MANUAL OF THE GRASSES OF THE UNITED STATES 



245 



allies may be divided into three 

 groups. The group with 7 chromo- 

 somes (probably the most primitive) 

 includes einkorn (T. monococcum L.). 

 The group with 14 chromosomes in- 

 cludes durum wheat ( T. durum Desf.), 

 poulard wheat (T. turgidum L.), 

 Polish wheat (T. polonicum L.), 

 emmer (T. dicoccum Schrank), and 

 also T. pyramidale Perciv., T. orient- 

 ale Perciv. (not Biebers. 1806), T. 

 persicum Vavilov (not Aitch. and 

 Hemsl. 1888), T. dicoccoides Koern. 

 and T. timopheem (Zhukov.) Zhukov. 12 

 The group with 21 chromosomes in- 

 cludes spelt and the commonly culti- 

 vated wheats referred to as T. vul- 

 gare Vill. and T. compactum Host, 



also T. macha Dekap. and Menab. 

 and T. sphaerococcum Perciv. 12 Alaska 

 wheat is a variety of poulard wheat 

 with branched heads. It is also known 

 by several other names, such as 

 Egyptian, miracle, and mummy. This 

 variety is considered inferior com- 

 mercially to standard varieties of 

 wheat. Stories of varieties originating 

 from seed found with mummies 3,000 

 years old have no basis in fact. 



The origin of wheat is not known, 

 as there is no native species like any 

 of the cultivated forms. Some bota- 

 nists have suggested species of 

 Aegilops and others T. dicoccoides 

 Koern., a wild species of Palestine, 

 as the possible ancestor. 



44. AEGILOPS L. Goatgrass 



Spikelets 2- to 5-flowered, solitary, turgid or cylindric, placed flatwise at 

 each joint of the rachis and fitting into it, the joints thickened at the summit, 

 the spikelets usually not reaching the one above on the same side, exposing 

 the rachis; spike usually disarticulating near the base at maturity, falling 

 entire, or finally disarticulating between the spikelets. Annuals with flat 

 blades and usually awned spikes. Type species, Aegilops ovata. Name from 

 Aegilops, an old Greek name for a kind of grass. 



The species of Aegilops have been recently introduced into the United 

 States and in some places are becoming troublesome weeds. At maturity the 

 spikes fall entire, the lowest rachis joint serving as a pointed callus to the 2- to 

 several-j ointed, strongly barbed fruits, which work their way into the mouths 

 and noses of grazing animals and into the wool of sheep. 



Spikelets subovate; rachis not disarticulating. .„. 3. A. ovata. 



Spikelets cylindric; rachis finally disarticulating. 



Glumes with 1 awn 1. A. cylindrica. 



Glumes with 3 awns. - — - -- 2. A. triuncialis. 



1. Aegilops cylindrica Host. 

 Jointed goatgrass. (Fig. 329.) Culms 

 erect, branching at base, 40 to 60 

 cm. tall; blades 2 to 3 mm. wide 

 spike cylindric, 5 to 10 cm. long 

 internodes of rachis 6 to 8 mm. long 

 spikelets 8 to 10 mm. long, glabrous 

 to hispid; glumes several-nerved, 

 keeled at 1 side, the keel extending 

 into an awn, the main nerve of the 

 other side extending into a short 

 tooth; lemmas mucronate, those of 

 the uppermost spikelets awned like 

 the glumes; awns very scabrous, those 

 of the upper spikelets about 5 cm. 



12 These names supplied by W. J. Sando, geneticist. 



long, those of the lower spikelets pro- 

 gressively shorter. O — Weed in 

 wheatfields, and waste places, New 

 York, and Pennsylvania; Indiana to 

 Wyoming and Utah, south to Texas 

 and New Mexico; Washington; re- 

 cently introduced from Europe. 



2. Aegilops triuncialis L. Barb 

 goatgrass. (Fig. 330.) Culms branch- 

 ing and spreading at base, 20 to 40 

 cm. tall; blades rather rigid, sharp- 

 pointed, spreading; spike 3 to 4 cm. 

 long, 2 or 3 of the lower spikelets 

 often reduced, the fertile spikelets 3 

 to 5; glumes with 3 strong scabrous, 

 somewhat spreading awns, 4 to 8 



