A Grammatical Dictionary of Botanical Latin

Aestivation, estivation, “the manner in which the parts of a flower are folded up before the flower expands” (Lindley); the arrangement of flower parts (floral envelopes) in the bud, the manner in which the parts of a flower are folded up before expansion (Jackson) (vernation, q.v. is the arrangement of leaves in the bud, (perhaps from vernus, spring): aestivatio,-onis (s.f.III), abl. sg. aestivatione [> L. aestivus,-a,-um (adj.A), summer, when flowers mostly appear]; praefloratio,-onis (s.f.III), abl.sg. praefloratione.

- limbus corollae pelviformis, mutabilis, in aestivatione ruber, sub anthesi violaceus et priusquam corolla decidit caeruleus, the limb of the corolla saucer-shaped, changeable, in bud red, at anthesis violet and before the corolla falls blue (Stearn).

- stylus elongatus, aestivatione inflexus (B&H), style elongate, inflexed at aestivation.

- petala cum sepalis alterna iisque breviora, ad basin disci inserta, in aestivatione aperta, sub anthesi erecta, petals alternating with the sepals and shorter than these, at the base of the disc inserted, in aestivation open, at anthesis erect (Stearn).

- stamina 10 vel plura, nunc numerosissima, filamentis in laminam ligulatam angustam valde elongatam aestivatione circinatam connatis apice liberis (B&H), stamens 10 or more, sometimes very numerous, with filaments connate into a ligulate narrow strongly elongate at aestivation circinate blade, [the filaments] free at the apex.

- limbus corollae in aestivatione ruber, sub anthesi violaceus et priusquam corolla decidit caeruleus, limb of corolla in bud red, at anthesis violet and before the corolla falls blue.

"The term aestivatio for the arrangement of the parts of calyx or corolla in the flowerbud was introduced by Linnaeus in 1762 (cf. vernation.) (Stearn).

Praefloratio,-onis (s.f.III), abl. sg. praefloratione: “the arrangement of the parts of the flower when unexpanded” (Lindley) = aestivation.

The following is mostly from Stearn 1984): [aestivation] is said to be:

open (aestivatio aperta) when the parts do not touch one another;

- calycis tubus discifer elongatus; segmenta 5, angusta, subaequalia, aestivatione aperta, tube of the calyx bearing a disc, elongate; segments 5, narrow, subequal, with the aestivation open.

- calyx late cupularis, margine obsolete lobato v. latere fisso, persistens, aestivatione subaperta (B&H), calyx broadly cupulate, with the margine faintly lobate or laterally divided, persistent, with the aestivation subaperta.

valvate (aestivatio valvata, valvaris) when the parts touch along their margins or edges but without overlapping;

- sepala distincta, herbacea v. rarius petaloidea, imbricata v. valvata v. in calycem valvatum rarius imbricatum coalita, ab ovario libera (B&H), .sepals separated, herbaceous or more rarely petaloid, imbricate or valvate or fused into the valvate more rarely imbricate calyx, free from the ovary.

calycularis,-e (adj.B): (aestivatio calyculatus or calycularis) “(obsol.) a term of aestivation, when the outer bracts of an involucre are much shorter than the inner” (Lindley).

conduplicate, folded together lengthwise along the middle, complanate, also conduplication (conduplicatio,-onis (s.f.III) “a term of aestivation; when the sides of an organ are applied to each other by their faces” (Lindley): conduplicatus,-a,-um (part.A), q.v.

induplicate (aestivatio induplicativa) when the margins are bent abruptly inwards and their outer faces touch without overlapping;

- vernatio ab omnibus affinibus differt folio juniore secus costam induplicato lamina interiore dorso gemmae applicita (B&H), the vernation differs from all related [species] by the young leaf along the costa induplicate, with the inner lamina on the back attached to the bud.

reduplicate (reduplicativa) when the margins are bent abruptly outwards and their inner faces touch without overlapping; see reduplicate;

- calyx tubo obconico, cum ovario connato, lobis 5 patentibus aestivatione reduplicatis (B&H), the calyx with an obconic tube, the tube connate with the ovary [with a connate ovary], with lobes 5 spreading reduplicate in aestivation.

