Linder & Verboom, Generic limits in the Rytidosperma complex 
623 
27. Palea flaps: glabrous (0); hairy (1). 
The palea indumentum may be separated into two characters. The first character (27) describes 
the presence of long hairs between the palea margin and the keels. This indumentum is 
somewhat variable: in some species only a few hairs are present, while in others a dense 
indumentum may be formed. In very few species is the presence or absence of this 
indumentum variable. The second character (28, below) describes the presence of an 
indumentum bebveen the keels. Almost invariably, this indumentum is located in the lower 
half of the palea, often as a small hairy patch (Fig. 4: U). 
28. Hairs between palea keels: absent (0); scattered (1). 
29. Lodicule apex: truncate (0); lobed (1); tri-lobed (2)[nonadditive]. 
Lodicule shape and indumentum was surveyed by Tomhnson (1985), and our observations 
are consistent with her results. Observations have to be made at anthesis, as lodicule shape 
changes from before to after anthesis. Care has to be taken with observations on lodicule 
indumentum, as the bristles and microhairs appear to be readily lost on worn lodicules. 
Tlie density of the lodicule indumentum is somewhat variable between species, but not 
enough observations have been made to allow this character to be used (Fig. 4: M-P). 
30. Lodicule microhairs: absent (0); present (1). 
31. Lodicule bristles: absent (0); present (1). 
32. Anthers: white to orange (0); red (1). 
The three species of ]oycea are readily distmguished by their large, red anthers. For neither 
colour nor size is there an absolute interval between Joycea and the other groups, but the 
combination appears to be unique. However, for a number of species there are no 
observations on the anther colour. This character needs a more comprehensive survey, 
which would have to be based on live plants. 
33. Hilum shape: linear (0); punctiform (1). 
The shape of the hilum was used by Zotov (1963) to delimit Rytidospenna, but his reliance 
on this character was critized by Blake (1972) and Jacobs (1982). It is a complex character 
(Fig. 4: H-L), composed of the actual shape, as well as the length of the hilum relative to 
the total caryopsis length. In general, in Rytidosperma the hilum is less than 40% of the 
length of the caryopsis. In Danthonia and Plinthanlhesis the hilum is distinctly linear (Fig. 4: 
I, j), in most species of Rytidosperma it is ovate (Fig. 4: K, L), while in some species (especially 
in Knrroochloa and Schismtis (Conert and Tiirpe 1969,1974)) it is punctiform. We coded the 
relatively short, ovate or punctiform hila as 'punctiform'. The hila of joycea are intermediate 
in shape and length. 
34. Leaf in transverse section: non nodular (0); nodular (1). 
35. Islands of colourless cells: absent (0); present (1). 
These islands are situated in the chlorenchyma between the vascular bundles, and are 
variable in shape (Fig. 5: K). Care has to be taken to distinguish islands from holes in the 
chlorenchyma resulting from poor preservation or careless sectioning. 
Fig. 4. (left) Variation in floret and caryopsis morphology. A-G: abaxial lemma surfaces, showing 
variation in indumentum patterns, venation patterns, and the development of awns and setae. 
A, Danthonia unispicata (Crampton 1999); B, Notodanthonin penicitlata (Pullen 3034); C, N. alpicola 
(Craven 1633); D, Rytidosperma nitens (Moscal 1283); E, Plinthanthesis paradoxa (Austin 20); 
F, Notochtoe microdon (Linder 5633); G, Knrroochloa tcnclla (Compton 2882). H-K: outline of caryopsis, 
indicating the hilum shape and size. H, R. corinum (Dmce CHR 402035); I, Notochloe microdon 
(Vickery NSW 18041); J, D. nipinn (Richter 336); K, T. longifolia (McKee 9701); L, P. paradoxa (Ingwerson 
s.n.). M-P: lodicule morphology, indicating the general shape, from cuneate to tliree-lobed, venation 
patterns, and indumentum of micro- and macrohairs. M, Notochloe microdon (Linder 5633); N, R. 
nitens (Moscal 1283); O, D. unispicata (Crampton 1999); P, N. penicillata (Pullen 3034). Q-W: view of 
outside of palea, including callus and rhachUla intemode. Q, Notochloe microdon (Linder 5633); R, N. 
pcniciUnta (Pullen 3034); S, R. nitens (Moscal 1283); T, R. thomsonii (MacMillan p567); U, N. tenuior 
(Linder 5587); V, P. paradoxa (Austin 20); W, D. unispicata (Crampton 1999). Scale bar = 1mm. 
