A Grammatical Dictionary of Botanical Latin

Umbel (Eng.noun), “an inflorescence in which the flower expands centripetally and their stalks radiate from a common point. (also) (obsol.) the pileus of certain Fungals” (Lindley); “ an inflorescence, properly indeterminate, in which a cluster of pedicels spring from the same point, like the ribs of an umbrella” (Jackson); "a racemose type of inflorescence with greatly abbreviated axis and elongate pedicels. In a compound umbel the branches are again umbellately branched at the summit" (Gleason 1952), 'an inflorescence in which the peduncles or pedicels of a cluster spring from the same level' (Fernald 1950), the inflorescence may be flat-topped or convex, the pedicels arising from a generally common point, as in the ribs of an [inverted] umbrella; it may be seen as a highly condensed raceme:

umbella,-ae (s.f.I), abl.sg. umbella, nom. pl. umbellae, acc. pl. umbellas, dat. & abl. pl. umbellis [> L. umbella,-ae (s.f.I), dim. of umbra, a little shadow, that is, a parasol, sunshade, umbrella]; see umbellula,-ae (s.f.I).

An umbel is an indeterminate inflorescence. A compressed cyme, which is a determinate inflorescence, is called umbelliform if it resembles an umbel [Wikipedia “Umbel” May 2023]: cyma umbelliformis, abl.sg. cyma umbelliformi.

- umbella bulbilis carens, capsulifera, multiflora, irregularis, umbel lacking bulbils, capsule-bearing, many-flowered, irregular.

- spatha umbellam aequans vel paulo longior vel raro brevior, spathe equalling the umbel or a little longer or rarely shorter.

- umbella simplex, simple umbel. Stearn.

- floribus in umbellas (non in racemos) dispositis, with flowers arranged into umbels (not racemes).

- bracteae sacciformes, in media umbella stipitatae (B&H), bracts sack-shaped, stalked in the middle umbel.

- [lichen] aliquando corymbus (vel umbella) apotheciiferus parum vel non evolutus, apotheciis tunc magis vel omnino sessilibus ei subconfluentibus, atque scyphus simul incomplete explicatus [expanded] (Nyl.), sometimes an apothecium-bearing corymbus [i.e. flower cluster] (or umbella) is little or not developed, with the apothecia at that time largely or completely sessile, slightly confluent with it; and the scyphus [i.e. enlargement of the podetium] at the same time is incompletely expanded.

Partial umbel: also known as the radius,-ii (s.m.II), abl. sg. radio: a ‘ray;’ “in Umbelliferae, the partial umbel” (Stearn); see partial.

Sertulum,-i (s.n.II), abl. sg. sertulo: “(obsol.) a simple umbel” (Lindley). similiflorus,-a,-um (adj.A): “applied to an umbel when its flowers are all alike” (Jackson); umbella similiflora.

Umbella universalis (adj.B), abl. sg. umbella universali: a general or compound umbel.

In algae, Sciadium arbuscula has branches arranged in an ‘umbel,’ i.e. radiating branches from a central axis:

- [Sciadium arbuscula; alga] plantula tenella, perminuta, nudo oculo vix distinguenda, habitu singulari arbusculiformi, in trunculo simplici ramorum umbellam, quoad aetatem plus minusve provectam, simplicem, compositam vel decompositam gerens(Braun), delicate, very tiny little plants, hardly distinguished by the naked eye, with a singular arbusculiform [i.e. tree-like or dendroid] habit, bearing an umbel of branches on a simple [i.e. unbranched] small trunk [i.e. main stem], as to advanced age more or less, simple, compound or decompound [i.e. several times compound].