Mrs. Zander’s Libelli Latini,

Sample Files, The Letter X
P. M. Eckel
Res Botanica
Missouri Botanical Garden
November 23, 2008
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Mrs. Zander’s Libelli Latini

Sample Files, The Letter “X”






X and x in Roman script correspond with the Greek xi, the 14th letter of the Greek alphabet.


The Greek xi is pronounced in English within a word like the ks in 'tacks' or the x in 'tax,' or 'wax' hence the xi represents a double consonant (compounded of gamma-s, kappa-s, and chi-s). When pronounced initially in a word, the xi is pronounced like the English z in 'zebra', as, for example, in 'xanthic.'


In Latin x is also a double consonant and arises out of the combination of c and s (dico, dixi), and g and s (lego, lexi).


X (xi), the 14th letter of the Greek alphabet, occurs in Greek dictionaries between the 'n' (nu) and short 'o' (omicron).In English dictionaries x comes between the w and the y. In Latin dictionaries it comes between the v and (y, if noted or) z.


x: in mathematics, the 'times' sign (6 x 2 = 12); also to express compared dimensions, as in two widths in a plank of wood: 'two by four' or 2 X 4 is a piece of lumber that, has two widths to one (unspecified) length, one width being 2 inches, the other 4; a leaf length may be compared to its width, as length (5-)4 (-2) x width (3-) 2 cm., the 'x' notation here is spoken as the preposition 'by' (as in 2 by 4, a plank of wood; 3 x 2 = 6, 'three multiplied 'by' 2 is 6)).


Roman numeral X stands for 10, or ten (decem, q.v.).


NOTE: In Spanish words, such as place names, the sound of the letter x is interchangeable with that of the letter j, hence in epithets the x and j appear to be interchangeable:

   Jalapa, Mexico; Loja, Ecuador:

   (Asteraceae):  Aster jalapensis Fernald; Hieracium jalapense Standl. & Steyerm.; Perymenium jalapanum Standl. & Steyerm.

   (Asteraceae): Baccharis xalapensis Kunth; Bartlettina xalapana (B.L.Turner) B.L.Turner; Eupatorium xalapanum B.L.Turner; Eupatorium xalapense Kunth

   (Asteraceae): Monactis lojaensis H.Rob.; Taraxacum lojoense H.Lindb.

   (Asteraceae): Baccharis loxensis Benth.; Cronquistianthus loxensis R.M.King & H.Rob.; Erigeron loxensis Hieron.; Eupatorium loxense Hieron.; Fleischmannia loxensis H.Rob.; Gnaphalium loxense Willd. ex Spreng.;


x: the basic haploid chromosome number of a taxon; n is the hapoid chromosome number of an organism. 2n is the diploid chromosome number of an organism, e.g. basic chromosome number in the Pottiaceae: x = 13. Some species of Pottia may have gametophyte chromosome numbers that can be much higher (usu. multiples of 13); see chromosome, chromosome number.


x (multiplication sign): see noth-, notho-.


-x: for names (nouns) ending in -x, see -ex,-egis, and -ix,-icis;

    The presumed declension of Glaux L. is Glaux,, Glaucis (s.f.III), dat. sg.  Glauci, acc. sg. Glaucem, abl. sg. Glauce [> Gk., glaucos,-e,-on, sea-green].

  NOTE: other nouns ending in -x include:

     -ex,-egis, q.v., such as grex (group);

     -ex,-icis, q.v., such as frutex (fruit); 

     -ix,-ichis, q.v., such as Acrothrix or generic names ending in -thrix;

     -ix, -icis, q.v., such as radix (root);

     -ux,-ucis, q.v., such as lux,, lucis, light;

     -yx,-ychis, q.v., such as bostryx;

     -yx, -ycis, q.v., such as calyx.


-x: some Latin adjectives end in -x:

      fallax, gen. sg. fallacis (deceitful, false, treacherous), dat. sg. fallaci, acc. sg. fallacem, abl. sg. fallacy; fugax,-acis (ready to flee, flying, transitory, fleeting).

      Also simplex, gen. sg. simplicis, q.v. (simple).


xanth-, xantho-,-xanthus,-a,-um (adj.A): in Gk. comp., yellow [> Gk. xanthos,-E,-on, yellow of various shades, golden or pale yellow; also red-yellow, chestnut, auburn (Liddell & Scott); syn. L. flavus, -a,-um (adj.A), q.v.;

    - chloroxanthus, greenish-wellow; xanthacanthus, with yellow spines or thorns; xanthocarpus, with yellow fruits; xanthocephalus, yellow-headed; xanthochymus, with yellow sap or latex; xanthophlebius or xanthoneurus,with yellow veins; xanthophyllus, with yellow leaves; xanthorrhizus, with yellow roots; xanthosphaerus, with yellow spheres or globes; xanthostephanus, with a yellow crown or garland; xanthostylus, with yellow styles; xanthotrichus, with yellow hairs.

    - xanthochlorus, yellowish-green; xanthochrous, yellow-colored; xantholeucus, yellowish-white, pale yellow; xanthophoeniceus, yellowish-red (scarlet); xanthoporphyreus, xanthoporphyrus, yellowish-purple.

