A Grammatical Dictionary of Botanical Latin

Placentation, “the manner in which the placenta is constructed or placed” (Lindley); “the arrangement or mode of attachment of the placentas and ovules in a plant ovary: placentatio,-onis (s.f.III), abl.sg. placentatione; see placenta;

- CANELLA et CINNAMODENDRON propter placentationem parietalem a nobis juxta Bixaceas collocantur (B&H), Canella and Cinnamomodendron, due to the parietal placentation, by us is placed next to Bixaceae.

In a simple pistil:

- placentatio submarginalis, abl. sg. placentatione submarginali: submarginal placentation: occurring in a simple pistil.

- ovarium 1-loculare, placentis e basi loculi oriundis, in medio loculo inter se, rarius dorso cum parietibus, connatis (B&H), the ovary 1-locular, with the placentae arising from the base of the locule, connate between each other, more rarely [connate] on the back with the walls.

- capsula elongata, teres, 1-locularis, carpellis valviformibus margine placentiferis (B&H), the capsule elongate, round-cylindrical, 1-locular, with the carpels valviform, bearing placentas on the margin.

In a compound pistil, two or more carpels are used in various ways:

- placentatio parietalis (adj.B), abl. sg. placentatione parietali: parietal placentation, with carpels united by their adjacent margins and the ovules disposed along the inner ovary walls;

- placentae parietales (B&H), the placentae parietal.

- carpella in ovarium uniloculare coalita, placentis totum parietem obtegentibus (B&H), the carpels unilocular, fused in the ovary, with the placentae covering over the entire wall.

- ovulis oo per totum parietem creberrime dispositis (e carpellis oo compositum, placentis parietalibus confluentibus) (B&H), with the ovules [indeterminate, numerous] very closely arranged over the whole wall (composed of an [indefinite number] of carpels, with the placentae parietal, confluent).

- placentatio axilis (adj.B), abl. sg. placentatione axili: axile placentation, when the carpels are folded inward and the ovules occur along the central axis of the ovary;

- ovarium saepissime inferum, placentis in axi confluentibus (B&H), the ovary most often inferior, with the placentae confluent [i.e. running together] on the axis.

- ovula in quoque loculo nunc numerosa, placentis medio septo v. axi adnatis v. peltatis affixa (B&H), ovules in each locule sometimes numerous, attached to the placentas by a middle septum or adnate to the axis or peltate.

- placentatio centralis libera, abl. sg. placentatione centrali libera: free central placentation, when the ovules are arranged on a central column in the compound ovary, which lacks septa (lamellae) or the septa occur only at the base;

- placentae centrales liberae (B&H), the placentae central, free.

- ovula placentis centralibus, rarius parietalibus affixa, micropyle infera (B&H), the ovules attached to the central placentae, more rarely to parietal placentae, with the micropyle below.

- placentatio basalis (adj.B), abl. sg. placentatione basali: basal placentation, when the ovules are positioned on a low column at the ovary base;

- ovarium nunc 1-loculare placentis parietalibus, nunc 2-oo-loculare placentis basilaribus liberis v. axi centrali adnatis (B&H), the ovary sometimes 1-locular with the placentae parietal, sometimes 2-[indeterminate]-locular, with the placentae basal, free or adnate to the central axis.

- cf.: columna placentigera brevissima (F. Mueller), the placenta-bearing column very short.

- placentatio laminalis (adj.B), abl. sg. placentatione laminali: laminal placentation, when the ovules are scattered over the inner surface of the carpels;

- placentis semel v. basi bis 2-fidis laminis valde' involutis affixa (B&H), with the placentas once or at the base twice 2-fid, attached to the strongly involute laminae.

- capsula valvis nunc placentas centrales liberantibus, nunc saepius margine plus minus involuto v . intus intra marginem v. superfice fere tota placentiferis (B&H), the capsule with valves sometimes freeing the central placentas, sometimes more often with the margin more or less infolded or inside between the margin or almost the whole surface placentiferous.

- placentatio lamellata, abl. sg. placentatione lamellata: lamellate placentation, when the ovules are placed on thin extensions (lamellae or septa) of the placentae into a compound ovary;

- varium septatum placentis ángulo interno loculorum affixis (B&H), ovary septate with the placentae attached to the inner angle of the locules.

- ovarium imperfecte septatum, placentis e carpellorum marginibus intromissis (B&H), the ovary incompletely septate, with the placentae introduced from the margins of the carpels.

- ovarium syncarpicum, inferum, semiinferum v. calycis tubo inclusum, rarius exsertum, 1-loculare, placentis parietalibus v. septis a latere v. prope parietes placentiferis divisum, rarius perfecte septatum (B&H), the ovary syncarpic, inferior, half-inferior or included with the tube of the calyx, more rarely exserted, 1-locular, with the placentae perietal or separated by placentiferous septa from the side or near the walls, more rarely completely septate.