3.1. Leaf shape
Simple in three taxa, namely, Hedera canariensis, M. denhamii, and Oreopanax guatemalensis; simple lobed palmate in H. helix and T.papyrifer; compound palmate in four species of Schefflera; and compound pinnate in three species of genus Polyscias, as shown in Fig. 1.
3.2. Stem and lamina anatomy
3.2.1. Stem investigation
Angled in seven taxa and terete in five taxa (H. helix, P. guilfoylei, P. scutellaria, S. actinophylla and S. pueckleri). All taxa are not glandular; glandular in H. canariensis; lenticel is present in six taxa (H. helix, M. denhamii, O. guatemalensis, S. elegantissima, S. pueckleri, and T. papyrifer). Collenchyma is absent in six other taxa, may be angular-lamellar in nine taxa, and is angular in M. denhamii, O. guatemalensis, and S. arboricola. As shown in Fig. 2, the aspect of vascular bundles is siphonostelic in 11 taxa and distinct in P. scutellaria.
3.2.2. Lamina anatomy
Raised adaxially in 11 taxa and flattened adaxially in S. actinophylla. All taxa are not glandular, peltate eglandular in H.helix, and multicellular branched eglandular in T. papyrifer. Collenchyma is annular in five taxa (H. canariensis, H. helix, P. fruticosa, S. actinophylla, and S. elegantissima), annular-lamellar in five taxa (M. denhamii, O. guatemalensis, S. arboricola, S. pueckleri, and T. papyrifer), angular-lamellar in P. guilfoylei, and angular in P. scutellaria. The vascular system is partially continuous in six taxa (H. canariensis, H. helix, O. guatemalensis, P. fruticosa, P. guilfoylei, and S. actinophylla) and distinct in six other taxa. As shown in Fig. 2, all taxa have druses-raphides, except druses in P. scutellaria.
3.3. Lamina vein architecture
The primary vein category is pinnate in six taxa (M. denhamii, O. guatemalensis, P. fruticosa, S. actinophylla, S. elegantissima, and S. pueckleri), suprabasal in H. canariensis, and H. helix, acrodromous (basal) in P. guilfoylei, suprabasal actinodromous in P. scutellaria, suprabasal actrodromous in S.arboricola, and palinactinodromous in T. papyrifer. The secondary vein category is brochidodromou in four taxa (H. canariensis, H. helix, P. guilfoylei, and P. scutellaria); reticulodromous in M. denhamii, and S. arboricola; festooned brochidodromous in O. guatemalensis, S. actinophylla, and S. pueckleri; weak brochidodromous in P. fruticosa; intramarginal vein in S. elegantissima; and interior (seven basal veins) in T. papyrifer. The tertiary vein is category random reticulate in seven taxa, alternate percurrent in four taxa (O. guatemalensis, P. fruticosa, P. guilfoylei, and P. scutellaria), and dichotomizing in S. elegantissima. The quarternary vein category is regular polygonal reticulate (RPR) in nine taxa, alternate percurrent in M. denhamii, dichotomizing in S. elegantissima, and absent in O. guatemalensis. The quinary vein category is RPR in five taxa (H. canariensis, H. helix, M. denhamii, S. arboricola, and T. papyrifer), dichotomizing in five taxa (P. guilfoylei, P. scutellaria, S. actinophylla, S. elegantissima, and S. pueckleri), and absent in O. guatemalensis, P. fruticosa as shown in Fig. 3.
3.4. Epidermal cell description
Cell shape was irregular in four taxa (H. canariensis, H. helix, M. denhamii, and T. papyrifer) and polygonal in eight taxa, anticlinal wall sinuous in four taxa (H. canariensis, H. helix, M. denhamii, and T. papyrifer), slightly curved in eight taxa, and stomatal shape elliptical in all taxa. The stomatal type is anomocytic and anisocytic in H. canariensis and H. helix, anisocytic in seven taxa, and anisocytic and diacytic in P. fruticosa, P. guilfoylei and S. elegantissima. The sculpture is ruminate in four taxa (H. canariensis, O. guatemalensis, S. actinophylla, and pueckleri); pusticulate in H. helix and M. denhamii; reticulate-aerolate in P. fruticosa, P. guilfoylei, and P. scutellaria reticulated in S. arboricola; favulariate in S. elegantissima and striate in T. papyrifer as shown in Fig. 4.
