Biometric Characterization of Fruits and Morphoanatomy of the Mesocarp of Acrocomia Species ( Arecaceae )

The genus Acrocomia (Arecaceae) is widely distributed in the Neotropics, without consensus on the number of species. The arboreal species are explored in their native countries. To subsidize better use of the observed variation in fruits of different species for product extraction, taxonomy, conservation and genetic improvement, our objective was to characterize biometrically the fruits and anatomically the mesocarp from natural populations of A. aculeata, A. intumescens and A. totai. We observed different colors of epicarp and mesocarp in A. aculeata and A. totai, while the fruits of A. intumescens were light green or yellowish. The fruits of A. aculeata showed diameter considered large (3.9-4.6 cm) and the highest dry mass (26.3-33.5 g), A. intumescens presented intermediate diameter (3.1–3.9 cm) and mass (11.5-18.8 g), and A. totai had the smallest diameter (2.2-3.0 cm) and mass (4.1-11.4 g). The morphoanatomical analysis of the mesocarp did not distinguish the three species. However, it revealed the presence of useful compounds for human consumption and with economic potential, such as oil in the parenchyma cells, mucilage, starch and phenolic compounds. We concluded that the mesocarp anatomy is not useful for taxonomy, but the biometric variation is, as well as variation within species can be applicable in conservation and genetic improvement.


Introduction
The genus Acrocomia is Neotropical and the number of species is not yet well taxonomically well resolved.According to Henderson et al. (1995), only two species are attributed to the genus: A. aculeata (Jacq.)Lodd.ex Mart.and A. hassleri (Barb.Rodr.)W.J. Hahn, the first having large size, widely distributed along Central and South Americas, and the second, small, restrict to some areas of Cerrado of Brazil and part of Paraguay.Lorenzi et al. (2010) recognize seven species in the genus, six occurring in Brazil: A. aculeata, A. intumescens Drude and A. totai Mart., of arboreal size, and A. hassleri, A. glaucescens Lorenzi and A. emensis (Toledo) Lorenzi, of small size; and A. crispa (Kunth) C.F. Baker ex Becc., of arboreal size, endemic to Cuba.Furthermore, according to The Plant List (2013), all previously cited species are considered valid plus A. media O.F. Cook., endemic to Porto Rico and Virgin Isles, also of arboreal size, but Proctor (2005) mentions it as a lower plant, with larger leaves and smaller spathe compared to A. aculeata.
The species of Acrocomia are utilized for several purposes.The palms are utilized as ornamental species in different countries of occurrence (Lima, 1994;Moraes, 2004;Silva, 2012).In Mexico, Bolivia and Brazil the roots are utilized as medicine (Amorozo & Gély, 1988;Hernández et al., 2011;Moraes, 2004).In countries of Central America, Mexico, Venezuela and Brazil it is common the utilization of sap of the stipe to prepare an alcoholic drink (Balick, 1984;Bran, 2013;Corrêa, 1984;Hernández et al., 2011;Lentz, 1990;Plotkin & Balick, 1984).The leaves are utilized for rooves or as raw material to obtain fibers for production of lines, ropes and nets, and as good quality forage (Moraes, 2004;Pott, 1986).
Although all parts are utilized, the fruits have the highest diversity of economic exploration, being utilized for human fresh or processed food, presenting good nutritional quality and medicinal purposes (Hernández et al., 2011;Ramos et al., 2008).Nevertheless, the highest interest in exploration of the fruits is for their potential for production of oil of the mesocarp (pulp) for biofuel, over 4,000 Kg/ha/yr, and of the nut oil for cosmetics.
Among the recognized species, in Brazil, three are explored for extractivism for presenting fruits of commercial interest: A. aculeata, popularly known as macaúba, with occurrence in various states of Brazil; A. intumescens, locally called macaíba, endemic to the Northeast region, occurring in areas of the called Zona da Mata (forest zone)and in altitude forests; and A. totai, known as bocaiúva, distributed in most part of the state of Mato Grosso do Sul, associated to areas de Cerrado and Pantanal (Lorenzi et al., 2010;The Plant List, 2013).
The three species can be morphologically distinguished, mainly by the characteristics of the stipe: A. aculeata has very spinescent stipe and presence of the rests of leaf sheath; A. totai presents lower number of spines and sporadically the rests of the leaf sheath; and A. intumescens has spines only when young, presenting swelling in the middle of the stipe and without rests of the leaf sheath (Lorenzi et al., 2010).
The fruit is of the drupe type, derived from superior ovary, characterized by the presence of stony epicarp (peel), fleshy mesocarp (pulp) and stony endocarp (Esau, 1977).The fruits of the species of Acrocomia are globose, present hard epicarp, strongly adhered to the mesocarp when young, and generally brittle, easily detaching from the mesocarp when ripe.The mesocarp is mucilaginous, with large quantity of fibers.The endocarp is woody and thick (Dransfield et al., 2008;Lorenzi et al., 2010).
The three studied species are explored for consumption or commercially.The fruits of A. intumescens in the Northeast region and the fruits of A. totai in the state of Mato Grosso do Sul are explored by local communities for consumption of pulp and fresh or processed nut in several types of foods, such as meal, ice cream, cake and others.Some of the products are sold by these communities as source or complement of family income.The species A. aculeata has been explored, mainly in the state of Minas Gerais, for extraction of oil of pulp and nut for production of biofuel and cosmetics.Historically, the oil of A. aculeata was used for street lightning of important old mining towns, such as Ouro Preto and Mariana, Minas Gerais.
Considering that the economic potential of the species of Acrocomia is based, mainly, in the exploration of its fruits, studies on biometric characterization of fruits of different species from different regions are of great importance.The biometric characterization of fruits is fundamental to subsidize conservation and exploration of plant resources, since such data allow to estimate the productivity and to sort more homogeneous seed lots and, consequently, with more uniformity and vigor (Moura et al., 2010).It is also a useful tool for detection of genetic variability within populations of a same species and the relations between this variability and environmental factors, information useful in genetic programs (Carvalho et al., 2003).The tropical arboreal species present striking differences regarding fruit size, number and size of seeds (Silva et al., 2007), so the biometry of fruits can be useful for taxonomic distinction, as doubts persist yet upon the most adequate number of species for the genus Acrocomia.
However, most botanical classifications are based only on morphological data, many of them presenting variation of genotype vs. environment nature.So, mistakes may occur, what demonstrates the importance of utilization of other techniques which could help to split species.The study of fruit anatomy is a valuable tool for the classification of the type of fruits and, consequently, for Taxonomy (Souza et al., 2012), for practically not varying under environmental interference, and can also provide valuable data for identification of plant products (Vaughan, 1960).The histochemical detection of substances in fruits is of great importance not only for taxonomy but also for identification of active principles and other substances which can be utilized by the industry (Dôres, 2007).The commercial value of the fruits and the types of industrial processes needed, for example, for extraction of oil are determined by the nature and anatomical structure of fruits (CETEC, 1983).
The studies of fruits involving species of Acrocomia are yet scarce.So, our work was carried out with the objective to characterize biometrically fruits of the three arboreal species of Acrocomia of highest commercial interest with occurrence in Brazil and with great potential for utilization in the other countries where they occur, as well as to characterize anatomically the mesocarp to verify which tissue and or structure of the mesocarp contains the oil and if it is possible to perform the quantification of such cells and or structures aiming its adoption as selection criterion for purposes of genetic improvement.