   NOTE: a variant spelling in some words is zantho-, q.v.

Xantheranthemum, xanthos + Eranthemum; Xanthoceras,-atis (s.f.III), from the Greek words for yellow and horn, in allusion to the horn-like processes of the disk; Xanthorrhiza Marsh. Yellow Root, from Gk. xanthos, yellow and rhiza, root: alternative spelling Zanthorrhiza L'Hér., roots are a source of yellow dye; Xanthorrhoea, one species the source of Yellow Acaroid Resin used in the varnish industry; Xanthosoma, yellow body, in allusion to the yellow stigmoid disk;  Xanthoxylum Gmel., Gk. xanthos, yellow, and xylon, wood, alternative spelling to Zanthoxylum L.; Sect. Lecicia xanthococca Vain.; Xanthosoma (Araceae)


xanthellus,-a,-um (adj.A), xanthicus,-a,-um (adj.A), xanthinus,-a,-um (adj.A): yellowish, tending to a yellowish color.


Xanthisma,-atis (s.n.III), abl. sg. Zanthismate, a genus of plants with yellow flowers; X. gracile, X. gypsophilum, X. junceum, X. coloradense, X. glaberrimum; note that Stearn (1996) indicated that this genus is feminine. In the Index to Plant Names there occur epithets in both neuter and feminine. What the original gender of this genus is has not been determined here. DeCandolle is the original author and he is the authority for X. texanum, so presumably the author originally published the genus as a neuter noun.


-xanthic: see hapax-.


Xanthoxylum: Xanthoxylum,-i (s.n.II), abl. sg. Xanthoxylo.


xen-, xeno-: in Gk. comp. strange, stranger, derived from another individual [> Gk. xenos, a stranger];

    - xenogamia,-iae (s.f.I), xenogamia, fertilization between sexual elements borne by different individuals.


xenogamous, cross-fertilizing, fertilization involving gametes from different plants: xenogamicus,-a,-um (adj.A), xenogamus,-a,-um (adj.A), allogamicus,-a,-um (adj.A), allomicticus,-a,-um (adj.A), exogamicus,-a,-um (adj.A).


xer-, xero-: in Gk. comp., dry, as in withered structures [> Gk. xeros,-a,-on, dry; syn. L. siccus,-a,-um, dry]; cf. scariosus,-a,-um (adj.A) q.v.: scarious, i.e. of thin dry membranous texture and   not green, papery; opp. herbaceus,-a,-um (adj.A), q.v.

    - xerocarpus, with dry fruits; xeromorphus, xeromorphicus, structurally adapted for dryness; xerophilus, loving dry places, xerophilous, xerophilicous; xerophyticus, living in dry habitats; xerophyllus, with dry leaves, xerophyllous.

Xeranthemum, from Gk. xeros, dry and anthos, a flower, alluding to the persistent form and color of the dried flower heads; Xerobotrys Nuttall; Xerochloa R.Br.; Xerochlamys J. G. Baker; Xerocomus Quélet, a fungus; Xerocoprinus R. Maire, a fungus; Xerodiscus F. Petrak, a lichen; Xerophyllum, from Gk. xeros, dry and phyllon, a leaf, alluding to the dry, grass-like leaves that are tenacious and used by Indians to make water-tight baskets.


xerampelinus,-a,-um (adj.A): 'of the color of dry vine-leaves,' 'dull red with a strong mixture of brown' (Stearn 1983 sec. Lindley).

Vilfa xerampelina Trin; Russula xerampelina Fr.: a mushroom with the cap purplish red; Hieracium xerampelinum Johansson & Samuelsson.


xericus,-a,-um (adj.A): xeric, very dry; see hydric, mesicus,-a,-um (adj.A).


xero-, see xer-.


xerocleistogamicus,-a,-um (adj.A): xerocleistogamous, chasmogamous under normal conditions but cleistogamous during unusually dry periods.


xerophyticus,-a,-um (adj.A): xerophytic, dry, in reference to plants, vegetation, habitats; see hydric, xericus,-a,-um (adj.A), mesicus,-a,-um (adj.A).


Xerophyton,-i (s.n.II), abl. sg. xerophyto, nom. & acc. pl. xerophyta: a plant of dry, often hot places; see hydrophyton, mesophyton.


xiph-, xipho-: in Gk. comp., sword-like [> Gk. xiphos,-eos (s.n.III) a sword, in Homer described as large and sharp, and two-edged, but later it described a straight sword, as opp. to the sabre]; see 'sword-shaped;'

    - xiphodon,-ontis (adj.C), with sword-like teeth; xiphophyllus, -a,-um (adj.A), with sword-like leaves.

Xiphagrostis Coville in Safford, a grass; Xiphocarpus K. B. Presl, a bean; Xiphium, a Greek name for a Gladiolus, alluding to the sword-like leaves,(xiphion,-ii (s.n.II), the sword-flag);iphomyces Syd., a genus of fungi; Xiphophora C. Montagne, an alga; Xiphophyllum, a fossil gymnosperm; Ziphias,-adis, the genus of the swordfishes, type of family Xiphiidae; Xiphotheca Ecklon et Zeyher, a bean.


