Manual of the New Zealand Flora/Lentibularieæ

by Thomas Frederick Cheeseman

Order LV. LENTIBULARIEÆ.

Herbs, either aquatic or growing in wet soil. Leaves in the terrestrial species radical, few or rosulate, entire; in the aquatic species more or less scattered, capillary and multifid. Flowers irregular, hermaphrodite, either solitary or several on a scapiform peduncle. Calyx inferior, 2-lipped or 4–5-partite. Corolla gamopetalous, hypogynous, irregular, the tube usually produced into a spur or pouch, the limb 2-lipped, upper lip entire or 2-lobed, lower lip 3–5-lobed. Stamens 2, inserted at the base of the corolla-tube; filaments usually broad, arched; anthers 1-celled. Ovary superior, globose, 1-celled; style short and thick; stigma 2-lobed; ovules numerous, on a free central placenta. Fruit a capsule, either bursting irregularly or 2-4-valved. Seeds numerous, small; albumen wanting; embryo either undivided or with very short cotyledons.

A small but very distinct order, comprising 4 genera and about 250 species. It is remarkable on account of the roots or leaves often being provided with small bladder-like appendages, which catch minute aquatic animals. The single genus found in New Zealand is almost world-wide in its distribution.

1. UTRICULARIA, Linn.

Slender herbs, floating or terrestrial. Leaves of the terrestrial species all radical, inconspicuous or fugacious; of the floating species scattered, multifid with capillary segments, furnished with floating bladders. Peduncles or scapes radical or axillary, either 1-flowered or bearing a few- or many-flowered raceme or spike. Calyx 2-partite; segments entire or nearly so, often enlarged in fruit. Corolla spurred at the base, 2-lipped; upper lip erect, entire or 2-lobed; lower lip larger, spreading, 3–6-lobed, with a palate projecting into the throat and almost closing the flower. Stamens 2; filaments incurved. Style short; stigma unequally 2-lobed. Capsule globose or nearly so, 2-valved or bursting irregularly. Seeds many.

A large genus of world-wide distribution, the species probably numbering close upon 200. With the exception of U. monanthos, which extends to Tasmania, all the New Zealand species are endemic. They are also very imperfectly known, and require a careful study from fresh specimens.

A. Stems floating. Leaves submerged, multifid; segments capillary.
Stems often several feet in length; branches with the leaves on 1½–3 in. across	1. U. protrusa.
Stems 2–6 in. long; branches with the leaves on ½ in. across	2. U. Mairii.
B. Plants stemless, growing in bogs or wet soil. Leaves all radical, few, small, narrow-linear, entire.
Flowers pale-purple. Upper lip of corolla not 2-lobed; lamina of lower lip broad, entire; spur short, obtuse	3. U. novæ-zealandiæ.
Flowers white. Upper lip of corolla 2-lobed; lamina of lower lip broad, entire; spur long, acute, minutely 2-horned at the tip	4. U. delicatula.
Upper lip of corolla 2-lobed; lamina of lower lip 3-lobed	5. U. Colensoi.
Flowers dark violet-purple. Upper lip of corolla cuneate, retuse; lamina of lower lip very broad; spur short	6. U. monanthos.

1. U. protrusa, Hook. f. Fl. Nov. Zel. i. 206.—Stems floating in still water, branched, often extending to a length of several feet, slender, filiform. Leaves numerous, all submerged, spreading, pinnately multipartite; segments many, filiform; bladders numerous, about ⅛ in. long, obliquely ovoid, shortly pedicelled, attached near the base of the segments. "Scape stout, erect, 2–4-flowered. Sepals oblong. Corolla yellow; upper lip 3-lobed; lower broader, subquadrate, its disc protruded, margins recurved. Spur short, obtuse."—Handb. N.Z. Fl. 222.

North Island: Auckland—Lake Tongonge, near Ahipara, R. H. Matthews! Lake Waihi, Waikato, Kirk! T.F.C.; Bay of Plenty, Colenso.

I have taken the description of the inflorescence, &c., from the Handbook, the plant occurring in Lakes Waihi and Tongonge not being known in a flowering state. It may not be identical with Hooker's U. protrusa, the type specimens of which have been unfortunately lost.

2. U. Mairii, Cheesem. n. sp.—Stems floating in still water, sparingly branched, 2–6 in. long, stouter than m the preceding species. Leaves numerous, all submerged, spreading, about ¼ in. long, pinnately divided into numerous capillary segments; segments broader than in U. protrusa; bladders numerous, about 1/10 in. long, attached to the segments. Flowers not seen.

North Island: Auckland—Lake Rotomahana, Kirk and Captain G. Mair! (1872).

This is certainly distinct from the Lake Waihi and Lake Tongonge plant, which has stems several feet in length, and the branches of which, with the spreading leaves, are from 1½–3 in. across. In U. Mairii the stems are much shorter and stouter, and the branches with the leaves on are only about ½ in. across. Which of the two plants corresponds to Hooker's U. protrusa can only be determined when flowering specimens are obtained. U. Mairii was destroyed in the Rotomahana locality by the eruption of 1886, but it probably occurs in some of the lakes in the Rotorua district.

