A Grammatical Dictionary of Botanical Latin

Radius,-ii (s.m.II), abl.sg. radio: ray, beam of light (radii solis, 'rays of the sun'); in mathematics, the radius or semi-diameter of a circle; “1. the marginal portion of a Composite flower, when distinct from the disk; 2. a branch of an umbel, a partial umbel” (Jackson); in Compositae, the outer ligulate florets as distinct from the tubular florets of the disc; in Umbelliferae, the partial umbel (Stearn); ray: “any of a group of lines or processes diverging from a common center like the radii of a circle” (WIII) [> L. radius,-ii (s.m.II), a rod or staff; a semidiameter or radius of a circle; in zoology, the spur of many kinds of birds; a beam or ray of light (Lewis & Short); see ‘ray’ for umbelliferaceous examples;

NOTE: actin-, actino-: in G. comp., rayed, star-like, radiating from a center [> Gk. actis,-inos, s.f.III, ray, beam of sunlight];

- fissura ad dimidium radii attingens, fissure reaching down to half of the radius (Stearn).

- striae in radios dispositae, stiae arranged into rays.

- stipes in radios findens, stipe splitting into rays.

- capitula heterogama radiata, floribus radii uniseriatis neutris, disci hermaphroditis fertilibus, capitula heterogamous radiate, with flowers of the ray uniseriate neuter, of the disc hermaphrodite fertile

- corollae radii ligulatae, disci tubulosae, corollas of the ray ligulate, of the disc tubular (Stearn)).

- corollae radii ligulatae, ligula brevi obovata, corollas of the radius (i.e.ray-florets) ligulate, with ligula short obovate (Stearn).

- dactyli 2-cellulati quam radii penultimati paulum longiores, dactyls 2-celled than the penultimate rays a little longer (Stearn).

- fissura ad dimidium radii attingens, fissure reaching down to half of the radius (Stearn).

- stigmata radii e corolla exserta, disci inclusa, stigmas of the ray-area from the corolla exserted, of the disc included (Stearn).

- ovariis radii curtis et triquetris, with the ovaries of the ray [sc. flowers] short and triquetrous.

- flores radii neutri, ray flowers neuter.

- fructificatio in radios 6-9 obtusos vel acutos findens, fruiting body splitting into 6-9 blunt or acute rays.

- radius solis, a ray of the sun, sunbeam; radii solis, sunbeams.

- flores ochroleuci albidi v. rarius pallide coerulescentes, exteriores interdum corolla ampliore magisque irregulari radium capituli formantes (B&H), the flowers ochroleucous, whitish or more rarely pale blueish, the outer sometimes with a larger corolla and more irregular, [the exterior ones] forming the ray of the capitulum.

- elytriculi f. [i.e. ‘s.’] flosculi marginales radium formantes (Swartz), the marginal elytriculi or florets forming a ray.

NOTE: in mathematics, the radius or semi-diameter of a circle;

- fissura ad dimidium radii attingens, fissure reaching down to half of the radius (Stearn).

NOTE: the ray (radius,-ii (s.m.II) “the marginal portion of a Composite flower, when distinct from the disk (Jackson); used in the gen. singular in the following examples:

- capitula heterogama radiata vel rarius disciformia, floribus radii femineis fertilibus neutrisve, disci fertilibus sterilibusve; vel radio deficiente homogama; capitula heterogamous, ray-like or more rarely disc-shaped, with the female flowers of the ray fertile or neuter, [flowers] of the disc fertile or sterile; or [the capitula homogamous with the ray lacking.

- achaenia disci perfecta, achenes of the disc perfect.

- bracteis achaenia radii arcte involventibus, the achenes of the ray with closely enveloping bracts.

- achaenia radii bracteis concavis, achenes of the ray with concave bracts.

NOTE: I. ACTINOPHYTUM, a vocibus AKTINOEIDEIS, in speciem radiorum formatum, & phyton, planta derivatur. Planta, id est, floribus composîtis. Elytriculi l. flosculi marginales radium formantes, lingulatoplani: centrales, tubuliformes (Necker), Actinophytum, is derived from the words Aktinoeideis, ‘formed in the figure of rays,’ and phyton,’ planta.’ A plant, that is, with compound flowers. The marginal Elytriculi [l. = ‘vel’] or florets

Radius,-ii (s.m.II), abl. sg. radio: a staff, rod; stakes; spokes of a wheel; see rod.