from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A seed coat or testa.
from the GNU version of the Collaborative International Dictionary of English
- n. The covering of a seed; -- sometimes limited to the outer coat or testa.
from The Century Dictionary and Cyclopedia
- n. In botany the integument of a seed in the aggregate; properly, same as testa.
Sorry, no etymologies found.
Next in position to this, and covering the seed, is the so-called spermoderm, which means the seed skin, referred to in the trade as the silver skin.
With wingless seeds the main distinction is found in the spermoderm, which is entire in one species only, P. koraiensis.
I-- Cross-section of berry, natural size; _Pk_, outer pericarp; _Mk_, endocarp; _Ek_, spermoderm; _Sa_, hard endosperm; Sp, soft endosperm.
Parenchyma cells form the remainder of the spermoderm; and these are partially obliterated, so that the structure is not easily seen, appearing almost like a solid membrane.
The spermoderm is thin enough not to need sectioning.
The seed of Pinus contains an embryo, with the cotyledons clearly defined, embedded in albumen, which is protected by a bony testa with an external membranous spermoderm, produced, in most species, into an effective wing.
Cones indehiscent, from 9 to 14 cm. long, short-pedunculate, ovoid-conical or subcylindrical; apophyses dull pale nut-brown, rugose, shrinking much in drying and exposing the seeds, prolonged and tapering to a more or less reflexed tip, the umbo inconspicuous; seeds large, wingless, the spermoderm entire.
Cones from 5 to 7 cm. long, subsessile, oval or subglobose; apophyses nut-brown or fulvous brown, dull or slightly lustrous, very thick, the under surface conspicuous, meeting the upper surface in an acute margin, and terminated by a salient, often acute umbo; seed wingless, the testa bare of spermoderm.
In P. strobus, longifolia and their allies and in P. Balfouriana the spermoderm is prolonged into an effective wing-blade from a marginal adnate base like that of P. flexilis.
Seeds wingless, the spermoderm forming a narrow border with a rudimentary prolongation.