SEEDS AND THEIR IDENTIFICATION.

New Zealand Journal of Agriculture, Volume XII, Issue 4, 20 April 1916, Page 295

SEEDS AND THEIR IDENTIFICATION.

CONTINUED.

E. BRUCE LEVY,

Biological Assistant

(i.) Rib-grass (Plantago lanceolata). (2.) Greater . Plantain ' (Pantago major). (3.) Rugel’s Plantain (Plantago Rugelii). < ~ (4.) Bracted Plantain (Plantago aristata). ■ (5.) Large-leaved Plantain (Plantago hirtella). (6.) Shore Plantain (Plantago Coronopus).

Rib-grass is a very common impurity in most agricultural seeds, and the weed itself is common in almost any pasture.

Greater plantain is fairly frequently met with. The plant is common in pastures and waste places.

Rugel’s plantain is fairly common in imported seed, but the plant has never yet been recorded growing in New Zealand.

Bracted plantain is very common in imported meadow-fescue of American origin, and is looked upon as a source-indicator for this seed. The plant itself has never been recorded in New Zealand, although the writer has raised plants from seed sown in pots, which plants produced mature seed.

Large-leaved plantain is a rare impurity, although the plant is very common throughout the Auckland District.

Shore plantain is not commonly met with. The plant is restricted almost entirely to seashores, and is very plentiful around the Hawke’s Bay District.

When present in small numbers none of the above-mentioned seeds are of any moment in lines of seed.

RIB-GRASS.

Size : Average length, tt in. ; average width, in

Colour: Amber-coloured to a dark brown, both colours often being present in the same seed.

Shape: Shaped like a shallow, thick-walled canoe, with ends rounded alike, the cavity varying in size from a mere slit to a wide shallow depression. The sides of the canoe present a folded-over appearance, and are at times folded almost to meet each other. In the centre of the cavity is a roughened, . slightly raised, and often dark-coloured scar. The. bottom of the canoe-like seed is often light amber in colour, while the walls are generally much darker. The surface of the seed is smooth and shining, the convex surface being more shiny than the concave. Occasionally a seed is met with the surface of which is somewhat minutely waved or very finely sculptured. The seeds ' are ■ borne in pairs in the seed-head, cavity to cavity. Between. each seed thus placed is a thin corky-like straw-coloured partition. This partition occasionally adheres to the one or the other seed, especially when the seed is immature. The seed ' when ' moistened for some hours becomes enveloped in a thick layer of transparent mucilage. .

GREATER PLANTAIN.

Size : Very . variable. Average length, /o in. ; average width, A in.

Colour: Light to dark brown, generally tinted with green, often quite dark-greenish to black.

Shape : Extremely variable ; oblong . and flattened, one end usually more pointed than the other ; seed often almost triangular, and often irregular in .outlineat times oval, rhomboidal, or trapezoidal in outline when lying flat. . The flat surface is generally slightly curved upwards at the ends, and at times ,is slightly twisted. The edges of the seed are acute. The inner -surface is raised gradually to a central point marked by a distinct whitish scar. This scar is generally situated about the middle of the sur-face,-but is placed at times near one end. .. This scar marks the po’nt of attachment of > the seed to the. central partition in the seed-capsule. Situated near the scar is a small depression, and radiating from this and completely covering the seed are very fine wavy lines. These lines are very distinctive, and distinguish this seed from that of Rugel’s plantain, next. described. The surface of the seed is dull and rough in appearance. The seed when wetted for some hours becomes enveloped in a thick coating of transparent mucilage. ;

rugel’s plantain.

Size : Very variable ; average length, in.; average width, 2V in.

Colour : Dark brown to black.

Shape : Very variable ; resembles greater plantain very closely, although in general the seed is larger; oblong, and more or less flattened ; often decidedly truncate ; oval, rhomboidal, or triangular in outline. The outer surface is slightly rounded and often twisted.

The inner surface is generally raised, but not so regularly as is that of greater plantain. About the middle of the inner surface is a well-marked whitish scar, but there is no small depression alongside this scar as in greater plantain. The edges of the seed are acute, and the seed is frequently acute-angled or sharply rounded at one or other of its ends. The surface of the seed is dull and rough, although not marked by raised lines as is greater plantain. The seed when wetted for some hours becomes enveloped in a thick coating of transparent mucilage.

