50 



P. R. \WCHERLEY 



P. alpina var. vivipara has 2n = 26, 33 ± 1 (Muntzing, 1940), 35 (Tutin, 1952) and 

 42 + 4ff, 44 (Flovik, 1938). P. X jemtlandica has 2n = 37, (39) (Nygren, quoted by A. 

 & D. Love, 1948). 



7. The Viviparous Deschampsiae 

 7.1. Historical outline 



Linnaeus (1753, 1, 64-5) named Aira cespitosa and A. alpina. The characters 

 given for the former were flat leaves, a spreading panicle and short straight awn, but 

 in A. alpina the leaves were described as subulate, the panicle as thick and the glumes 

 as silvery with a very short awn. These were synonymous with species 63 and 69 in 

 the Flora Suecica (1745, 23 and 26). The further details were given that sp. 63 (A. cespitosa) 

 has a /3 variety found in wet places in Lappland and whose long thin panicle is often 

 viviparous. Thus the first mention of vivipary in this genus was for a variety of A. cespitosa. 



The character given by most subsequent authors as the mark of A. alpina is the 

 dorsal insertion of the awn above the middle of the lemma, i.e. not basal as in A. cespitosa. 

 Linnaeus however, did not discuss the point of insertion ; it can only be inferred from the 

 statements that the awn is short in A. cespitosa and very short in A. alpina. No mention 

 of vivipary in A. alpina was made. 



A note by Davies was quoted by Smith (1800, 85) that a viviparous variety of A. 

 caespitosa (note changed spelling) is found in alpine places. Smith (1811) received from 

 Don viviparous plants from Clova and a seminiferous plant from near Dundee, which 

 were named A. laevigata. The main characters are that roughness is confined to the 

 lamina edges, the base of the floret is bearded, but the rhachilla is very short and smooth 

 (in A. cespitosa the rhachilla is long and hairy). A. laevigata bears culms a month earlier 

 than A. cespitosa, is usually viviparous and never attains more than a foot in height. 



P. de Beauvois (1812) split the genus Aira and designated the group including 

 A. cespitosa and A. alpina as Deschampsia. The following viviparous forms are given 

 by Roemer & Schultes (1817, 685 et seq.) : D. cespitosa Beauv. y var. alpina, D. alpina 

 (L.) Roem. & Schult. and D. laevigata (Sm.) Sm. In 1824 (p. 105) Smith states that A. 

 laevigata is within A. alpina L., which is now D. alpina. 



Roemer & Schultes defined the insertion of the awn on the lowest lemma in D. alpina 

 as somewhat below the open bifidity. Further details given were : the awn scarcely 

 projects beyond the glumes, the upper lemmas bear terminal awns, the back and edges 

 of the glumes are smooth. These features contrast with the sub-basal awn insertion 

 and scabrid glume keels in D. cespitosa. The leaves of D. alpina are said to be short, 

 always rolled, yellow-green and subulate. 



Discussing the Deschampsia section of Aira, Syme (1872, 63-6) gave a variety y 

 pseudalpina (Syme's spelling was Pseud- alpina) of A. cespitosa, which is distinguished 

 from the main form by smoother panicle branches and larger spikelets which are nearly 

 always viviparous. He then described A. alpina L., stating that the panicle branches are 

 smooth, the keels of the glumes are sometimes rough towards the apex but otherwise 

 smooth and the awn is from about the middle of the lemma. He observed that all his 

 specimens of A. alpina were viviparous and this species had often been confused with 

 A. cespitosa var. pseudalpina. He considered the presence or absence of roughness on the 

 lower portion of the glume keels the key to distinguishing the viviparous forms, and the 

 point of insertion of the awn the main point for distinction of D. alpina from D. cespitosa. 



Later it will be seen that difficulties arise because the state of the awn in viviparous 

 forms other than D. alpina has never been defined, and the lower portion of the glume 

 keels is quite smooth in all viviparous plants met with in this study. 



Druce (1888) mentions D. cespitosa Beauv. var. pseudalpina (Syme). This is the 