Sampling Area and Fruit Biometry
The chosen species of Acrocomia are in accordance with Lorenzi et al. (2010).The individuals selected for our study are from different regions of Brazil.The individuals of A. aculeata from two natural populations in a transition area between Cerrado and Mata Atlantic forest in the municipality of Itapira, São Paulo.The individuals of A. intumescens were collected from a population in an area of Atlantic forest in the metropolitan region of Recife, Pernambuco, and the plants of A. totai were selected from two native populations of the Pantanal in the municipality of Corumbá, Mato Grosso do Sul.We sampled 30 fruits at random from ten individuals of each population (Figure 1).According to Manfio et al. (2011), evaluation of four fruits in a population is sufficient to assess the studied characteristics.The fruits were measured as for their external longitudinal diameter (length), external transversal diameter (diameter) and individually weighed for determination of fresh mass and dry mass given by drying in oven with air circulation at 58 o C, until constant weight.The percentage of moisture in the pulp was obtained by difference between fresh mass and dry mass, divided by fresh mass (Moura, 2010).We calculated the length/diameter ratio (C/D) of the fruits, regarding that the ratio C/D < 1 indicates flat shape, C/D > 1 is ovoid, and the ratio C/D = 1 means globose (Sacramento et al., 2003).The obtained data were analyzed by univariate statistics, covering measures of position (medium, minimum and maximum) and of dispersion (standard deviation, coefficient of variation), as well as distribution of frequency.We performed analysis of variance (ANOVA) with Tukey's posttest, at 5% of probability.
The biometric characteristics of fruits of the studied species of Acrocomia were compared as for their diagnostic potential for taxonomy and genetic improvement, using groupment analysis.We analyzed the four main characteristics related to productivity: external longitudinal diameter, external transversal diameter, and fresh and dry masses.The data were distributed in classes and then tabulated in form of binary matrix described as presence (1) or absence (0) and then submitted to groupament analysis utilizing the algorithm UPGMA and the Euclidian distance as measure of similarity among sampling units using the software PAST (Hammer et al., 2001).The stability dos groupments was tested applying the procedure of resampling by 10000 bootstraps.