Xiphidion,-ii (s.n.II), abl. sg. xiphidio: a small sword.


Xiphion,-ii (s.n.II), abl. sg. xiphio; xiphium,-ii (s.n.II), abl. sg. xiphio: a small sword.

Bryoxiphium Mitten (Bryoxiphiaceae, Bryoxiphiales), the Sword-moss; Cylindroxyphium Bat. & Cif.; Dictyoxiphium W. J. Hooker. a fern; Schoenoxiphium C. G. D. Nees, Cyperaceae.


xiphoideus,-a,-um (adj.A): sword-like; see sword-shaped.


xuth-, xutho-: in Gk. comp. golden yellow (Stearn 1983)[> Gk. xouthos, golden yellow, akin to xanthos - a color between xanthos and pyrrus, yellowish tawny, dusky];

    - xuthanthus (adj.A) with yellow flowers; xuthochymus with yellow sap or latex; xuthocladus, with yellow shoots, xuthospermus, with yellow seeds, xuthosporus, with yellow spores.


xyl-, xylo-, -xylus (adj.A), -xylicus (adj.A); -xylum,-I (s.n.II), -xylon,-i (s.n.II): in Gk. comp., woody, relating to wood;

    - xylinus,-a,-um (adj.A) pertaining to wood, woody; xylogenus,-a,-

      um (adj.A), born or produced on wood; xylophilus,-a,-um (adj.A),

      woodloving, living on wood; xylorrhizus,-a,-um (adj.A) with woody

      roots or rootstock;

    - leucoxylus, leucoxylicus, leucoxylic, leucoxylous; melanoxylus,

       melanoxylicus, melanoxylous, with black wood; xanthoxylus,

      xanthoxylicus, with yellow wood. 

    - xylocanthus,-a,-um (adj.A), with woody spines (note the elision

      of the a-, otherwise xylacanthus.

    - xylobalsamum,-i (s.n.II), abl. sg. xylobalsamo: the wood of the

      balsam-tree; xylocassia,-ae (s.f.I), abl. sg. xylocassia, wood of

      the cassia, cassia-wood; xylocinnamomum,-i (s.n.II), abl. sg.

      xylocinnamomo, the wood of the cinnamon plant.

    - Xanthoxylum,-i (s.n.II) Gmel., abl. sg. Xanthoxylo, Gk. xanthos, yellow, and xylon, wood; Haematoxylum, Blood-wood; Carpoxylon,-i (s.n.II), abl. sg. Carpoxylo.

    - Xylobium: Greek xylon, wood and bios, life, alluding to the growth of plants of this genus on trees (Orchidaceae); Xylophylla L., in reference to a woody leaf, the true leaves in this genus obsolete and the branches are leaf-like; Xylosteum, from Greek xylon, wood and osteon, bone.

NOTE: as certain groups of fungi prefer wood as a substrate, a wide variety of fungal and lichen generic names begin with xyl- and xylo-: from Xylaria to Xylostroma.


Xylaria,-ae Hill ex Grev.(s.f.I), a genus of fungi responsible for root rot of hardwoods (X. digitata), black root rot of apple (X. hypoxylon), an invader of mushroom beds (X. vaporaria, X. pedunculata).


Xylem, the wood elements of a vascular bundle, possessing tracheal tissue (Jackson): xylema,-atis (s.n.III), xylemate; cf. phloem, phloema,-atis (s.n.III).


Xylinum,-i (s.n.II), abl. sg. xylino: cotton.


Xylographia,-ae (s.f.I), xylographia: woodcut.


Xyloma,-atis (s.n.III), xylomate: xylome "(of Dothideales), a sclerotium-like body producing sporogenous structures inside (de Bary)" (Ainsworth & Bisby).


Xylon,-i (s.n.II), abl. sg. xylo: timber, log, wood, particularly the cotton-tree of Pliny [> Gk. xylon, wood].


Xylopodium: xylopodium,-ii (s.n.II), xylopodio.


-xylus,-a,-um, -xylicus,-a,-um: see xyl-.


Xyris,-idis (s.f.III), abl. sg. xyride: the wild iris of Pliny [> Gk. xyris]; 'Greek name of some plant with 2-edged leaves, from xyron, a razor' (Fernald 1950).


xysm-, xysmo-, xysma-, xysmat-, xysmato-: in Gk. comp. 'filings, shavings [> Gk. xysma,-atos (s.n.III), also xysmE, that which is scraped or planed off, filings, shavings.

Xysmalobium (Asclepiadaceae), Yakhop, a genus of food plants. This appears to be the only genus that uses this prefix. Asclepias xysmalobioides S. Moore.


Xystus,-i (s.m.II), abl. sg. xysto: a long and open portico used for athletic exercises in stormy weather by ancient Greeks and Romans; a walk lined with trees [> Gk. xystos, scraped, polished, from its smooth floor].

Possibly the fungal genus Xystozukalia Theiss (= Limacinia) uses this word as a prefix.