3. U. novæ-zealandiæ, Hook. f. Fl. Nov. Zel. i. 206.—Stemless. Roots slender, creeping, bearing numerous shortly pedicelled bladders about ⅛ in. diam. when fully grown. Leaves 1–3, all radical, often disappearing at the time of flowering, ¼–¾ in. long, rarely more, very narrow-linear or linear-spathulate, quite entire, rather fleshy, 1-nerved. Scape or peduncle very slender, variable in length, 3–9 in. high or more, simple, erect, 1–4-flowered; bracts small, opposite or in threes. Flowers shortly pedieelled, ¼–⅓ in. long, pale-purple with a yellow eye. Upper calyx-segment orbicular or nearly so, rounded or slightly retuse at the tip; lower rather smaller, concave, 2-lobed. Upper lip of the corolla much the smaller, narrow cuneate-oblong, constricted below the middle, truncate or nearly so at the tip; lower lip with a broad horizontal almost semicircular lamina about ⅓ in. diam., margin entire; palate with three raised ridges, each with a central groove; spur short, broad, obtuse. Capsule membranous, globose, ⅙ in. diam.—Handb. N.Z. Fl. 222. U. subsimilis, Col. in Trans. N.Z. Inst. xvi. (1884) 334.

North Island: Auckland—Lake Ohia (near Mongonui), T.F.C; Great Barrier Island, Kirk! near Helensville, W. T. Ball! near Waiuku, H. Carse! Waihi, Petrie! Lake Taupo, A. Hamilton! Taranaki—Ngaire Swamp, T.F.C. Wellington—Palliser Bay, Colenso. South Island: Canterbury Plains, Armstrong. November–January.

Probably not uncommon in peaty swamps throughout the North Island, but easily overlooked.

4. U. delicatula, Cheesem. n. sp.—Habit of U. novæ-zealandiæ, but much smaller, the scape seldom more than 3 in. high. Leaves 1 or 2 or wanting, narrow-linear or narrow linear-spathulate, quite entire. Scape 1–3 in. high, slender, wiry, erect, 1–3-flowered; bracts very small. Flowers shortly pedicelled, about ⅕ in. long, white with a faint yellow eye. Calyx-segments almost equal, suborbicular, concave. Upper lip of corolla the smaller, linear-oblong, two-lobed at the tip; lower lip with a horizontally spreading lamina which is quite entire, not 3-lobed; palate very obscurely thickened or quite plane; spur longer than in U. novæ-zealandiæ, minutely 2-horned at the tip. Capsule globose, membranous, about 1 in. diam.

North Island: Auckland—Near Kaitaia, T.F.C.; near Waiuku, H. Carse! swamps near Ohaupo (Waikato), T.F.C. November–January.

This differs from U. novæ-zealandiæ in the smaller size, in the upper lip of the corolla being 2-lobed, and in the longer spur, which is minutely 2-horned at the tip. From U. Colensoi it is at once separated by the entire lower lip.

5. U. Colensoi, Hook. f. Fl. Nov. Zel. i. 206.—"Altogether like U. novæ-zealandiæ but with the upper lip of the corolla linear-oblong, 2-lobed; lower broadly cuneate, 3-lobed, middle lobe retuse, disc with 3 gibbous prominences."—Handb. N.Z. Fl. 223. (?) U. vulcanica, Col. in Trans. N.Z. Inst. xxvi. (1894) 318.

North Island: East Coast, Colenso (Handbook).

This does not seem to have been collected since its first discovery more than fifty years ago, unless Colenso's U. vulcanica be the same species. Mr. Colenso describes his plant as having a 3-lobed lower lip, but he also states that the upper lip is "subovate, obtuse," which is at variance with Hooker's description. Unfortunately, the type specimens of both species have been lost, so that no comparison can now be made.

6. U. monanthos, Hook. f. Fl. Tasm. i. 299.—A minute stemless herb. Roots or rhizome very slender, bearing several subglobose compressed bladders 1/15–1/10 diam. Leaves few, all radical, ¼–1 in. long, narrow linear-spathulate, petiolate, quite entire. Scape slender, simple, erect, ¾–4 in. high, 1- or rarely 2-flowered. Flowers large for the size of the plant, ⅓ in. diam. or more, dark violet-purple with a yellow eye. Calyx-segments oblong, obtuse. Upper lip of corolla much the smaller, broadly cuneate, retuse; lower lip expanded into a broad semicircular horizontally spreading lamina; palate glandular; spur short, obtuse. Capsule globose, membranous.—Handb. N.Z. Fl. 222.

North Island: Rangipo Plain, near Ruapehu, Petrie! South Island, Stewart Island: Not uncommon in peat-bogs in mountainous localities. Sea-level to 3500 ft. December–March.

Easily recognised by the large dark-purple flowers. For a description of the bladders, and for some notes on the fertilisation, see Mr. G. M. Thomson's paper on the fertilisation of New Zealand flowering-plants (Trans. N.Z. Inst. xiii. 278).