41 
nerves in the upper part minutely scabrous, lanceolate in outline, gradually 
tapering from below the middle toward the apex, and 7-10 mm. long exclu- 
sive of the awn which in the lowermost florets may reach 24 mm. in length. 1 
Prior to 1838, however, Link, in Hortus Reg. Bot. Berol., II, pages 
189-190 (1833), described two species collected by Richardson in North 
America, viz. Triticum trachycaulum and T . subsecundum, as follows: 
“28 TV. trachycaulum. Folia plana rigidiuseula stricta scaberrima. Spica longiu- 
scula, spiculae 5-7 florae. Valvae septemnerviae acutatae. Valvula ext. aristato acutala — 
Semina ex itinere in Americam borealem occidentalem attuit elar. Dr. Richardson nobisque 
dedit. 
T. Gramen ad 4 pedes in horto altum. Caulis superne pilis brevibus rigidis asper- 
rimus. Vaginae scabrae striatae, ligula vix nulla sed auricula ad oram vaginae; lamina 
ped. cireiter longa sulcata asperrima 3 lin. lata. Spica ad ped. longa; spiculae 8 lin. longae; 
valvae valvulis parum breviores; valvulae exter. laeves superne in nervis aristaque asperae, 
arista lin. longa.” (Plate IV). 
“29. Tr. subsecundum. Folia plana striata scabra. Spica longa, spiculae subsecundae 
triflorae, flosculo terlio pedicellato. Valvae multinerviae aristatae valvulis (arista excepta) 
longiores. Valvula ext. longe arislata — Semina quoque ex itinere in Americam borealem 
occidentalem attuit cl. Dr. Richardson nobisque dedit. T. Gramen 4-5 ped. altum. 
Vaginae laeves, ligula brevis truncata, lamina longiuscula ad 4 poll, longa ad 3 lin. lata sat 
scabra. Spica 5-6 poll, longa; spicae approximatae appressae, ita conversae, ut aristae in 
uno latere emincant, ceterum appressae; flosculus tertius abort iens, pedieello 2-3 lin. 
longo tenui incluso. Valvae ad lin. longae valde scabrae, aristae 3 lin. longae. Valvula 
externa parum ultra 2 lin. longa, arista poll, longa; valvula interior longitudine exterioris 
(exc. arista) obtusa apice hirta, nervo submarginali ciliato. Parapetala ex ovato lanceolata 
obtusiuscula glabra. Germen apice hirtum. An genere distinguendum? Tunc Critho- 
pyrum voeaverim.” 2 (Plate V). 
Through the kindness of Dr. L. Diels, Director of the Botanic Garden 
and Museum, Berlin-Dahlem, the author has had an opportunity to 
examine the types of the two species. Triticum trachycaulum Link is 
identical with what is generally known as Agropyron tenerum Vas., i.e. it is 
a plant with glabrous sheaths, green spikes and foliage, very short-awned 
lemma, the awn ranging from 1-2 mm., and with the nerves of the lemma 
minutely scabrous toward the apex. In the description the empty glumes 
are said to be 7-nerved, but in the type at Berlin they are as often 5-6- 
nerved. In any event, the exact number of nerves is varying, and may be 
influenced by soil and other conditions. Thus, as mentioned in the pre- 
ceding, while in specimens of A. tenerum in the wild state the nerves of the 
empty glumes normally are at least 4 or 5, starved specimens may occasion- 
ally have only 3. On the other hand, cultivated specimens grown under 
more favourable conditions may often display an unusually great number of 
nerves on the glumes. Through the courtesy of Mr. R. I. Hamilton, the 
writer has had the opportunity to examine a large number of pure-bred 
strains of A. tenerum grown at the Central Experimental Farm, Ottawa. 
This examination has revealed the presence of a larger number of nerves 
than is normally found in specimens growing in their natural habitat. 
Thus 7-nerved glumes are frequently found, and occasionally even 8-nerved. 
Triticum subsecundum Link is identical with T. Richardsoni Schrad. 
The type is a plant with glabrous sheaths, green spikes and foliage, and an 
awned lemma, the awn in the upper spikelets reaching a length of 20-30 
mm. The anthers are about 1 mm. long when empty. 
‘The writer is greatly indebted to Dr. A. W. Hill, Director, Royal Botanic Gardens, Kew.fora detailed descrip- 
tion of the type which ia preserved in the Herbarium of the Botanic Garden, Leningrad. 
*The writer is indebted to Professor Fernald for copies of the descriptions. 