Morphoanatomy of the Mesocarp
Three fruits of each population were collected for analyses of anatomy, fixed with FAA 70 for 48 hours and stored in ethylic alcohol 70%.Next, we removed a small piece of the central region of the fruit with a band-saw and then dehydrated it in ethylic series.Afterwards, the material underwent a pre-infiltration in different concentrations of a solution of synthetic resin (Historesin ® Leica) and alcohol and then immersed in pure synthetic resin, sectioned in rotative microtome and stained with toluidine blue 0.05% in acetate buffer 0.1 M (pH 4.7) (O'Brien et al., 1964).We performed histochemical tests utilizing Sudan IV for detection of total fats (Pearse 1985), Lugol for detection of starch (Gerlach, 1984), Ruthenium red (Jensen, 1962) for detection of pectic substances, polysaccharides and acid mucilage and iron III chloride (Johansen, 1940) for detection of simple phenols.The documentation of the slides set of the optic microscopy was obtained under photomicroscope Olympus BX 51 with system and coupled image capture model DP71.

Biometric Characterization of Fruits
The fruits of A. aculeata and A. totai present different peel and pulp colors, even in individuals of the same population.The fruits of A. intumescens presented lower variation and are generally light green or yellowish when ripe.It is also possible to perceive visually the contrast of size among fruits of the different species (Figure 2  To demonstrate graphically the variability of characteristics within and between the studied species of Acrocomia, each measured characteristic was evaluated considering the data of the three species altogether and then determined classes of distribution of data.The data of absolute frequency are represented in the graphs by the columns and the relative frequency (%) of data distribution of each characteristic within each species is represented by lines (Figure 3).Regarding diameter, most sampled fruits belong to the class "large", between 4.0 and 4.7 cm.Although occurring overlap of part of the values in some points of the distribution, the separation of peaks is quite clear, i.e., of the highest frequency of each biometric characteristic within species in the distribution.Most fruits of A. aculeata (83.33%) have diameter considered large, A. intumescens most fruits (71.67%) with intermediate diameter (3.1 -3.9 cm) and A. totai has most fruits (95%) with small diameter, between 2.2 and 3.0 cm (Figure 3 a).
Concerning length, most part of data was concentrated in class "large", measuring 3.9 to 4.6 cm.As can be observed in Figure 3 b, there was data overlap of A. intumescens and A. totai, with great part of their fruits with "medium" size (3.0 to 3.8 cm).However, the highest frequency of fruit length in A. totai (58.33%) was concentrated in the class "small" with fruits measuring between 2.1 and 2.9 cm, and A. aculeata and A. intumescens with most fruits (73.33 and 56.67%, respectively) distributed in class "large".
Most sampled fruits, considering the three species together, presented fresh mass between 16.5 and 26.2 g, being represented in the class "light".There was overlap of part of the fruits of A. aculeata and A. intumescens (43.33%) in the class of fruits with fresh mass "medium", with weight between 26.3 and 35.9 g.In A. totai the fruits were distributed between the classes "very light" (6.9 -16.4 g) and "light", most part concentrated in the class "light" (53.33%).Most data of fresh mass of A. aculeata was concentrated in class "heavy" (45%) with fruits weighing between 40 and 45.5 g (Figure 3 c).In spite of the observed overlap of data of dry mass in the distribution of classes, the formation of three peaks is well evident, each one indicating the highest frequency of data of dry mass determined within each species (Figure 3 d).Acrocomia aculeata has most fruits in the class "heavy" (55%), with dry weight between 26.3 and 33.5 g.Acrocomia intumescens has the highest frequency of fruits (71.67%) with weight between 11.5 and 18.8 g concentrated in class "light", and A. totai presents most fruits in the class "very light" (78.33%), weighing between 4.1 and 11.4 g.
The morphological diversity both within and between analyzed species of Acrocomia was with utilization of the distribution in classes of the evaluated biometric characteristics.The variability within each species was explained by the presence of fruits in different classes of each characteristic.For example, A. aculeata has fruits distributed into four of the five classes established for fresh mass (Figure 3 c).The variability among species graphically demonstrated by the peaks of distribution of the biometric characteristics within each species, such as the diameter classes forming three peaks, each peak representing one well defined species, each one covering a certain class of distribution (Figure 3 a).
The highest mean fresh mass of the fruit was also found in individuals of  Acrocomia aculeata presents ratio C/D of 0.97 and A. intumescens and A. totai have 1.05, i.e., the fruits of the three studied species present ratio C/D close to 1, evidencing globose shape (Table 1).
The values can vary according to the ripening stage of fruits, form of harvest and preservation time.
Significant differences (p < 0.05) were detected among the means of length, diameter, fresh mass and dry mass of fruits, i.e., the obtained results rejected the hypothesis of equality among means, demonstrating the existence of biometric variation among species, A. aculeata standing out for the highest values for all cited biometric characteristics, A. totai, the lowest values and A. intumescens intermediate values (Figure 4).* Same letters do not differ statistically at 5% probability (p < 0, 05) test de Tukey.The four main biometric characteristics of fruits (diameter, length, fresh and dry mass) utilized for groupment analysis resulted in separation of the studied species of Acrocomia, as illustrated in Figure 5.
Figure 5. Groupment analysis obtained by Euclidian distance and UPGMA, based on the characteristics diameter, length, fresh and dry masses of fruits of the three studied species of Acrocomia.
The analysis resulted in closeness of A. aculeata and A. intumescens and separation of A. totai from both, what can be explained by the values remarkably lower of all evaluated biometric characteristics found in A. totai.Figure 3 illustrates that A. totai presents the peaks with highest frequencies of the samples of each evaluated characteristic well separated from the other species, and that A. aculeata and A. intumescens present some peaks of highest frequency of similar data, as well as overlap of samples in a same class, e.g.frequency distribution of length data (Figure 3 b), where A. aculeata and A. totai have the highest frequency in the same class "large".
The fruit biometry data support the classification of Acrocomia proposed by Lorenzi et al. (2010).The main morphological characteristics which distinguish the studied species of Acrocomia are summarized in Table 2 (Figure 6).
Table 2. Summary of the morphological characteristics of three species of Acrocomia.

