Under & Verboom, Generic limits in the Rytidosperma complex 
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12. Lemma indumentum on back; absent (0); scattered (1); tufted, at least top row 
(2)[nonadditive]. 
Abaxial lemma surface indumentum has been central in the controversies surrounding 
the generic delimitation within the Dantiwnia-Rytidosperma group of danthonioid 
species. We distinguish firstly between marginal hairs, which are usually visible as a 
long, continuous line along the lemma margins (Fig. 4: A), and abaxial lemma surface 
indumentum (Fig. 4: B-G). The latter is either scattered, generally in internerve rows 
(Fig. 4: E), or more or less tufted (Fig. 4: B-D, G). As noted by Jacobs (1982), there are 
intermediate forms. We regard the indumentum as tufted if tufts formed along the 
upper margin of the indumentum. At one extreme all indumentum is grouped into 
compact tufts, arranged into two transverse rows. These tufts are located between the 
nerves, resulting in 10 tufts if the row is complete. In several taxa only marginal 
(Fig. 4: D), or marginal and central (Fig. 4: B), tufts are present. The lower row is often 
diffuse, or may not be developed at all. When only the marginal tufts of the upper and 
lower row are present, this approaches the situation described as marginal hairs, but 
may be distinguished by the presence of two, rather than a single, marginal tuft (cf. 
Fig. 4: A, D). We made our observations on whole-mounts of the lemmas, using 
transmitted light — it may be more difficult to distinguish the different states using 
incident light on unstained material. 
13. Lemma indumentum lower row: complete (0); only lateral tufts present (1). 
14. Lemma lower indumentum row: tufted (0); diffuse (1). 
15. Lemma indumentum below the upper row: forming a short felt (0); longer 
and straggly (1). 
16. Lemma indumentum upper row: complete (0); lateral and dorsal tufts (1); two lateral 
tufts (2); only lateral tufts (3)[nonadditive]. 
17. Lemma indumentum lateral strips; absent (0); present (1). 
18. Upper lemma tufts: longer or equal to lobes (0); shorter than lobes (1). 
19. Lemma awn: absent or very short (0); long (1). 
Lemma awns are rarely totally absent, but there is a clear interval between awns which 
are generally shorter than the lobes (Fig. 4: E), as compared to well developed awns, much 
exceeding the lemma lobes. For the purposes of this character, the awns were not divided 
into the basal columns and the apical setae. 
20. Lemma awn: longer than the lemma setae (0); shorter or as long as the setae (1). 
21. Palea keels: not reaching apex (0); reaching apex (1). 
Palea keels stopping short of the palea apex appears to be a synapomorphy of the 
Pentaschistis clade, and is associated with almost straight, glabrous or sparsely scabrid 
keels. In the rest of the danthonioid grasses the keels are strongly developed and dilate, 
with margins incurved. These keels are sinuose, curving outwards in the middle, 
especially when the caryopsis is mature. 
22. Palea length: = lemma (0); » lemma (1). 
23. Palea shape: narrow, less than 1/3 as wide as long (0); broad, at least 1/3 as wide 
as long (1). 
24. Palea keels: glabrous to sparsely scabrid (0); densely scabrid or dilate (1). 
25. Palea keels: straight (0); curved (1). 
26. Palea midcells: rectangular (0); inflated (1). 
Generally the epidermal cells in the middle of the palea are rectangular, similar to the 
cells in other parts of the plants. However, in a few species of Rytidosperma the cells are 
inflated, and look quite distinct in surface view. 