imbricate: when the parts overlap, the aestivation may be simply imbricate (aestivatio imbricata), the parts overlapping parallelly at the margins;

imbricativus,-a,-um (adj.A): “overlapping at the edge only; a term of aestivation” (Lindley); “1. overlapping as the tiles on a roof; 2. in aestivation, used of a calyx or corolla where one piece must be wholly internal and one wholly external, or overlapping at the edge only = syn. imbricate” (Jackson); see imbricate.

quincuncial (quincuncialis; quincuncialiter imbricata) when of five parts two have their margins both inside, two with margins both outside, one with one margin inside and the other outside; quincuncialis,-e (adj.B): “a kind of aestivation, in which out of five parts two are exterior, two interior, and the fifth covers the interior with one margin, and has its other margin covered by the exterior; as in the calyx of the Rose” (Lindley);

- sepala nunc distincta imbricata v. rarius valvata, nunc in calycem saepius parvum lobis dentibusve imbricatis apertis v. rarius valvatis coalita (B&H), the sepals are sometimes separated, imbricate or more rarely valvate, sometimes fused into the calyx, more often small, with lobes or teeth, imbricate, open or more rarely valvate.

cochlear (aestivatio cochlearis; cochleari-imbricata) when one part being larger than the rest and hollowed like a spoon covers all the rest, of which one will be totally inside and the other three with one margin inside and one outside;

vexillary (aestivatio vexillaris) when one part, the vexillum or standard, is much larger than the others and is folded over them, they being face to face, so that the posterior part overlaps the lateral parts and the lateral parts overlap the anterior parts;

ascendent (aestivatio ascendens; ascendenti-imbricata), like vexillary aestivation but with anterior parts overlapping the posterior ones;

alternative (alternativa) when the parts are in two whorls, the outer parts cover and alternate with the inner parts;

contorted or twisted (contorta, torsiva, convoluta) when each part successively overlaps the one in front and is overlapped by the one behind so that each part has an inner covered margin and an outer exposed margin, the direction being to the right (dextrorsum) or to the left (sinistrorsum) as viewed form the outside (cf. clockwise, twining);

corrugated or crumpled (corrugata) when the parts are folded irregularly together in every direction.

plicate: in plicate aestivation (aestivatio plicata) the whole organ (calx or corolla) is not divided into parts but folded and sometimes also twisted lengthwise;

Examples from Stearn:

- sepala 5 libera in aestivatione quincuncialiter imbricata, sepals 5 free in aestivation quincuncially imbricate;

- calyx 5-lobus, lobis in aestivatione valvatis, calyx 5-lobed, with lobes in aestivation valvate.

- petala in aestivatione cochleari-imbricata, petals in aestivation cochlear;

- corolla infundibuliformis limbi quinquepartito laciniis per aestivationem contortis vel valvatis, corolla funnel-shaped with the limb 5-parted with the segments during aestivation contorted or valvate.

- corolla lobis aestivatione varie imbricatis nec plicatis nec valvatis nec regulariter contortis, corolla with lobes at aestivation variously imbricate not plicate not valvate not regularly contorted.

- corolla limbo patente, lobis saepius contorto-imbricatis, sese invicem nunc dextrorsum nunc sinistrorsum (ab exterior spectanti) obtegentibus, in directione contraria vel rarius in eadem directione curvis et in alabastro tortis vel fere rectis, rarissime valvatis, corolla with limb spreading, with lobes very often contorted-imbricate, by one another in turn at one time to the right at another time to the left (from the out-side viewed) overlapping, in direction opposite or very rarely in the same direction curved and in bud twisted or almost straight, most rarely valvate.

- corollae loborum aestivatio helicte (sinistrorsum sensu Eichleri) contorta, si imbricata lobo mediano externo, aestivation of the lobes of the corolla helictically (sinistrorsely in the sense of Eichler) contorted, if imbricate then the middle lobe outside. (Stearn 1983).

NOTE: aestivation is also “the state or condition of torpidity or dormancy induced by heat and dryness of summer (as in certain snails) - opp. hibernation” (WIII). Note that in hibernation, the resting state of spores and plants occurs in winter; see hibernation.