Anatomy of the Mesocarp
The analyzed species of Acrocomia present similar morphoanatomy of the mesocarp, not representing a useful character for taxonomy of the genus (Figure 7 a-c).

a b c
The mesocarp is formed in most part by parenchymatic cells.Throughout the mesocarp can be observed large rounded cavities, with thin walls, irregularly distributed and frequently fused forming large spaces with irregular shapes (Figure 7 a-c).With the performed tests it was not possible to prove if these cavities (Figure 7 e, f) are the responsible for the high production of mucilage of the fruits, since the test for polysaccharides (Ruthenium red) was not positive.
All over the mesocarp are also found bundles of non-vascular fibers and vascular bundles, the latter being involved by sclerenchymatic sheath.The vascular bundles are of similar size and are irregularly distributed throughout the mesocarp (Figure 7 d).

Histochemical Tests
The performed histochemical tests were also similar as for presence and quantity of the tested compounds, only differing in starch content, detected in highest quantity in A. intumescens, followed by A. aculeata, but absent in A. totai, and the highest presence of phenolic compounds in A. aculeata and A. totai.The assessed compounds and their intensity are summarized in Table 3.
Table 3. Detected compounds in the mesocarp in the three species of Acrocomia.

Acrocomia intumescens
+ + Great quantity; -Not observed; + / -Observed in some individuals and not in others.

Total Fats
Practically all parenchymatic cells of the mesocarp in all studied species contain oil as evidenced by positive reaction to Sudan IV, so, all species present potential for extraction.Oil occurs in parenchymatic cells of the mesocarp in form of lipid bodies, also called oleosomes or lipid droplets, which can present varied sizes depending on the species and or stage of the studied fruit parts.These organelles synthesize and store triacilglycerols (TAGs), associated to proteins that delimit, i.e., compartimentamentalise the organelle, being responsible for the temporary storage and efficient of carbon of high energy (Horn et al., 2013, Ho et al., 2014).
In case of this work, the oleosomes could not be observed in sections in the mesocarp, probably due to immersion process of the material in synthetic resin.In hand cuts made on material only fixed was possible to observe such organelles, however, due to the large quantity and overlap of oleosomes present, it was not possible to see the parenchymatic cells individually as it was also not possible to count the oleosomes (Figure 8 a, b).However, if altering the immersion technique of the material and the type of microscopy is possible to quantify and even measure the size of oleosomes.Ho et al. (2014) made quantification and measurement of oleosomes present in the embryo, in the mesocarp and in the nut of the oil palm (Elaeis guineensis Jacq.), finding differences between quantity and size of such organelles depending on the tissue and its development stage, however, utilizing other fixation and inclusion techniques and with use of transmission scanning microscope (Figure 9).

