Bibliographic record
Abstract
Cirsium arvense is a perennial herb. It grows from a deep, extensive, creeping root system with horizontal rhizomes, enabling vigorous asexual reproduction and the formation of dense colonies. The erect stems are slender, ribbed, and mostly unbranched (except near the inflorescence), typically ranging from 30–120 cm tall, and sparsely hairy to nearly glabrous. Leaves are alternate and lanceolate to linear-lanceolate, typically 5–30 cm long and 2–7 cm wide, deeply lobed, with irregularly toothed margins tipped by sharp yellowish spines; upper leaf surfaces are green and nearly smooth, while the lower surfaces are paler and may be thinly hairy. Both basal and cauline leaves are well developed; basal leaves are often larger and may wither by flowering time. Flowering occurs from mid-June to September. The inflorescences are clusters of small (1–2 cm) heads at the ends of stems and branches. Plants are dioecious, with male and female flowers on separate plants. Flower heads are egg-shaped, each with a series of overlapping green to purplish spiny involucral bracts, which are ovate-lanceolate and sharply pointed. The corollas are composed only of tubular disc florets, 15–20 mm long, with petals that are deeply divided into about five lobes at the tip, giving the corolla a frilled appearance and typically lavender to pink (sometimes white), fragrant, and with long, deeply lobed styles. Male heads produce pollen, while female heads are seed-producing. The fruit is a small, brownish, ribbed achene (2–4 mm) with a tuft of white, hairlike pappus for wind dispersal, maturing from late summer into fall. Canada thistle is an introduced, aggressive noxious weed in South Dakota, invading prairies, cropland, pastures, roadsides, disturbed sites, and riverbanks. It is statewide, particularly abundant in moist, disturbed soils and perennial cropping systems.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.041 | 0.026 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".