tzihuactli.

Headword: 
tzihuactli.
Principal English Translation: 

a small agave with a spiny flower stalk; it has a soft edible fruit, and its roots have a medicinal value (Florentine Codex); it could be made into an arrow (Matrícula de Huexotzinco); it had associations with the Chichimecs and the Otomi (see attestations); it was also a personal name

Orthographic Variants: 
tzohuactli
Attestations from sources in English: 

See the Digital Florentine Codex for a number of references to tzihuactli.
https://florentinecodex.getty.edu/search?term=tzihuactli&view=text&filters=

"tzihuactli, variante *tzohuactli. (W.Lehmann 1938,57).
Sorte de petit maguey. Launey II 232. Cf. aussi Launey II 298.
Eine dornige, im Gebirgsland der Chichimeken wachsende Planze [a thorny plant that grows in the Chichimec mountainous region]. SGA II 452-453.
Le tzihuactli et le necuametl sont des plantes épineuses caractéristiques des steppes du nord. Christian Duverger, L'origine des Aztèques, p.172.
'in ômpa onoqueh in yâômicqueh necuametl, tzihuactli, mizquitlah', and where the war dead were, there were the magueys, the tzihuactli plants, the mezquite groves. Sah3,49.
Identité inconnue mais la plante est décrite parmi les cactées et les agaves dans Sah11,218.
SGA II 452 met 'tzihuac' en relation avec le verbe 'tzicoa', 'ergreifen, packen, festhalten' [seize, hold].
Illustration. Codex de Florence. Dib./Anders. XI fig. 752."
Wimmer 2004, from the Gran Diccionario Náhuatl, https://gdn.iib.unam.mx/diccionario/tzihuactli

"itoca, tzivactli in juhquj metontli yoan in jqujioio, chapactontli, mamae, mapipitzaoac, vitzio, qujioio, xiloio; qualonj, paoaxonj: in jxiloio necutic, ixconj: in jqujioio, piaztic, viac, chachaquachtic, tetecujtztic, qujioti, chachaquachivi; mana motlamjna. IN TZIVACTLA tlaovican, ovican. = Its name is tziuactli. It is like a small maguey, and its stems are a little drooping. It has leaves, slender leaves. It has spines, it has stems, it has a silk. It is edible; it can be cooked in an olla. Its silk is sweet; it can be baked on a griddle. Its stems are slender, long, rough, scabrous. It forms a stem, becomes rough, extends, shoots out. THE TZIUACTLI PATCH is a place of danger, a difficult place.
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 11, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 218.

in oc tzivactla = those still in the cacti
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 11, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 249.

tzivactla = patches of brambles
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 258.

tzivactli = thorny shrubs
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 210.

notzivaqujmju = thorny arrow
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 2, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 210.

spine(s) (late sixteenth century, Tetzcoco?)
Ballads of the Lords of New Spain: The Codex Romances de los Señores de la Nueva España, transcribed and translated by John Bierhorst (Austin: University of Texas Press, 2009), 32.

"...according to Seler (Collected Works, 11, Pt. 3-4, p. 56), it is probably a thorny plant found in the Chichimec highlands; he cites Hernández to identify it as a cactus with cylindrical stem. 'It is, therefore, the national weapon in the hand of the god of the Otomi.'" Later they say (sounding very different): "It is like a small maguey, and its stems are a little drooping.... Its stems are slender, long, rough, scabrous. It forms a stem, becomes rough, extends, shoots out." And they translate it as a "bed of twigs" in one place and "cacti" in another.
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 1, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1950), 47.

Attestations from sources in Spanish: 

"...al parecer, la palabra tzihuactli puede significar “blanco”, como en tzihuaccopalli, “copal blanco” (Sahagún, 2000: 819)"
Guilhem Olivier, Cacería, sacrificio y poder en Mesoamérica, 2015.

"...Hernández le da el nombre de " te-tzihuactli " (tzihuactli de las rocas) y se contenta en decir que es un cacto con tallo cilíndrico, acanalado."
Boletín de la Sociedad Botánica de México, Issues 1-17,p39, 1944.