A Grammatical Dictionary of Botanical Latin

Velum,-i (s.n.II), abl.sg. velo, nom. & acc. pl. vela, dat. & abl. pl. velis: veil; velum, (diatoms); in Agaricales, the enclosure where the development of the sporophore occurs; see veil, volva.

Also "A membranous adaxial flap or fold of vegetative tissue wholly or partly covering the sporangial cavity of a sporophyll: in Isoetaceae" (Kiger & Porter 2001);

(diatoms) general term for a a thin, porous layer of silica obstructing (occluding) an areola (perforation, or pore); “in a loculate areola, the velum may form the external or internal wall opposite the foramen, depending on the species; = a kind of obstruction (occlusion) with pores 30 nm or more in diameter” (Diatoms of North America: web).

- velum partiale (adj.B): partial veil, abl. sg. velo partiali.

- velum pelliculare (adj.B): pellicular veil, abl. sg. velo pelliculari.

- velum cortinoideum, cortinoid veil, abl. sg. celo cortinoideo.

- velum hymeniale, partial veil of agarics, abl. sg. velo hymeniali.

- velum universale, universal veil or volva, abl. sg. velo universali.

- pileus reliquiis floccosis veli universalis instructus, pileus provided with the floccose remains of the universal veil.

- protoblema,-atis (s.n.III), abl. sg. protoblemate, primary universal veil.

- teleblema,-atis (s.n.III), abl. sg. teleblemate, the universal veil.

Apparently velum universale is as acceptable as volva universalis for "universal veil."

Velum,-i (s.n.II), q.v.: “the annulus of certain Fungals” (Lindley).

Velum,-i (s.n.II) hymeniale (adj.B), abl.sg. velo hymeniali, partial veil of agarics. Hymenial veil “the annulus in mature Amanitas, etc., of primary origin, derived from the primordial, peripedicular substance, more tardily differentiated than the volva, nonexistent in the absence of a universal veil although not derived from it (Gilbert, 1947); - a more precise term than the traditional but ambigous ‘partial veil’” (S&A).

peripedicularis,-e (adj.B): (in fungi) “of origin of the veil) arising by a proliferation of the surface of the stipe, as does the ‘partial veil’ (Kühner, 1926) > peri- ‘near, around’ + pediculus, a little foot” (S&D); see pedicularis,-e (adj.B).

NOTE: the universal veil of agarics and Gasteromycetes constitutes a layer of tissue covering the fruit-body while development takes place; = teleblem; cf. volva. The primary universal veil = protoblem (Ainsworth & Bisby), q.v.