Mucilage
Although not having being visualized with the use of Ruthenium red, the quantity of mucilage present in fruits of Acrocomia is very high.Although the mucilage is concentrated in large cavities in the mesocarp, due to its great quantity it can permeate the epicarp, what was proven by visualization of the mucilage in the pulp because the alcohol in which fruits were preserved became very viscose (Figure 8 c).
Mucilage is a macromolecular, complex carbohydrate, of varied composition (acid or neutral polysaccharides) according to the species, with hydrophilic properties (Sáenz et al., 2004).Due to its great capacity to absorb water, in whose presence it becomes viscose, acts in plants as a water reservoir (Cárdenas et al., 1998), having important physiological functions, such as reduction of transpiration in dry climates, water and nutritive substance storage, and protection against pests and pathogens (Alvarez et al., 1992;Fahn, 1979;Rocha et al., 2011).The production of mucilage in great quantity in fruits of Acrocomia spp.can suggest its role as adaptation to dry climates, where they are most frequent, or as chemical characteristic of species of the genus.Rocha et al. (2002), studying species of Hibiscus (Malvaceae) in xeric habitat, and Colonetti (2012), working on a cactus, verified the role of mucilage as storage substance and water retention.Yet, Silva and Potiguara (2009), analyzing the leaf histochemistry of Oenocarpus species (Arecaceae) from Amazonia, attributed the occurrence of mucilage, not to an ecophysiological adaptation, but to a probable characteristic of that palm group.

a c b d e f
Since it was not possible to detect mucilage with the use of Ruthenium red in samples of our study, utilized for detection of total polysaccharides and acid mucilage (Jensen, 1962), we suppose that the mucilage present in the mesocarp of the studied species of Acrocomia is predominantly neutral.Gregory andBaas (1989, apud Rocha et al., 2011) suggested that different types of mucilage exert distinct functions, where water storage would be made by the acid fraction, with production peak during the Summer months, and the neutral fraction of the mucilage would be responsible for build-up of carbohydrates, with peak during Winter.Such finding supports the hypothesis of the presence of mucilage in the mesocarp of Acrocomia species exerting the function of water storage and retention.This can be even more feasible considering biochemical and anatomical studies on A. aculeata fruit development, with peak of mucilage accumulation in the mesocarp until natural fruit abscission (Montoya, 2013, Reis et al., 2012).And we point out that the abscission phase of fruits of species of the genus, indicating ripeness, occurs during the warmer months in Brazil.
It is worth to highlight that mucilages, due to their viscose consistency in presence of water, have sticky and thickening properties, much utilized by the food industry in sweets and jams, and by the pharmaceutical industry for stability of emulsions and ointments, plus acting as dietetic fiber in the human organism promoting reduction of cholesterol, control of glycose, reduction of the risk of some types of cancer and of the symptoms of chronic constipation and hemorrhoids (Colonetti, 2012).I.e., the fruits of the species of Acrocomia, beside its use for oil extraction, due to the large quantity of mucilage present in the mesocarp can also be extracted and sold to different industrial segments.Furthermore, the process of demucilage, i.e., the extraction of mucilage from the plant tissue, can increase oil yield, as demonstrated by Speroni et al. (2015), who increased the efficiency of oil extraction by 30% after demucilage of flax seeds (Linum usitatissimum L.).

