The Manual of the Botany of the Northern United States. Asa Gray. Читать онлайн. Newlib. NEWLIB.NET

Автор: Asa Gray
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or stigmas 2 or 3; embryo coiled or curved.

      Stipules not scarious, leaves palmately cleft or palmately compound. Cannabineæ, in Urticaceæ, 461

      Stipules scarious (or none); leaves opposite. Illecebraceæ, 426

      Stipules none; but flowers with scarious bracts. Amarantaceæ, 427

      Stipules and scarious bracts none. Chenopodiaceæ, 430

      Shrubs or trees.

      Ovules a pair in each cell of the ovary.

      Fruit 2-celled, a double samara. Acerineæ, in Sapindaceæ, 115

      Fruit a 1-celled and 1-seeded samara or a drupe. Oleaceæ, 335

      Ovules single in each cell of the

      Three-nine-celled ovary; leaves heath-like. Empetraceæ, 487

      Three-celled ovary; leaves broad. Rhamnaceæ, 111

      One–two-celled ovary; styles or stigmas 2-cleft. Urticaceæ, 461

      One-celled ovary; style and stigma single and entire.

      Anthers opening longitudinally. Thymelæaceæ, 448

      Anthers opening by uplifted valves. Lauraceæ, 446

      B. Flowers monœcious or diœcious, one or both sorts in catkins.

      1. Only one sort of flowers in catkins or catkin-like heads.

      Fertile flowers in a short catkin, head, or strobile. Urticaceæ, 461

      Fertile flowers single or clustered; sterile in slender catkins (except in Fagus).

      Leaves pinnate; fertile flowers and fruit naked. Juglandaceæ, 467

      Leaves simple; fertile flowers 1–3 in an involucre or cup. Cupuliferæ, 470

      2. Both sterile and fertile flowers in catkins or catkin-like heads.

      Ovary and pod 2-celled, many-seeded. Liquidambar, in Hamamelideæ, 180

      Ovary and pod 1-celled, many-seeded; seeds furnished with a downy tuft at one end. Salicaceæ, 480

      Ovary 1–2-celled, only one ovule in each cell; fruit 1-seeded.

      Parasitic on trees; fruit a berry. Loranthaceæ, 449

      Trees or shrubs, not parasitic.

      Calyx regular, in the fertile flower succulent in fruit. Urticaceæ, 461

      Calyx none, or rudimentary and scale-like.

      Style and stigma one, simple; the flowers in heads. Platanaceæ, 466

      Styles or long stigmas 2.

      Fertile flowers 2 or 3 at each scale of the catkin. Cupuliferæ, 470

      Fertile flowers single under each scale; nutlets naked, waxy-coated or drupe like. Myricaceæ, 469

      Subclass II. GYMNOSPERMÆ. Pistil an open scale or altered leaf, bearing naked ovules on its margin or its upper surface, or in Taxus entirely wanting. Flowers monœcious or diœcious. Coniferæ, 489

      Class II. MONOCOTYLEDONOUS PLANTS. (See p. 15.)

      A. Spadiceous Division. Flowers aggregated on a spadix or fleshy axis, or sometimes scattered, destitute of calyx and corolla (excepting some Araceæ and Naiadaceæ, where, however, they are on a spadix), and also without glumes (husky scales). Leaves sometimes with netted veins.

      Little floating aquatics, with no distinction of stem and foliage. Lemnaceæ, 551

      Immersed aquatics, branching and leafy. Naiadaceæ, 557

      Reed-like or Flag-like marsh herbs, with linear and sessile nerved leaves; flowers in spikes or heads.

      Flowers monœcious, and quite destitute of floral envelopes. Typhaceæ, 547

      Flowers perfect, on a lateral spadix; sepals 6. Acorus, in Araceæ, 550

      Terrestrial or marsh plants; leaves mostly with a distinct netted-veined blade, petioled. Araceæ, 548

      B. Petaloideous Division. Flowers not collected on a spadix, furnished with floral envelopes (perianth) answering to calyx or to both calyx and corolla, either herbaceous or colored and petal-like (wholly glumaceous in Juncaceæ).

      1. Perianth adherent to the whole surface of the ovary.

      Flowers diœcious (or rarely perfect), regular.

      Aquatics; ovules and seeds several or numerous. Hydrocharidaceæ, 495

      Twiners; ovules and seeds one or two in each cell. Dioscoreaceæ, 517

      Flowers perfect; ovules and seeds usually numerous.

      Stamens only one or two; flower irregular, gynandrous. Orchidaceæ, 497

      Stamens three.

      Anthers introrse, opening transversely. Burmanniaceæ, 496

      Anthers introrse or versatile, opening lengthwise. Hæmodoraceæ, 512

      Anthers extrorse, opening lengthwise. Iridaceæ, 513

      Stamens 6; flowers usually on a scape from a bulb. Amaryllidaceæ, 515

      2. Perianth adherent only to the base or lower half of the ovary.

      Perianth woolly or roughish-mealy; leaves often equitant. Hæmodoraceæ, 512

      Perianth smooth; the leaves grass-like. Stenanthium, etc., in Liliaceæ, 517

      3. Perianth wholly free from the ovary.

      Pistils numerous or few in a head or ring. Alismaceæ, 553

      Pistil one, compound (cells or placentæ mostly 3).

      Perianth not glumaceous or chaffy; flowers not in dense heads.

      Stamens 6 (in Maianthemum 4), similar and perfect.

      Scurfy-leaved epiphyte; seeds hairy-tufted. Bromeliaceæ, 511

      Marsh herbs; carpels nearly distinct or separating closed from the axis; seed without albumen. Juncagineæ, in Naiadaceæ, 557

      Terrestrial, not rush-like; seeds with albumen.

      Perianth of similar divisions or lobes, mostly colored. Liliaceæ, 517

      Perianth of 3 foliaceous and green sepals and 3 colored withering-persistent petals. Trillium in Liliaceæ, 517

      Perianth of 3 persistent green sepals, and 3 ephemeral deliquescent petals. Commelinaceæ, 538

      Stamens 6, dissimilar, or only three with perfect anthers.

      Sepals 3, herbaceous; ephemeral petals 3, unequal. Commelinaceæ, 538

      Perianth tubular, 6-lobed. Pontederiaceæ, 535

      Stamens 3, similar. Moss-like aquatic. Mayaceæ, 537

      Perianth wholly glumaceous, of 6 similar divisions. Juncaceæ, 539

      Perianth partly glumaceous or chaff-like; flowers in very dense heads.