3.5. Molecular assessment
All primers were produced 78 bands and showed monomorphic and polymorphic bands (Table 3). Primer iPBS primer 2270 produced one monomorphic band and nine polymorphic bands (seven common and two unique), C1 produced one monomorphic band and 14 polymorphic bands (13 common and one unique), G4 produced one monomorphic band and 13 polymorphic bands (12 common and one unique), and PseCra5 produced no monomorphic band and 13 polymorphic bands (13 common). Although no unique bands were produced, PseLes1 produced no monomorphic and 13 polymorphic bands (13 common). Although no unique bands were produced, PseCra3B produced no monomorphic and 13 polymorphic bands (13 common), and no unique bands were recorded, as shown in Fig. 5.
Table 3
Type of bands and percentage of polymorphism of ISSR primers applied on the studied taxa of family Araliaceae.
Primer | Monomorphic bands | Polymorphic | bands | Total bands | Polymorphism % |
Common | Unique | |
iPBS primer 2270 | 1 | 7 | 2 | 10 | 90 |
C1 | 1 | 13 | 1 | 15 | 93.33 |
G4 | 1 | 12 | 1 | 14 | 92.86 |
PseCra5 | 0 | 13 | 0 | 13 | 100 |
PseLes1 | 0 | 13 | 0 | 13 | 100 |
PseCra3B | 0 | 13 | 0 | 13 | 100 |
3.6. Numerical analysis
Data from the whole plant, stem, and leaf anatomy for the examined taxa were amalgamated with data from lamina architecture and stomatographic analyses. They were subjected to numerical analysis to explain the relationship among the studied taxa based on 182 macro-micromorphological traits used for computation and produced a dendrogram, as shown in Fig. 6. Data extracted from ISSR analysis were subjected to numerical analysis to explain the relationship among the examined taxa based on 78 molecular traits. As shown in Fig. 7, these traits were used for computation and produced a dendrogram. Finally, data extracted from macro-micromorphological attributes were amalgamated with data from ISSR analysis. They were subjected to numerical analysis to explain the relationship among the studied taxa based on 260 macro-micromorphological and molecular traits used for computation and produced a dendrogram, as shown in Fig. 8.
The resulting dendrogram from morphological attributes was compared with current system treatments. The dendrogram shows that the taxa under investigation were split into two main series (I and II), three clusters (A - C), and five groups (Fig. 6A). Series I included only one cluster (A) and one group. Cluster A included one group of three studied species. Series II involved two clusters (B and C) and four groups. Cluster B involved two groups: the first group involved two studied species, whereas the second one involved four studied species. Cluster C involved two groups; the first group involved two studied species when the second one involved only one studied species. The interrelationships among these taxa are summarized as follows.
Series I: Group 1 includes H. canariensis, H. helix, and T. papyrifer. The results agreed with Harms (1894–1897) classification system that put them in the same tribe. Hutchinson (1967), Bentham (1867), and Tseng and Hoo (1982) placed them in different tribes. Calestani (1905) and Viguier (1906) placed T. papyrifer in the same tribe but H. canariensis, and H. helix in different tribes. Seemann (1868) placed T. papyrifer in the same family but a different tribe and placed H. canariensis, and H. helix in a different family.
Series II: Group 2 includes M. denhamii, and O. guatemalensis. The results agreed with the Harms (1894–1897) classification system that put them in the same tribe. Hutchinson (1967), Bentham (1867), Tseng and Hoo (1982), and Seemann (1868) placed M. denhamii in the same tribe but O. guatemalensis in a different tribe. Calestani (1905) and Viguier (1906) placed O. guatemalensis in the same tribe but M. denhamii in a different tribe.
Group 3 includes S. actinophylla, S. pueckleri, S elegantissima, and S. arboricola. The results agreed with Harms (1894–1897), Calestani (1905), and Viguier (1906) classification systems that put them in the same tribe. Hutchinson (1967), Bentham (1867), Seemann (1868), and Tseng and Hoo (1982) placed them in the same family but different tribes.
Group 4 includes P. fruticosa and P. guilfoylei. The results agreed with Bentham (1867), Seemann (1868), Harms (1894–1897), Calestani (1905), Hutchinson (1967), and Tseng and Hoo (1982) classification systems that put them in the same tribe. Viguier (1906) placed them in the same family but different tribes.
Group 5 includes P. scutellaria. The results agreed with Bentham (1867), Seemann (1868), Harms (1894–1897), Calestani (1905), Hutchinson (1967), and Tseng and Hoo (1982) classification systems that put them in the same tribe. Viguier (1906) placed it in the same family but a different tribe.