222 PATAGONIAN EXPEDITIONS: BOTANY. 



KEY TO THE SPECIES. 

 A* Leaves glabrous. 

 b. Panicle contracted. 



c. Leaves as long as the culm. 



d. Culm tall, I meter. Sheaths long. Spikelets 6-8-flowered. Glumes woolly at 



base. alopecurus. 



d2. Culm 80 cm. Leaves filiform. Spikelets 3-flowered. Glumes subvillous. 



bonariensis. 

 d$. Culm 30 cm., shorter than the convolute leaves. Ligules long ; sheaths dilated. 



Awn short. controversa. 



d^. Culms in clumps, I meter ; lower leaves taller, subconvolute. Panicle spike-like. 



Spikelets 4-flowered. Floriglume bifid, mucronate-awned. forsteri. 



C2. Leaves shorter than culms, sheaths overlapping Annuals or biennials, under 30 cm. 



Spikelets 3-7-flowered. 

 d. Cauline leaves 3, flat or conduplicate, abruptly acute; ligules 2.5 mm. Spikelets 



3-7-flowered. annua. 



d2. Leaves convolute. Ligules obsolete. Spikelets 5-7-flowered. denudata. 

 d-$. Leaves convolute-pungent. Ligules short, obtuse. Panicles spike-like. Spike- 

 lets crowded above, 2-4-flowered, amethystine. robusta. 

 ^3. Leaves distichous, linear, rigid ; ligules short. Panicle lobed ; spikelets 2-5 -flowered, 



the staminal effete. Culm 20 cm. Flowers woolly at base. lanigera. 



c\. Leaves narrow or involute, with two yellow spots ; ligules oblong. Culms 30 cm., 



from a creeping base. Spikelets 5-io-flowered, with subfloral tufts, lanuginosa. 

 c$. Leaves short. Culms 15 cm. 



d. Culm 2-nodal below, with intravaginal innovations. Ligules 2 mm. Spikelets 



3-flowered. Glumes and floriglume subequal, keeled. atropidiformis. 



d2. Culm basally bulbiferous. Ligules long. Panicle few-spicate. Spikelets 2-3- 



flowered. Palea cuspidate-awned. ibari. 



c6. Leaves convolute, attenuate-pungent. Dioecious perennial. Spikelets 7-8-flowered, 



not villous. Culm 60 cm. argentina. 



cj. As c6, but leaves pungent ; floriglume woolly at base. bergii. 



c8. Leaves short, stiff and pungent, mostly distichous. Culm smooth, erect, slender. 



Spikes strict, secund. 



d. Leaves subterete. Spikelets 2-flowered, the upper flower male. erinacea. 

 d2. Leaves very conduplicate. Spikelets 2-flowered, both perfect, often with a rudi- 

 ment of a third. pugionifolia. 

 eg. Leaves very long, acute, smooth. Panicle long, rays rough. Spikelets 1 2-flowered, 



pale yellow. Culm 60 cm. pallens. 



b2. Panicle lax. Leaves sheathing ; with long ligules. 



c. Low, 6 cm. Leaves rigid, convolute. Spikelets few, 3-flowered. Glume and rachis 



glabrous. pumila. 



c2. Culm 60 cm., sheathed half way. Leaves distichous. Spikelets 4-6-flowered, 



cottony. , yaganica. 



63. Panicle lax. Culms 2-3 meters tall. Leaves fan-shaped, gracefully diverging. 



flabellata. 