BRACTED PLANTAIN.

Size : Average length, i in. ; average width, /o in

Colour: A fairly uniform deep brown, sometimes dark brown, relieved on the inner surface by white markings.

Shape: Typically canoe-shaped; very regular; ends rounded alike. The walls are thinner than and not folded over as in ribgrass. The inner surface is much depressed, and bears in the

middle a well-marked scar. This scar takes' the form of two depressions in line with the long axis of the seed. The two depressions are divided off from each other, and are surrounded by a whitish border. Right around the bottom, as it were, of the canoe-shaped seed is a distinct white border. This white border really runs round the edge of the inner face, and is composed of mucilage-forming tissue, as is also the white border surrounding the scar. The walls of the canoe-shaped seed are apparently continuous, but at one end is a Y-shaped slit, dark in colour and seen at the

base of the convex face at one end. From the inner surface this slit is obscured by the white mucilage-forming tissue, , but becomes evident after the seed has been wetted and the mucilage-forming tissue broken- down.' 1 The outer face is distinctly convex, and is marked about its. middle by a shallow groove extending right across the face from rim to rim. at right angles to the . longitudinal axis of the seed. The surface is in general dull and of a roughened granular appearance. The seed when moistened for a few hours becomes enveloped by a thick coating of transparent mucilage. The' white markings -on the inner face then disappear.

LARGE-LEAVED PLANTAIN.

Size : Average length, rg in. ; average width, go in.

Colour: Yellowish-green; dark green to black

Shape: Very uniform; oblong and fairly flattened; both ends rounded alike; edges- acute. The outer face is evenly convex, as is rib-grass, although not quite so rounded as is that seed; more rounded, however, than is either Rugel’s or greater plantain. The inner face is flat, not raised or depressed, and bears in its centre a well-marked whitish scar, alongside of which is* a small circular 1 depression, both in line with the longitudinal axis of the seed. These two scars can be seen much more plainly when the seed 1 has been wetted. The surface of the seed is dull and slightly: roughened by minute sculpturing over the entire surface. The seed when wetted for some hours becomes enveloped by a thick coating of transparent mucilage. ’

SHORE PLANTAIN.

Size : Very small; average length, -^ g in. ; average width, /o in.

Colour : Slatey; whitish around the margin.

Shape: Oval to obovate; both ends bluntly pointed, generally evenly so ; edges fairly acute and in general lighter in colour than the rest of the seed. The outer face is convex, and turns upwards towards the ends like the bow of a canoe. Across the middle of this face of most of the seeds, and extending from rim to rim at right angles to the longitudinal axis of the seed, is a shallow groove similar in effect to that of bracted plantain. The inner face is raised in a convex fashion, and bears at its centre a very wellmarked, deep, circular depression. The surface of the seed is dull and slightly roughened. The seed when wetted produces a copious supply of thin transparent mucilage.

grass was also noted in hard fescue, sand clover, Yorkshire fog, trefoil, sheep’s fescue, ratstail, Danthonia pilosa,’ Danthonia semiannularis, kidney-vetch, phalaris, sheep’s burnet, yarrow, crimson clover, Poa trivialis, Poa nemoralis, and strawberry clover. .. Greater plantain was also noted in Canadian blue-grass, Yorkshire fog, and Poa trivialis. , <•«

Agricultural Seed in which found. < Of ioo Samples examined Rib-grass was noted in Greater Plantain was noted in Rugel’s Plantain was noted in Bracted Plantain was noted in Largeleaved Plantain was noted in Shore . Plantain was noted in Perennial rye-grass . l6 ■ Italian rye-grass : . . 20 I I Cocksfoot 26 Crested dogstail 3° 3 I Chewings fescue '5 Timothy Fiorin 26 16 19 16 47 5 . I Meadow-foxtail • J 4 4 4 4 4 ■ • • ■ Meadow-fescue 7 64 Poa pratensis . . 64 Poa -pratensis . . . . 33 33 3 3 White clover . . . . 85 28 2 Alsike . . . 38 9 2 * Cow-grass . . 93 3 . 2 Red clover • . . ! Lucerne .. .. 94 66 5 2 3 1 I Lotus .. 1 72 8 ::

The following table, compiled from analyses made in the Biological Laboratory, shows the relative frequency of occurrence of these seeds in the main agricultural seeds :-