Leaf anatomy of the South African Danthonieae (Poaceae). V. Merxmuellera macowanii, M. davyi and M. aureocephala

Bothalia ◽  
1981 ◽  
Vol 13 (3/4) ◽  
pp. 493-500
Author(s):  
R. P. Ellis
Keyword(s):  
Light Microscopy ◽  
South African ◽  
Vascular Bundle ◽  
Leaf Anatomy ◽  
Related Species ◽  
Leaf Blade ◽  
Vascular Bundles ◽  
The South ◽  
Species Groups

Transverse sections and abaxial epidermal scrapes, of herbarium and freshly fixed leaf blade material, of Merxmuellera macowanii (Stapf) Conert, M. davyi (C. E. Hubb.) Conert and M. aureocephala (J. G. Anders.) Conert, were examined using light microscopy. The leaf anatomy o f these three species is very similar in all respects with the exception o f certain  M. aureocephala specimens. In addition, the anatomy indicates a relationship between these three species and M. disticha (Nees) Conert. This group of species differs anatomically from M. stricta (Schrad.) Nees, and related species such as  M. drakensbergensis (Schweick.) Conert and  M. stereophylla (J. G. Anders.) Conert, in the sequence of vascular bundles along the width of the leaf blade and associated characters. However, the M. aureocephala specimens, not having the  M. disticha type of vascular bundle arrangement, anatomically resemble the M. stricta group of species, and M. aureocephala appears to be intermediate between these two species groups.resemble the M. stricta group of species, and M. aureocephala appears to be intermediate between these two species groups.

Leaf anatomy of the South African Danthonieae (Poaceae). VI. Merxmuellera arundinacea and M. cincta

Bothalia ◽  
1982 ◽  
Vol 14 (1) ◽  
pp. 89-93
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Unique Feature ◽  
Transverse Section ◽  
Vascular Bundles ◽  
The South ◽  
First Order

The leaf blade anatomy and the abaxial epidermal histology of Merxmuellera arundinacea (Berg.) Conert and M. cincta (Nees) Conert are described and illustrated. These two species resemble one another morphologically and are the only representatives of the genus with open, expanded leaves. They are, nevertheless, clearly distinct anatomically, particularly in the structure of the leaf blade as viewed in transverse section. The anatomy of M. cincta is noteworthy in the possession of additional vascular bundles located immediately below the first order vascular bundles. This vertical arrangement of bundles at differing levels is a unique feature of M. cincta and possibly indicates a need for taxonomic adjustment.

Leaf anatomy of the South African Danthonieae (Poaceae). IV. Merxmuellera drakensbergensis and M. stereophylla

Bothalia ◽  
1981 ◽  
Vol 13 (3/4) ◽  
pp. 487-491
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Related Species ◽  
Leaf Blade ◽  
The South ◽  
Abaxial Epidermis ◽  
Closely Related Species

The leaf blade anatomy of  Merxmuellera drakensbergensis (Schweick.) Conert and  M. stereophylla (J. G. Anders.) Conert is described and illustrated. These two closely related species have virtually identical leaf anatomy—both the leaf in section and the abaxial epidermis. The close anatomical resemblance between these two species raises doubts about their specific status. This is especially significant when compared with the considerable differences observed between the anatomical ‘forms’ recognized in  M. disticha (Nees) Conert (Ellis, 1980) and M. stricta (Schrad.) Conert (Ellis, 1980a).

Leaf anatomy of the South African Danthonieae (Poaceae). VII. Merxmuellera dura and M. rangei

Bothalia ◽  
1982 ◽  
Vol 14 (1) ◽  
pp. 95-99 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Unique Feature ◽  
Transverse Section ◽  
Vascular Bundles ◽  
The South ◽  
First Order

The leaf blade anatomy and the abaxial epidermal histology of Merxmuellera arundinacea (Berg.) Conert and M. cincta (Nees) Conert are described and illustrated. These two species resemble one another morphologically and are the only representatives of the genus with open, expanded leaves. They are, nevertheless, clearly distinct anatomically, particularly in the structure of the leaf blade as viewed in transverse section. The anatomy of M. cincta is noteworthy in the possession of additional vascular bundles located immediately below the first order vascular bundles. This vertical arrangement of bundles at differing levels is a unique feature of M. cincta and possibly indicates a need for taxonomic adjustment.

Leaf anatomy of the South African Danthonieae (Poaceae). III. Merxmuellera stricta

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 191-198 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
Environmental Factors ◽  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Variable Species ◽  
Morphological Differences

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera stricta (Schrad.) Conert is described and illustrated. In this variable species four distinct anatomical “forms” are recognized viz. the typical  M. stricta form, the Cathedral Peak form, the Drakensberg form and the alpine form. The alpine and Cathedral Peak forms have recently been described as M. guillarmodiae Conert (1975). The degree of anatomical differentiation of these “forms” resembles the situation described in M. disticha (Nees) Conert (Ellis, 1980). Populations of both M. stricta and M. disticha from the Drakensberg mountains display extensive anatomical diversification which appears to be correlated with environmental factors. In addition, morphological differences are exhibited as well and the anatomical “forms” of M. stricta probably warrant taxonomic recognition.

