22 BULLETIN 772, TJ. S. DEPAKTMENT OF AGRICULTURE. 
Tribe 14, Tbipsaceae. 
Spikelets unisexual, the staminate in pairs, or sometimes in threes. 
2-flowered, the pistillate usually single, 2 -flowered, the lower floret 
sterile, imbedded in hollows of the thickened articulate axis and fall- 
ing attached to the joints, or inclosed in a thickened involucre or 
sheath or, in Zea, crowded in rows on a thickened axis (cob) ; glumes 
membranaceous or thick and rigid, awnless; lemmas and palea 
hyaline, awnless. Plants monoecious. 
This small tribe of seven genera is scarcely more than a subtribe 
of Andropogoneae. It is also known as Maydeae. 
Key to tlie genera of Tripsaceae. 
la. Staminate and pistillate spikelets in separate inflorescences, the first 
in a terminal tassel, the second in the axils of the leaves 2 
2a. Pistillate spikes distinct, the spikelets embedded in the hardened 
rachis, this disarticulating at maturity 142. Etjchlaena. 
2b. Pistillate spikes grown together forming an ear. the grains at 
maturity much exceeding the glumes 143. Zea. 
lb. Staminate and pistillate spikelets in separate portions of the same 
spike, the pistillate below 3 
3a. Spikes short, the 1 or 2 flowered pistillate portion inclosed in 
a beadlike sheathing bract 144. Corx. 
3b. Spikes many-flowered, the pistillate portion breaking up into 
several 1-seeded joints; no beadlike sheathing bract 141. Tbipsactjm. 
DESCRIPTIONS OF THE GENERA. 
1. BAMBOSEAE, THE BAMBOO TRIBE. 
1. ABUXDrNABiA Michx. 
Spikelets few to many flowered, large, compressed, the rachilla 
disarticulating above the glumes and between the florets ; glumes un- 
equal, shorter than the lemmas, the first sometimes wanting ; lemmas 
acute or acuminate or mucronate, faintly many-nerved: palea about 
as long as the lemma, prominently 2-keeled. 
Shrubs or tall reeds, with woody perennial branching culms, flat 
blades with petioles articulate with the sheaths, and loose racemes 
or panicles. Species about 25, in the Tropics of both hemispheres; 
2 species in the southeastern United States. 
Type species: Arundinaria macrosperma Michx. 
Arundinaria Michx., Fl. Bor. Amer. 1 : 73. 1803. One species described. 
Miegia Pers., Syn. PI. 1:101. 1805. A single species, based on Arundinaria 
maorosperma Michx., is included. 
Macronax Raf., Med. Repos. ser. 2. 5 : 353. 1808. Based on " The Arundi- 
naria of Michaux." 
Our two species, Arundinaria tecta (Walt.) Muhl. (fig. 1) and A, 
macrospernna (PL I), are the only native representatives of the tropi- 
cal tribe Bamboseae, or Bambuseae, the bamboos. Our species are 
known, respectively, as small and large cane. Both flower infre- 