Starch
The Lugol test was only positive for A. intumescens and one individual of A. aculeata.Starch in these species was observed in the parenchymatic cells of the mesocarp.The amyloplasts are grouped in spheres, what was also observed by Bonin et al. (2008) in samples of A. aculeata from another region of the state of São Paulo (Figure 8  d).
Starch are natural polysaccharides, little soluble and of high molecular weight, formed by various sequences of amylose and amylopectin.Amylose is a linear polymer, and amylopectin is a well ramified macromolecule, spheric to elliptic (Salisbury & Ross, 1992).The shape of starch grains can be distinguished mainly by the quantity of amylose, since the higher the content of amylose in relation to amylopectin, more spheric are the starch grains (Bewley & Black, 1994).So, due to the spheric shape of the starch grains present in the studied species of Acrocomia, we infer that the quantities of amylose are higher, similar to the report by Silva and Potiguara (2009) who also found spheric starch grains in species of Oenocarpus (Arecaceae).This corroborates Tomlinson (1961) about the lack of morphological diversity of starch grains in Arecaceae, therefore it is not a useful character for taxonomic distinction in this botanical family.
According to Montoya (2013) and Reis (2012), the accumulation of starch in fruits of A. aculeata happens during all development phases, after fecundation of the ovule.Nevertheless, after the 36 th week post-anthesis there is a marked reduction of starch content and thereafter a linear increase in production and accumulation of oil, so presenting a relation between the degradation of starch and the synthesis of fatty acids after this phase (Montoya 2013), what is explained by the fact that the synthesis and storage of oil in plant tissues is directly related to the availability of stored polysaccharides, e.g.starch (França et al. 1999).Thus, we suggest that the fruits where starch was not detected would be in a more advanced phase, when the stored starch had already been converted into oil in the mesocarp.

Phenolic Compounds
We observed cells with phenolic compounds in all analyzed species.According to Santos (2012), the phenolic compounds present in the mesocarp of A. aculeata occur inside the idioblasts.The largest quantity of phenolic idioblasts occurred among the analyzed samples of A. aculeata and A. totai (Table 3 and Figure 8 e, f).Phenolic compounds have antimicrobial activity and exert action against herbivory (Rocha et al., 2011b;Swain, 1959).
Regarding economic potential, the phenolic compounds are the most abundant antioxidants in plants, because they can mitigate cumulative harms that can trigger several diseases (Rocha et al., 2013).Acrocomia aculeata stands out for its content of total phenolic compounds (Aragão, 2014;Rocha et al., 2013;Siqueira, 2012), supporting its potential use as fresh food or processed functional food.All detected compounds, beside oil, are liable to utilization by different industrial segments.
The description of the morphoanatomy of the mesocarp and the detection of the main biochemical compounds represent an important contribution upon fruits of Arecaceae, as there are not enough studies on structural organization of the vegetative organs and, moreover, of the reproductive organs.Ontogenetic studies of fruits of the other species of Acrocomia and of A. aculeata of different localities are needed to understand origin, function and organization of each tissue present in the fruits.Such studies could generate data which may could serve for taxonomic purposes, beside subsidize knowledge necessary for management for extraction of any fruit compound, for seed production and plant breeding.
The histochemical tests, in addition to demonstrate that the high oil content present in other species than A. aculeata can also be utilized for extraction, evidenced the presence of other compounds, such as starch, phenolic compounds and mucilage that can contribute not only in nutrition as well as raw material for different industrial segments.

Conclusions
The evaluation of biometry of fruits revealed the existence of morphological variation within and between populations and among the three species of Acrocomia aculeata, A. intumescens and A. totai, complementing data of plant morphology as well as confirming the hypothesis that the species are distinct.The morphoanatomy of the mesocarp of the analyzed species is similar.The mucilage in the mesocarp is responsible for water storage.Starch is stored until the fruit begins to ripen, when it is converted into oil.The oil present in the mesocarp occurs inside oleosomes.

Figure 1 .
Figure 1.Area of occurrence and collection points of the three studied species of Acrocomia in Brazil Photos Acrocomia aculeata : Berton, L.H.C.

Figure 2 .
Figure 2. Morphological variation of number of seeds, color of peel and color of pulp of: a Acrocomia aculeata, b A. intumescens and c A. totai.

Figura 3 .
Figura 3. Distribution of classes of data of diameter, length, fresh mass and dry mass of Acrocomia aculeata, A. intumescens and A. totai.
Acrocomia aculeata, Ai: Acrocomia intumescens and At: Acrocomia totai.The described data result from our observations and from the revision of Acrocomia byLorenzi et al. (2010).

Figure 6 .
Figure 6.Adult individuals of a Acrocomia aculeata, b A. intumescens and c A. totai.

Figure 8 .
Figure 8. Section of mesocarp in Acrocomia spp.: a oleossomes in the mesocarp, b detail of oleossome, c mucilage, d starch grains, e phenolic compounds detected with Ferric Chloride III, f cell with phenolic compound in detail, stained with toluidine blue.Bar: 100 µm (a, b, d, e), 1 mm (f)