A Grammatical Dictionary of Botanical Latin

dimidiate: “when one half an organ is so much smaller than the other as to seem as if missing. Hardly different from oblique, except in degree. Also slit half-way up” (Lindley); halved, half, applied to a whole which is divided or split into halves; whereas dimidius is applied to a half; (in mosses) split on one side as in calyptrae which are dimidiate and hooded (cucullate, q.v.); (in mosses) “split; e.g. the calyptra split on one side (see cucullate)” (Magill 1990): "with one part of an organ so much smaller than the other that only half of the whole organ seems present; divided through the middle; actually halved, with the outer wall or perithecium covering only the upper half" (Stearn); (in fungi) “appearing to lack one half, or having one half very much smaller than the other; (of a pileus) without a stalk and semicircular; (of gills) stretching only halfway to the stipe; (of a perithecial wall), having the outer wall coverng only the top part” (Ainsworth & Bisby): dimidiatus,-a,-um (part. A) [> L. dimidio,-atum, 1. to divide into two equal parts, to halve]; cf. cucullatus,-a,-um (adj.A), mitrate;

- calyptris distincte dimidiatis, with the calyptrae distinctly dimidiate [i.e. split on one side].

- formae autem calyptrae tres observantur: conica s. [seu] campanulata; mitraeformis basi lobata et dimidiata (Mueller), however, three forms of the calyptra are observed: conic or campanulate; mitriform, lobed at the base, and dimidiate [i.e. split on one side].

- calyptra tenera fuscata dimidiata partem capsulae magnam obtegens, calyptra delicate, darkened, divided through the middle (on one side), covering over a large part of the capsule.

- pileus subdimidiatus substipitatus spongioso- suberosus tomentoso-substrigosus, pileus nearly divided in half, somewhat stipitate, spongy-corky, tomentose-substrigose.

- drupa carnosa, globosa, viridis, pericarpii strato exteriore 2-4-valvi deciduo, interiore dimidiato rubro succulento evalvi 2-lobo (B&H), drupe fleshy, globose, green with the outer layer of the pericarpium 2-4-valved, deciduous, the inner halved, red, succulent, lacking valves 2-lobed.

- discus depressus, tubum calycis late vestiens, crenatus, aequalis v. subdimidiatus (B&H), the disc depressed, widely covering the tube of the calyx, crenate, equal of somewhat halved [i.e. divided into halves].

- arillus carnosus, coloratus, integer dimidiatus v. cupularis (B&H), aril fleshy, colored, entire, split on one side or cup-shaped.

- semen oblongum, testa nitida basi arillo carnoso adnato dimidiato aucta (B&H), seed oblong, with the test shining augmented at the base by an adnate, dimidiate[i.e. split in half], fleshy aril.

- semen oblongum, basi arillo adnato dimidiato suffultum (B&H), seed oblong, subtended at the base with an adnate, aril [split into halves].

- pileus infundibuliformis, regularis, mesopus; attamen propter situm arcte caespitosum, exemplis plerumque pluribus imbricatis , haud raro etiam plus minus dimidiatus et pleuropus (S&A), the pileus funnel-shaped, symmetrical, the stalk attached in the middle; and yet due to the manner of lying [i.e. the site] caespitose, usually in many imbricate specimens, not rarely also dimidiate [ i.e. stretching only halfway to the stipe, or with the pileus appearing semi-circular]; and with a lateral stipe.

- acheniis fuscis striatis glabris dimidiato-calyculatis, with the acenia fuscous, striate, glabrous dimidiate-calyculate.

- calyptram, ab auctoribus consociatis Hooker et Greville calymperoideam basi thecam amplectentem et lateraliter fissam deliniatam, etsi nobis haud visam, Syrrhopodontis dimidiatam habemus (Mueller), the calymperoid calyptra illustrated by the [co-]authors Hooker and Greville, enfolding the theca and laterally split, I am considering the dimidiate [calyptra] of Syrrhopodon, even if not seen by us [i.e. by me].

- [fungi] sphaerulae parvae, fragiliusculae, vetustiorum paucae dimidiatae (S&A), the sphaerules small, somewhat fragile, a few of the older ones halved [perhaps semicircular].

dimidiato-cordatus,-a,-um (adj.A): “when the larger half of a dimidiate leaf is cordate” (Lindley), i.e. when, in a cordate leaf, one half is larger than the other.

dimidiato-lacer,-era,-erum (adj.A): lacerate or torn halfway through;

- [fungi] sphaerulis fragilibus demum passim dimidiato - laceris (S&A), with sphaerules fragile, in the end everywhere halfway-lacerate.

dimidiato-ovatus,-a,-um (adj.A): ovate, but with one half larger than the other;

- stipulae amplae, foliaceae, late dimidiato-ovatae, falcatae (B&H), the stipules big, leafy, broadly dimidiate-ovate, falcate.

half (adj.): dimidius,-a,-um (adj.A) half (in reference to one of both halves), dimidiatus,-a,-um (part.A) (in reference to the whole divided or parted into two halves).

mitrate, mitre-shaped, mitrate, mitriform: “having the form of a mitre; that is to say, concical and not slit on one side; in opposition to dimidiate” (Lindley).

[lichens]: divided through the middle; actually halved, with the outer wall or perithecium covering only the upper half" (Stearn); (of a pileus) without a stalk and semicircular:

Arthopyrenia dimidiata, a lichen with the wall of the perithecium dimidiate.