_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. _Æquilateral_, equal-sided; opposed to oblique. _Aerial roots_, &c., 36. _Æruginous_, verdigris-colored. _Æstival_, produced in summer. _Æstivation_, 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, _alæ_), 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 white. _Albumen_ of the seed, nourishing matter stored up with the embryo, 21, 127. _Albumen_, a vegetable product, of four elements. _Albuminous_ (seeds), furnished with albumen, 21. _Alburnum_, young wood, sap-wood, 142. _Alliaceous_, with odor of garlic. _Allogamous_, close fertilization. _Alpestrine_, subalpine. _Alpine_, belonging to high mountains above the limit of forests. _Alternate_ (leaves), one after another, 29, 67. Petals are _alternate_ with the sepals, or stamens with the petals, when they stand over the intervals between them, 82. _Alveolate_, honeycomb-like. _Ament_, the scaly spike of trees like the Birch and Willow, 75. _Amentaceous_, catkin-like, or catkin-bearing. _Amorphous_, shapeless, without any definite form. _Amphicarpous_, producing two kinds of fruit. _Amphigastrium_ (plural, _amphigastria_), a peculiar stipule-like leaf of Liverworts. _Amphitropous_ ovules or seeds, 111. _Amphora_, a pitcher-shaped organ. _Amplectant_, embracing. _Amplexicaul_ (leaves), clasping the stem by the base. _Ampullaceous_, swelling out like a bottle or bladder (_ampulla_). _Amylaceous_, _Amyloid_, composed of starch (_amylum_), or starch-like. _Anandrous_, without stamens. _Anantherous_, without anthers. _Ananthous_, destitute of flowers; flowerless. _Anastomosing_, forming a net-work (_anastomosis_), as the veins of leaves, 50. _Anatropous_ ovules or seeds, 111. _Ancipital_ (_anceps_), two-edged. _Andrœcium_, a name for the stamens taken together, 98. _Andro-diœcious_, flowers staminate on one plant, perfect on another. _Androgynous_, having both staminate and pistillate flowers in the same cluster. _Androphore_, a column of united stamens, as in a Mallow. _Androus_, or _Ander_, _andra_, _andrum_, Greek in compounds for male, or stamens. _Anemophilous_, wind-loving, said of wind-fertilizable flowers, 113. _Anfractuose_, bent hither and thither as the anthers of the Squash, &c.