Part 158 (1/2)

ORDER 106. CERATOPHYLLaCEae. (HORNWORT FAMILY.)

_Aquatic herbs, with whorled finely dissected leaves, and minute axillary and sessile moncious flowers without floral envelopes, but with an 8--12-cleft involucre in place of a calyx, the fertile a simple 1-celled ovary, with a suspended orthotropous ovule, seed filled by a highly developed embryo with a very short radicle, thick oval cotyledons, and a plumule consisting of several nodes and leaves._--Consists only of the genus

1. CERATOPHLLUM. L. HORNWORT.

Sterile flowers of 10--20 stamens, with large sessile anthers. Fruit an achene, beaked with the slender persistent style.--Herbs growing under water, in ponds or slow-flowing streams; the sessile leaves cut into thrice-forked thread-like rigid divisions (whence the name from ???a?, _a horn_, and f?????, _leaf_).

1. C. demersum, L. Fruit smooth, marginless, beaked with a long persistent style, and with a short spine or tubercle at the base on each side.--Var. ECHINaTUM, Gray, has the fruit mostly larger (3” long), rough-pimpled on the sides, the narrowly winged margin spiny-toothed.--Slow streams and ponds, across the continent. (Eu., etc.)

SUBCLa.s.s II. GYMNOSPeRMae.

Pistil represented by an open scale or leaf, or else entirely wanting; the ovules and seeds therefore naked (without a pericarp), and fertilized by the direct application of the pollen. Cotyledons often more than two.

ORDER 107. CONiFERae. (PINE FAMILY.)

_Trees or shrubs, with resinous juice, mostly awl-shaped or needle-shaped entire leaves, and moncious or rarely dicious flowers in catkins or solitary, dest.i.tute of calyx or corolla._ Ovules orthotropous or inverted. Embryo in the axis of the alb.u.men, nearly its length. (Wood dest.i.tute of ducts, composed chiefly of a h.o.m.ogeneous large woody fibre which is marked with circular disks on two sides.)

SUBORDER I. Pinaceae. Fertile flowers in scaly aments becoming cones or berry-like. Ovules 2 or more at the base of each scale. Mostly moncious and evergreen.

Tribe I. ABIETINEae. (PINE FAMILY proper.) Fertile flowers in catkins, consisting of numerous open spirally imbricated carpels in the form of scales, each scale in the axil of a thin persistent bract; in fruit forming a strobile or cone. Ovules 2, adherent to the base of each scale, inverted. Seeds winged. Cotyledons 3--16. Anthers spirally arranged upon the stamineal column, which is subtended by involucral scales. Buds scaly. Leaves scattered (or fascicled in n. 1 and 5), linear to needle-shaped.

[*] Cones maturing the second year, their scales becoming thickened and corky.

1. Pinus. Leaves 2--5 in a cl.u.s.ter, surrounded by a sheath of scarious bud-scales.

[*][*] Cones maturing the first year, their scales remaining thin.

[+] Cones pendulous, their scales persistent; bracts smaller than the scales; leaves jointed upon a prominent persistent base, solitary.

2. Picea. Leaves sessile, keeled on both sides (tetragonal).

3 Tsuga. Leaves petioled, flat.

[+][+] Cones erect; bracts longer than the scales; leaf-scars not prominent.

4. Abies. Scales of the large cone deciduous. Leaves persistent, solitary, keeled beneath.

5. Larix. Scales of the small cone persistent. Leaves mostly fascicled, flat, deciduous.

Tribe II. TAXODIEae. Fertile aments of several spirally arranged imbricated scales, without bracts, becoming a globular woody cone.

Ovules 2 or more at the base of each scale, erect. Leaves linear, alternate; leaf-buds not scaly.

6. Taxodium. Seeds 2 to each scale. Leaves 2-ranked, deciduous.

Tribe III. CUPRESSINEae. Scales of the fertile ament few, decussately opposite or ternate, becoming a small closed cone or sort of drupe.

Ovules 2 or more in their axils, erect. Cotyledons 2 (rarely more).

Leaves decussately opposite or ternate, usually scale-like and adnate, the earlier free and subulate; leaf-buds not scaly.