Leaf anatomy of the South African Danthonieae (Poaceae). II. Merxmuellera disticha

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 185-189 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Taxonomic Status ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Environmental Requirements

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera disticha (Nees) Conert is described and illustrated. Three distinct anatomical “forms” are recognized viz. typical M. disticha, the Drakensberg form and the alpine bog form. These three anatomical groups also appear to have differing environmental requirements and probably warrant taxonomic status.

Leaf anatomy of the South African Danthonieae (Poaceae). XIII. Pentameris macrocalycina and P. obtusifolia

Bothalia ◽  
1984 ◽  
Vol 15 (3/4) ◽  
pp. 579-585
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
The South ◽  
Type Specimens ◽  
Distinct Genus ◽  
Close Relationship ◽  
A Minor

The leaf blade anatomy of Peniameris macrocalycina (Steud.) Schweick. and P. obtusifolia (Hochst,) Schweick. is described and illustrated. The leaf anatomy of these two species shows many similarities suggesting a close relationship between them. A slight problem appears to exist with the circumscription of P. obtusifolia and a minor taxonomic adjustment may result in a classification which agrees totally with that based on leaf anatomy. This would result in details of the leaf outline being diagnostic for these two taxa. The nomenclature of P. obtusifolia is also very confusing and clarification is needed by reference to the relevant type specimens. P. macrocalycina and P. obtusifolia together with  P. longiglumis (Nees) Stapf, appear to form a distinct genus and do not bear close anatomical resemblances to either P. thuarri Beauv. or P. dregeana Stapf.

Leaf anatomy of the South African Danthonieae (Poaceae). XIV. Pentameris dregeana

Bothalia ◽  
1986 ◽  
Vol 16 (2) ◽  
pp. 235-241
Author(s):  
R. P. Ellis
Keyword(s):  
Light Microscopy ◽  
South African ◽  
Leaf Anatomy ◽  
Representative Sample ◽  
Anatomical Structure ◽  
The Other ◽  
Herbarium Specimens ◽  
The South ◽  
Fixed Material

Transverse sections and abaxial epidermal scrapes of leaf blades of Pentameris dregeana Stapf, both of herbarium specimens and of freshly fixed material, were examined by light microscopy. The anatomical structure was found to be basically uniform in a representative sample. A few somewhat atypical specimens, how'ever, showed epidermal similarities with  Pentaschistis colorata (Steud.) Stapf. A comparison with other danthonoid grasses revealed some specimens identified as  Pentaschistis colorata var.  polytricha Stapf which resemble  Pentameris dregeana very closely in leaf anatomy. A definite gradation in leaf anatomy between  Pentameris dregeana and  Penta­schistis colorata appears to exist and. consequently, it is proposed that the affinities of Pentameris dregeana lie with this group of  Pentaschistis species rather than close to any of the other  Pentameris species.

Leaf anatomy of the South African Danthonieae (Poaceae). XVIII. Centropodia mossamedensis

Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 41-43
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
The Other ◽  
Photosynthetic Pathway ◽  
The South ◽  
Kranz Anatomy ◽  
Fixed Material

The leaf blade anatomy of Centropodia mossamedensis (Rendle) T. A. Cope [=  Asthenatherum mossamedense (Rendle) Conert] is described and illustrated. This description is based on freshly fixed material and confirms that this species has Kranz anatomy with the C4 photosynthetic pathway. The anatomy differs little from that of C.  glauca and both undoubtedly belong to the same genus which is justifiably separated from the other danthonoid genera.

scholarly journals Leaf anatomy of the South African Danthonieae (Poaceae): XIX. The genus Prionanthium

Bothalia ◽  
1989 ◽  
Vol 19 (2) ◽  
pp. 217-223 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
The South ◽  
Adaxial Epidermis

The leaf blade anatomy of Prionanthium dentatum (L. f.) Henr.,  P. ecldonii (Nees) Stapf and  P. pholiuroides Stapf is described and illustrated. The transectional anatomy is non-Kranz with diffuse chlorenchyma. The adaxial epidermis has dome-shaped stomata, dumbbell-shaped to nodular silica bodies and elongated microhairs. The three species differ in the presence or absence of macrohairs, abaxial stomata and marginal linear, sessile glands. The latter character is shared with Pentaschistis triseta (Thunb.) Stapf and its allies, and relationships with  Pentaschistis are indicated rather than with any other extant arundinoid genus.

Leaf anatomy of the South African Danthonieae (Poaceae). I. The genus Dregeochloa

Bothalia ◽  
1977 ◽  
Vol 12 (2) ◽  
pp. 209-213 ◽  
Author(s):  
R. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Generic Description

The anatomical structure, of the leaf blade as seen in transverse section, and the abaxial epidermis, of Dregeochloa pumila and  D. calviniensis is described and illustrated. A generic description is included and the relationships of the genus are briefly discussed.

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