.

_Acephalous_, headless.

_Acerose_, needle-shaped, as the leaves of Pines.

_Acetabuliform_, saucer-shaped.

_Achaenium_, or _Achenium_ (plural _achenia_), a one-seeded, seed-like
fruit, 120.

_Achlamydeous_ (flower), without floral envelopes, 86.

_Acicular_, needle-shaped; more slender than acerose.

_Acinaciform_, scimitar-shaped, like some bean-pods.

_Acines_, the separate grains of a fruit, such as the raspberry.

_Acorn_, the nut of the Oak, 122.

_Acotyledonous_, destitute of cotyledons or seed-leaves.

_Acrogenous_, growing from the apex, as the stems of Ferns and Mosses.
_Acrogens_, or _Acrogenous Plants_, a name for the vascular cryptogamous
plants, 156.

_Aculeate_, armed with prickles, i. e. _aculei_; as the Rose and Brier.

_Aculeolate_, armed with small prickles, or slightly prickly.

_Acuminate_, taper-pointed, 54.

_Acute_, merely sharp-pointed, or ending in a point less than a right
angle, 54.

_Adelphous_ (stamens), joined in a fraternity (_adelphia_); see
_monadelphous_, &c.

_Aden_, Greek for gland. So _Adenophorous_, gland-bearing.

_Adherent_, sticking to, or more commonly, growing fast to another body.

_Adnate_, literally, growing fast to, born adherent, 95. The anther is
adnate when fixed by its whole length to the filament or its
prolongation, 101.

_Adnation_, the state of being adnate, 94.

_Adpressed_ or _appressed_, brought into contact with, but not united.

_Adscendent_, _ascendent_, or _ascending_, rising gradually upwards, 39.

_Adsurgent_, or _assurgent_, same as ascending, 39.

_Adventitious_, out of the proper or usual place; e. g. _Adventitious
buds_, 30.

_Adventive_, applied to foreign plants accidentally or sparingly
introduced into a country, but hardly to be called naturalized.

_AEquilateral_, equal-sided; opposed to oblique.

_Aerial roots_, &c., 36.

_AEruginous_, verdigris-colored.

_AEstival_, produced in summer.

_AEstivation_, the arrangement of parts in a flower-bud, 97.

_Agamous_, sexless.

_Aggregate fruits_, 118.

_Agrestis_, growing in fields.

_Air-cells_ or _Air-passages_, spaces in the tissue of leaves and some
stems, 131.

_Air-Plants_, 36.

_Akene_ or _Akenium_, 120.

_Ala_ (plural, _alae_), a wing; the side-petals of a papilionaceous
corolla, 92.

_Alabastrum_, a flower-bud.

_Alar_, situated in the forks of a stem.

_Alate_, winged.

_Albescent_, whitish, or turning white.

_Albus_, Latin for whit