

Styloid crystal groups could be found in the form of

Table 3. Types of crystal prisms in porang (A. muelleri).

Type Size (µm) Angles/ Side

11 - 20 Four

2 - 10 Four

Single

11 - 20 Six

11 - 20 Four

2 - 10 Four

2 - 10 Six

Group

2 - 20 -*

Agglomeration 2 - 10 -*

*Could not be observed clearly

(c)(a)

(e) (f)

(b)

(d)

Figure 5. Other Variation of small crystal types in porang: (a) Regular styloid crystal group with size about 2 - 10 µm; (b)

Styloid crystal group that were composed of styloid with size about 11 - 13 µm and the smaller one (2 - 10 µm); (c) Irregular

styloid crystal group with size about 11 - 13 µm; (d) Irregular styloid crystal group with size about 2 - 10 µm; (e) Agglomera-

ion prism crystal group; (f) Single agglomeration prism crystal. t

Variation of Calcium Oxalate (CaOx) Crystals in Porang (Amorphophallus muelleri Blume)

1772

Table 4. Types of crystals in porang stiloid (A. muelleri).

Type Size (µm) Position

2 - 10 Irregular

Single

11 - 13 Irregular

Regular

2 - 10

Irregular Group

11 - 13 Irregular

regular (lined up neatly) (Figure 5(a)) and irregular

(Figures 5(b)-(d)). Styloid crystal group might be com-

posed of crystals that had 2 - 10 μm in size only, styloid

crystals 11 - 13 μm in size only, and the combination of

both. Styloid crystals were dispersed irregularly in leaf.

As the one that had found in leaf, styloid crystals that had

found in petiole were also divided into single and group

crystal. Generally styloid crystals that were found in tu-

ber always spread and irregular. In tuber, styloid crystals

were found in single and group crystal. There was also

transparent styloid crystal that was arranged puncture

each other in tuber. Grouping styloid crystals could be

seen in Table 4.

CaOx crystal types that were found in each porang or-

gan were varies. Level of diversity of CaOx crystals that

were found was different in each porang organ (Table 5).

The highest diversity of druse and raphide crystals was

found in tubers, i.e. 80% and 91.84%. Different with

druse and raphide, the highest prism crystals diversity

was found in petiole (100%). However diversity of sty-

loid crystal was equal between leaf and tuber, i.e. 80%.

From the results of these calculations, it could be con-

cluded that each organ in porang had different types of

CaOx crystals morphology.

Differences in level of diversity of each CaOx crystal

types in each organ were allegedly due to the environ-

mental factors and genetic regulation that express the di-

versity of crystal types in each porang organ. In addition,

variations of crystal type that were found in porang had

some differences with CaOx crystals that were found in

other Araceae species. Therefore there were allegations

that the variations of crystal type that were found in this

research were a hallmark of these porang. As explained

by Ilarslan et al. [13] and Franceschi and Nakata [2],

morphology and distribution of CaOx crystals within a

species is influenced by genetic control. Also explained

by Franceschi and Nakata [2], determination CaOx crystal

types and distribution could be classified as a taxonomic

character for species classification.

4. Conclusion

Tuber organ has the highest diversity of crystals com-

pared with other organs, with the percentage of 91.84%

Table 5. Variability types caox crystals in leaf, petiole, and

tuber in porang (A. muelleri).

Porang organs

NoType of CaOx Crystals

Leaf (%) Petiole (%) Tuber (%)

1Rafida (na) = 49) 59.18 61.22 91.84

2Druse (na) = 10) 60 70 80

3Prisma (na) = 8) 87.50 100 87.50

4Stiloid (na) = 5) 80 60 80

aWhole number variation morphology of CaOx crystal, which n = 100%.

for rafida, 80% for the Druse, 87.50% for the prism, and

80% for stiloid. In all three organs (leaves, leaf stalks,

tubers) of porang plants (A. muelleri), four basic shapes

of crystals, namely 1) druse, 2) raphide, 3) prism and 4)

styloid crystals were obtained. From observations of crys-

tal morphology, raphide crystal variation types of crys-

tal had the highest compared with other crystals. CaOx

crystals were divided by size into large crystals (20 - 250

μm) and small crystal size (1 - 15 μm).

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