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

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.

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 191-198 ◽  
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 185-189 ◽  
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 41-43
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1989 ◽  
Vol 19 (2) ◽  
pp. 217-223 ◽  
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1977 ◽  
Vol 12 (2) ◽  
pp. 209-213 ◽  
Author(s):  
R. Ellis

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.


Bothalia ◽  
1988 ◽  
Vol 18 (1) ◽  
pp. 101-104 ◽  
Author(s):  
R. P. Ellis

The leaf blade anatomy of Urochlaena pusilla Nees is described and illustrated. The transectional anatomy is non- Kranz with diffuse but uniformly distributed chlorenchyma. The abaxial epidermis has dome-shaped stomata, dumbbell­shaped silica bodies, elongated finger-like microhairs, and cushion-based macrohairs may or may not be present. This type of arundinoid anatomy closely resembles that o f  Tribolium Desv.,  Chaetobromus Nees,  Schismus Beauv., and certain species of Pentaschistis Stapf.  Urochlaena pusilla is very similar to  Tribolium utriculosum (Nees) Renv. in leaf anatomy and these two species appear to be closely related.


Bothalia ◽  
1981 ◽  
Vol 13 (3/4) ◽  
pp. 493-500
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1982 ◽  
Vol 14 (1) ◽  
pp. 89-93
Author(s):  
R. P. Ellis

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.


Bothalia ◽  
1984 ◽  
Vol 15 (3/4) ◽  
pp. 573-578 ◽  
Author(s):  
R. P. Ellis

The leaf blade anatomy of  Pentameris thuarii Beauv. is described and illustrated. It is shown that the leaf anatomy of  P. thuarii bears little resemblance to the anatomy of  P. macrocatyciiw (Steud.) Schweick..  P. obiiisifolia (Hochst.) Schweick., P. longiglumis (Nccs) Stapf or P. dregeana Stapf. The leaf anatomy of P. thuarii was found to correspond closely with that of some specimens of Pentaschistis pallescens (Schrad.) Stapf, P. silvatica Adamson and P. lonuosa (Trin.) Stapf. The morphology of these  Pentaschistis specimens needs to be compared with that of  P. thuarii in order to establish whether the true relationships of  P. thuarii lie with these taxa. Anatomically. P. thuarii does not appear to be closelv related to anv species presently classified in Pentameris.


Bothalia ◽  
1984 ◽  
Vol 15 (3/4) ◽  
pp. 561-566
Author(s):  
R. P. Ellis

The leaf blade anatomy of Pseudopentameris macramha (Schrad.) Conert and P. brachyphylla (Stapf) Conert was studied both in transection and in surface view and is illustrated by means of photomicrographs. The leaf anatomy is typically danthonoid. T he abaxial epidermis consists of inflated, hexagonal long cells and stomata and micro-hairs are absent. Adaxial micro-hairs were observed. The creation of a new genus to accommodate these two species appears justified but certain species in  Pentameris Beauv.,  Merxmuellera Conert and Pentaschistis Stapf show similarities to Pseudopentameris and consideration should be given to their inclusion in Pseudopentamem.


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